现互联网公司后端架构常用到Spring+SpringMVC+MyBatis,通过Maven来构建。通过学习,我已经掌握了基本的搭建过程,写下基础文章为而后的深入学习奠定基础。
首先说一下这篇文章的主要内容分为:
1、Maven多模块项目的创建;
2、Maven与SpringMVC的整合;
3、Dubbo的环境配置及与整合;
4、新手在整合过程易犯的错误。
通过一个简单的demo来说明,大家多多指教,分享经验!
一、Maven多模块项目的创建
我们需要建立一个多模块的maven项目,其目录结构为
其中student-api用于暴露接口;student-service用语处理业务逻辑及调用数据访问对象,返回相应数据;student-web主要用于提供dubbo服务,及其他db、spring、springMVC、mybatis等配置。这样设计能够将业务逻辑与数据访问隔离开,同时贴合了spring目标之一,就是允许我们在开发应用的程序时,能够遵循面向对象(OO)原则中的“针对接口编程”,很大程度上达到松耦合。这里将接口API隔离出来作为dubbo生产者的服务接口,供消费应用调用(在后续详细讲解)。
1.新建Maven项目
2.选择项目存放路径后,选择创建一个简单的maven项目
3.填写GroupId和ArtifactId,注意选择或者填写版本号
点击完成后,建立好了student-demo项目。之后删除项目src目录,打开pom.xml将<packaging>jar</packaging>修改为<packaging>pom</packaging>,pom表示它是一个被继承的模块。修改后的pom.xml如下
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion> <groupId>com.student.demo</groupId>
<artifactId>student-demo</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>pom</packaging> <name>student-demo</name>
<url>http://maven.apache.org</url> <properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<!--模块建立好以后自动生成的-->
<modules>
<module>student-service</module>
<module>student-api</module>
<module>student-web</module>
</modules>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
在建成的项目student-demo上右键选择Maven Module后创建子项目student-api。
填写子模块名字:
项目类型选择:
点击完成,建立好第一个模块后,同样的过程建立好student-service模块和student-web模块,需要注意的是student-web选择的maven类型是:
修改子模块项目目录中的pom.xml文件,把<groupId>XXX</groupId>和<version>1.0.0-SNAPSHOT</version>去掉,加上<packaging>jar</packaging>,因为groupId和version会继承student-demo中的groupId和version,packaging设置打包方式为jar。例如修改后的student-service模块的pom.xml如下:
<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.student.demo</groupId>
<artifactId>student-demo</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent> <artifactId>student-service</artifactId>
<packaging>jar</packaging>
</project>
至此,maven多模块项目已经创建完成,现在我们需要在student-demo项目的pom中增加<dependencyManagement>标签定义可被子项目继承的第三方依赖包,打包配置,资源插件等,同时注意统一定义依赖的版本,避免冲突。这里还利用Maven配置了profiles,可根据情况增加不同的运行环境,并方便快捷地切换项目运行环境,目前我们只设置了dev开发环境。
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion> <groupId>com.student.demo</groupId>
<artifactId>student-demo</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>pom</packaging> <properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<dep.ver.lombok>1.16.10</dep.ver.lombok>
<dep.ver.druid>1.0.1</dep.ver.druid>
<dep.ver.mysql>5.1.21</dep.ver.mysql>
<dep.ver.springframework>4.2.5.RELEASE</dep.ver.springframework>
<dep.ver.mybatis>3.3.0</dep.ver.mybatis>
<dep.ver.mybatis-spring>1.3.0</dep.ver.mybatis-spring>
<dep.ver.pagehelper>4.1.6</dep.ver.pagehelper>
<dep.ver.aspectjrt>1.5.4</dep.ver.aspectjrt>
<dep.ver.aspectjweaver>1.8.0</dep.ver.aspectjweaver>
<dep.ver.servlet>3.1.0</dep.ver.servlet>
<dep.ver.orika-core>1.4.6</dep.ver.orika-core>
<dep.ver.javassist>3.20.0-GA</dep.ver.javassist>
<dep.ver.paranamer>2.7</dep.ver.paranamer>
<dep.ver.concurrentlinkedhashmap-lru>1.4.2</dep.ver.concurrentlinkedhashmap-lru>
<dep.ver.gson>2.2.4</dep.ver.gson>
<dep.ver.guava>15.0</dep.ver.guava>
<dep.ver.slf4j>1.7.21</dep.ver.slf4j>
<dep.ver.logback>1.1.7</dep.ver.logback>
<dep.ver.log4j>1.2.12</dep.ver.log4j>
<dep.ver.slf4j-log4j12>1.7.5</dep.ver.slf4j-log4j12>
<dep.ver.logback-ext-spring>0.1.2</dep.ver.logback-ext-spring>
<dep.ver.dubbo>2.5.3</dep.ver.dubbo>
<dep.ver.zookeeper>3.4.8</dep.ver.zookeeper>
<dep.ver.zkclient>0.8</dep.ver.zkclient>
<dep.ver.commons-lang3>3.1</dep.ver.commons-lang3>
<dep.ver.jackson>1.9.12</dep.ver.jackson>
<dep.ver.shiro>1.2.3</dep.ver.shiro>
<dep.ver.freemarker>2.3.22</dep.ver.freemarker>
<dep.ver.commons-beanutils>1.9.2</dep.ver.commons-beanutils>
<dep.ver.junit>4.11</dep.ver.junit>
<dep.ver.mockito>1.10.19</dep.ver.mockito>
<dep.ver.joda-time>2.9.3</dep.ver.joda-time>
<dep.ver.commons-collections4>4.1</dep.ver.commons-collections4>
<dep.ver.httpclient>4.5.2</dep.ver.httpclient> <dep.ver.fastjson>1.2.11</dep.ver.fastjson> <plg.ver.maven-resources-plugin>2.7</plg.ver.maven-resources-plugin>
<plg.ver.maven-compiler-plugin>2.5.1</plg.ver.maven-compiler-plugin>
<plg.ver.maven-source-plugin>3.0.0</plg.ver.maven-source-plugin>
<plg.ver.lombok-maven-plugin>1.14.8.0</plg.ver.lombok-maven-plugin> <jdk.ver>1.8</jdk.ver>
<encoding>UTF-8</encoding>
<center.project.name>${project.artifactId}</center.project.name>
<profiles.dir>src/profiles</profiles.dir>
<jackson.version>2.6.0</jackson.version>
</properties>
<modules>
<module>student-service</module>
<module>student-api</module>
<module>student-web</module>
</modules> <dependencies>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-validator</artifactId>
<version>5.2.4.Final</version>
</dependency>
</dependencies> <dependencyManagement>
<dependencies>
<!-- spring -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${dep.ver.springframework}</version>
<exclusions>
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${dep.ver.springframework}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${dep.ver.springframework}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${dep.ver.springframework}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${dep.ver.springframework}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${dep.ver.springframework}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>${dep.ver.springframework}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
<version>${dep.ver.springframework}</version>
</dependency>
<!-- spring -->
<!-- db -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>${dep.ver.druid}</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>${dep.ver.mysql}</version>
</dependency>
<!-- db -->
<!-- mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>${dep.ver.mybatis}</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>${dep.ver.mybatis-spring}</version>
</dependency>
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>${dep.ver.pagehelper}</version>
</dependency>
<!-- mybatis -->
<!-- apache -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>${dep.ver.commons-lang3}</version>
</dependency>
<!-- apache -->
<!-- commons-beanutils -->
<dependency>
<groupId>commons-beanutils</groupId>
<artifactId>commons-beanutils</artifactId>
<version>${dep.ver.commons-beanutils}</version>
<exclusions>
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- commons-beanutils -->
<!-- log -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${dep.ver.slf4j}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>log4j-over-slf4j</artifactId>
<version>${dep.ver.slf4j}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
<version>${dep.ver.slf4j}</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>${dep.ver.logback}</version>
</dependency>
<!-- log -->
<!-- dubbo -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<version>${dep.ver.dubbo}</version>
<exclusions>
<exclusion>
<artifactId>spring</artifactId>
<groupId>org.springframework</groupId>
</exclusion>
<exclusion>
<artifactId>netty</artifactId>
<groupId>org.jboss.netty</groupId>
</exclusion>
</exclusions>
</dependency>
<!-- dubbo -->
<!-- zookeeper -->
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>${dep.ver.zookeeper}</version>
<exclusions>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.101tec</groupId>
<artifactId>zkclient</artifactId>
<version>${dep.ver.zkclient}</version>
<exclusions>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- zookeeper -->
<!-- jackson -->
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-core-asl</artifactId>
<version>${dep.ver.jackson}</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>${dep.ver.jackson}</version>
</dependency>
<!-- jackson -->
<!-- aspectj -->
<dependency>
<groupId>aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>${dep.ver.aspectjrt}</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>${dep.ver.aspectjweaver}</version>
</dependency>
<!-- aspectj -->
<!-- servlet -->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>${dep.ver.servlet}</version>
<scope>provided</scope>
</dependency>
<!-- servlet -->
<!-- javassist -->
<dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
<version>${dep.ver.javassist}</version>
</dependency>
<!-- javassist -->
<!-- test start -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${dep.ver.junit}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${dep.ver.springframework}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-core</artifactId>
<version>${dep.ver.mockito}</version>
<scope>test</scope>
</dependency>
<!-- test end -->
<!-- google -->
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>${dep.ver.gson}</version>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>${dep.ver.guava}</version>
</dependency>
<!-- google -->
<!-- lombok -->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>${dep.ver.lombok}</version>
</dependency>
<!-- lombok -->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-collections4</artifactId>
<version>${dep.ver.commons-collections4}</version>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>${dep.ver.httpclient}</version>
<exclusions>
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
</dependencyManagement> <profiles>
<profile>
<id>local</id>
<build>
<resources>
<resource>
<directory>${profiles.dir}/local</directory>
</resource>
</resources>
</build>
</profile> <profile>
<id>dev</id>
<build>
<resources>
<resource>
<directory>${profiles.dir}/dev</directory>
</resource>
</resources>
</build>
</profile>
</profiles> <build>
<finalName>${center.project.name}</finalName> <plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>${plg.ver.maven-resources-plugin}</version>
<configuration>
<encoding>${encoding}</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${plg.ver.maven-compiler-plugin}</version>
<configuration>
<source>${jdk.ver}</source>
<target>${jdk.ver}</target>
<encoding>${encoding}</encoding>
</configuration>
</plugin>
<plugin>
<artifactId>maven-source-plugin</artifactId>
<version>${plg.ver.maven-source-plugin}</version>
<configuration>
<attach>true</attach>
</configuration>
<executions>
<execution>
<phase>compile</phase>
<goals>
<goal>jar</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
</project>
在student-api中继承父pom的依赖,并且直接引入。
<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.student.demo</groupId>
<artifactId>student-demo</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<artifactId>student-api</artifactId> <dependencies>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>${dep.ver.fastjson}</version>
</dependency> <dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
</dependency>
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
</dependency>
<!-- google -->
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
</dependency>
<!-- google --> </dependencies>
</project>
在student-service中添加继承依赖,添加对student-api的依赖。
<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.student.demo</groupId>
<artifactId>student-demo</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<artifactId>student-service</artifactId> <dependencies>
<dependency>
<groupId>com.student.demo</groupId>
<artifactId>student-api</artifactId>
<version>1.0.0-SNAPSHOT</version>
</dependency> <dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>${dep.ver.fastjson}</version>
</dependency> <!-- oss相关依赖 -->
<dependency>
<groupId>com.aliyun.oss</groupId>
<artifactId>aliyun-sdk-oss</artifactId>
<version>2.0.7</version>
<exclusions>
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- oss相关依赖 结束 --> <!-- db -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!-- db --> <!-- mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
</dependency>
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
</dependency>
<!-- mybatis --> <!-- spring配置 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-aspects</artifactId>
</dependency>
<!-- spring配置 --> <!-- jackson -->
<!-- <dependency> -->
<!-- <groupId>org.codehaus.jackson</groupId> -->
<!-- <artifactId>jackson-core-asl</artifactId> -->
<!-- </dependency> -->
<!-- <dependency> -->
<!-- <groupId>org.codehaus.jackson</groupId> -->
<!-- <artifactId>jackson-mapper-asl</artifactId> -->
<!-- </dependency> -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson.version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${jackson.version}</version>
</dependency>
<!-- jackson --> <!-- log -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>log4j-over-slf4j</artifactId>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
</dependency>
<!-- log --> <!-- google -->
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
</dependency>
<!-- <dependency> -->
<!-- <groupId>com.google.code.gson</groupId> -->
<!-- <artifactId>gson</artifactId> -->
<!-- </dependency> -->
<!-- google --> <dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
</dependency> <dependency>
<groupId>commons-beanutils</groupId>
<artifactId>commons-beanutils</artifactId>
</dependency> <dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
</dependency> <dependency>
<groupId>org.javassist</groupId>
<artifactId>javassist</artifactId>
</dependency> <!-- aspectj -->
<dependency>
<groupId>aspectj</groupId>
<artifactId>aspectjrt</artifactId>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
</dependency>
<!-- aspectj --> <!-- dubbo -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>dubbo</artifactId>
<exclusions>
<exclusion>
<artifactId>spring</artifactId>
<groupId>org.springframework</groupId>
</exclusion>
<exclusion>
<artifactId>netty</artifactId>
<groupId>org.jboss.netty</groupId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.101tec</groupId>
<artifactId>zkclient</artifactId>
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- dubbo --> <dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
</dependency> <dependency>
<groupId>cglib</groupId>
<artifactId>cglib</artifactId>
<version>3.1</version>
</dependency>
</dependencies>
</project>
在student-web中继承依赖,添加对student-api,student-service的依赖。注意子项目依赖版本都为<version>1.0.0-SNAPSHOT</version>
<?xml version="1.0"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.student.demo</groupId>
<artifactId>student-demo</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<artifactId>student-web</artifactId>
<packaging>war</packaging>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
</dependency> <dependency>
<groupId>com.student.demo</groupId>
<artifactId>student-api</artifactId>
<version>1.0.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>com.student.demo</groupId>
<artifactId>student-service</artifactId>
<version>1.0.0-SNAPSHOT</version>
</dependency>
</dependencies>
<build>
<finalName>student-web</finalName>
</build>
</project>
二、Maven与SpringMVC的整合
1.第一部分已经在项目pom文件中配置了spring的相关依赖
2.在student-web项目根路径上添加profiles源目录及配置文件
注意是建立源文件不是普通文件夹。
然后在此源文件夹下建立普通文件夹props,用于存放配置文件。在props下新建db-config.properties资源文件,用于配置mysql,其配置内容为:
database.database=mysql
database.driverClassName=com.mysql.jdbc.Driver
database.url=jdbc:mysql://172.0.0.1:3306/student_data?characterEncoding=utf8
database.user=root
database.password=root
database.show_sql=true
在mysql数据库中建立一张简单的student数据表,其结构为:
3.在student-web的src/main/resources目录中新建spring文件夹,新建spring-base.xml和spring-dispatcher.xml。其中值得说明一下的是,spring监听器ContextLoaderListener和控制器DispatcherServlet会加载应用上下文。其中上下文参数contextConfigLocation的value值是根应用上下文路径classpath:spring/spring-base.xml,它会被ContextLoaderListener加载bean定义。spring-base.xml中的内容为:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd"> <!-- 开启aspectj自动注解 -->
<aop:aspectj-autoproxy proxy-target-class="true" /> <context:component-scan base-package="org.student" />
<context:annotation-config /> <!-- 配置文件加载 -->
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="order" value="1" />
<property name="ignoreUnresolvablePlaceholders" value="true" />
<property name="locations">
<list>
<value>classpath:props/db-config.properties</value>
</list>
</property>
</bean>
<import resource="classpath:spring/spring-db.xml" />
</beans>
同样DispatcherServlet会从classpath:spring/spring-dispatcher.xml加载它的bean。
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd"> <mvc:annotation-driven>
<mvc:message-converters>
<bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter " />
</mvc:message-converters>
</mvc:annotation-driven> <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter" />
<!-- 相当于注册了DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter两个bean,配置一些messageconverter。即解决了@Controller注解的使用前提配置 -->
</beans>
4.在Web.xml中声明DispatcherServlet
SpringMVC所有请求都会通过一个前端控制器DispatcherServlet,通过这个控制器将请求委托给应用程序的其它执行单元来处理,所以需要通过web.xml来注册。打开student-web项目目录下src/main/webapp/WEB-INF/web.xml,修改web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
id="schedule-console" version="3.0">
<display-name>student-web</display-name> <!-- web.xml中加载顺序是 context-param -> listener -> filter -> servlet -->
<!-- spring基础配置文件位置 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/spring-base.xml</param-value>
</context-param> <!-- Spring监听 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 设置servlet编码开始 -->
<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- 设置servlet编码结束 -->
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/spring-dispatcher.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
5.spring与Mybatis的整合
在student-web的src/main/resources目录中新建mybatis文件夹,再在此目录新建mybatis.xml和mapper文件夹。在spring文件夹下新建spring-db.xml用于spring加载mybatis配置。spring-db.xml内容如下:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd"> <!-- 采用druid作为连接池 -->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
init-method="init" destroy-method="close">
<!-- 基本属性 url、user、password -->
<property name="driverClassName" value="${database.driverClassName}" />
<property name="url" value="${database.url}" />
<property name="username" value="${database.user}" />
<property name="password" value="${database.password}" /> <!-- 配置初始化大小、最小、最大 -->
<property name="initialSize" value="1" />
<property name="minIdle" value="1" />
<property name="maxActive" value="20" /> <!-- 配置获取连接等待超时的时间 -->
<property name="maxWait" value="60000" /> <!-- 配置间隔多久才进行一次检测,检测需要关闭的空闲连接,单位是毫秒 -->
<property name="timeBetweenEvictionRunsMillis" value="60000" /> <!-- 配置一个连接在池中最小生存的时间,单位是毫秒 -->
<property name="minEvictableIdleTimeMillis" value="300000" />
<property name="validationQuery" value="SELECT 'x'" />
<property name="testWhileIdle" value="true" />
<property name="testOnBorrow" value="false" />
<property name="testOnReturn" value="false" /> <!-- 打开PSCache,并且指定每个连接上PSCache的大小 -->
<property name="poolPreparedStatements" value="true" />
<property name="maxPoolPreparedStatementPerConnectionSize"
value="20" /> <!-- 配置监控统计拦截的filters -->
<property name="filters" value="stat" />
</bean> <!-- 配置mybatis的sqlSessionFactory -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="configLocation" value="classpath:mybatis/mybatis.xml" />
<property name="mapperLocations" value="classpath:mybatis/mapper/*.xml" />
</bean> <!-- mybatis mapper接口扫描 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="org.student.service.mapper" />
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
</bean> <bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean> <!-- 开启@Transactional事务注解 -->
<tx:annotation-driven transaction-manager="transactionManager" />
</beans>
三、Dubbo的环境配置及与整合
我们已经搭建好student-demo项目来作为provider,为其它服务提供接口,所以我们需要先配置好dubbo提供者,PS:这里不会讲解zookeeper的搭建,请自行百度。其项目结构为:
1.首先在student-web中配置dubbo
由于我们已经在student-demo中添加了dubbo和zookeeper的相关依赖,下一步字啊resources目录中建立dubbo文件夹,再新建dubbo-producer.xml,同时在profiles的dev环境中添加dubbo-producer.properties配置文件,设置zookeeper注册中心暴露服务地址,配置group分组,服务端口,注册中心请求超时时间(毫秒)和版本。其中组别+接口地址+版本号唯一的标识了一个接口。文件内容为:
student-registry-address=172.0.0.1:2181
student-group=student-min
student-service-port=22026
student-timeout=120000
student-version=1.0.0
这样我们就可以来配置dubbo-producer.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://code.alibabatech.com/schema/dubbo
http://code.alibabatech.com/schema/dubbo/dubbo.xsd"> <context:property-placeholder location="classpath:props/dubbo-producer.properties" ignore-unresolvable="true"/> <dubbo:application name="provider-student-demo"/>
<dubbo:registry address="${student-registry-address}" protocol="zookeeper"/>
<dubbo:protocol name="dubbo" port="${student-service-port}" accesslog="true" />
</beans>
2.写一个简单的服务接口
1)首先在student-service中建立Student实体类
package org.student.bean; public class Student {
private Long id;
private String name;
private Integer age;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
} }
2)同时在student-api中建立与实体bean对应的DTO类实现Serializable接口,并重写toString方法。一般为了不破坏实体类和数据库表一一对应的接口,我们会新建一个DTO实体类,并且加入一些冗余的字段,作为前后端的传输对象。
package org.student.api.dto; import java.io.Serializable; public class StudentDTO implements Serializable{ private static final long serialVersionUID = 1L;
private Long id;
private String name;
private Integer age;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
} @Override
public String toString() {
return "id = " + id + ", name = " + name + ",age = " + age;
} }
3)在student-api中建立StudentApi接口,值得注意的是@service注解中的对象
package org.student.api; import java.util.List; import org.student.api.dto.StudentDTO; public interface StudentApi {
List<StudentDTO> listStudents();
}
4)在dubbo-producer.xml中注册StudentApi,添加配置:
<dubbo:service interface="org.student.api.StudentApi" ref="studentApi" group="${student-group}" version="${student-version}" timeout="${student-timeout}" />
5)从service业务逻辑层子模块开始编写接口实现,新建在student-service中新建StudentBiz实现StudentApi接口
package org.student.service.biz; import java.util.List; import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.student.api.StudentApi;
import org.student.api.dto.StudentDTO;
import org.student.bean.Student;
import org.student.service.StudentService; import com.google.common.collect.Lists; @Service("studentApi")
public class StudentBiz implements StudentApi{
private Logger logger = LoggerFactory.getLogger(StudentBiz.class); @Autowired
private StudentService studentService; @Override
public List<StudentDTO> listStudents() {
List<Student> listStudent = studentService.listStudent();
List<StudentDTO> listStudentDTO = Lists.newArrayList();
for(Student student: listStudent){
StudentDTO studentDTO = new StudentDTO();
studentDTO.setId(student.getId());
studentDTO.setAge(student.getAge());
studentDTO.setName(student.getName());
listStudentDTO.add(studentDTO);
}
return listStudentDTO;
}
}
6)在student-service中创建service层接口StudentService
package org.student.service; import java.util.List; import org.springframework.stereotype.Service;
import org.student.bean.Student; @Service
public interface StudentService { List<Student> listStudent(); }
7)在student-service中实现StudentService接口
package org.student.service.impl; import java.util.List; import javax.annotation.Resource; import org.springframework.stereotype.Service;
import org.student.bean.Student;
import org.student.service.StudentService;
import org.student.service.mapper.StudentMapper; @Service("studentService")
public class StudentServiceImpl implements StudentService{ @Resource
private StudentMapper studentMapper; @Override
public List<Student> listStudent() {
List<Student> listStudent = studentMapper.listStudent();
return listStudent;
} }
8)在student-service中创建数据层StudentMapper接口
package org.student.service.mapper; import java.util.List; import org.student.bean.Student; public interface StudentMapper {
List<Student> listStudent();
}
9)在student-web中创建实体映射的XML文件,注意StudentMapper类与sql ID的对应关系
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="org.student.service.mapper.StudentMapper">
<!--查询字段-->
<sql id="columns">
a.id,
a.name,
a.age
</sql> <!--查询结果集-->
<resultMap id="beanMap" type="org.student.bean.Student">
<result property="id" column="id"/>
<result property="name" column="name"/>
<result property="age" column="age"/>
</resultMap> <!--根据主键获取实体-->
<select id="listStudent" resultMap="beanMap">
SELECT
<include refid="columns"/>
FROM
student a
</select> </mapper>
dubbo提供者已创建完成,创建完成子应用结构为
3.为了更好的验证,需要创建一个消费者,跳用dubbo接口,其项目结构与子项目student-web类似,Maven项目类型为Webapp project。为了不冗余介绍,请参考Maven项目搭建方式。其将建完成的结构为:
作为消费者,student-test项目的dubbo配置有所不同
1)dubbo-consumer.properties的service-group应该与提供者一致,否者找不到提供者方的接口。同时pom.xml中需要增加对的依赖
<dependency>
<groupId>com.student.demo</groupId>
<artifactId>student-api</artifactId>
<version>1.0.0-SNAPSHOT</version>
</dependency>
student-registry-address=172.0.0.1:2181
student-service-group=student-min
student-service-version=1.0.0
student-service-timeout=120000
2)spring-dubbo-consumer.xml的配置及接口调用方式
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://code.alibabatech.com/schema/dubbo
http://code.alibabatech.com/schema/dubbo/dubbo.xsd"> <dubbo:application name="consumer-student-test" /> <dubbo:registry address="${student-registry-address}" protocol="zookeeper" /> <dubbo:reference id="studentApi" interface="org.student.api.StudentApi"
group="${student-service-group}" version="${student-service-version}"
check="false" /> </beans>
3)调用者的controller层
package org.student.controller; import javax.annotation.Resource; import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import org.student.api.StudentApi; @RestController
@RequestMapping("/student")
public class StudentController {
private static Logger logger = LoggerFactory.getLogger(StudentController.class); @Resource
private StudentApi studentApi; @RequestMapping(path = "/listStudent", method = RequestMethod.POST)
public void listStudent(){
logger.info("get students...");
logger.info("the data are " + studentApi.listStudents());
}
}
4)服务器同时启动provider和consumer,会看到启动信息
查看zookeeper注册中心发现提供者消费者都已成功注册
5)测试接口
由于我并没有写view层来展示数据,现在只能通过控制台的日志信息来简单测试接口。(logback的用法不做解释)利用浏览器post请求访问
http://172.0.0.1:8080/student-test/student/listStudent,控制台输出为
[http-nio-8080-exec-2] INFO 2016-11-07 18:33:24.450 o.s.c.StudentController[24] - get students...
[DubboServerHandler-172.28.19.7:22026-thread-2] INFO 2016-11-07 18:33:24.729 d.a.o.s.a.StudentApi[58] - [DUBBO] [2016-11-07 18:3:24] 172.28.19.7:56346 -> 172.28.19.7:22026 - student-min/org.student.api.StudentApi:1.0.0 listStudents() , dubbo version: 2.5.3, current host: 127.0.0.1
[http-nio-8080-exec-2] INFO 2016-11-07 18:33:25.026 o.s.c.StudentController[25] - the data are [id = 1, name = 张三,age = 20]
四、新手在整合过程易犯的错误。
1.ClassNotFound异常
严重: Error configuring application listener of class org.springframework.web.context.ContextLoaderListener
java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:)
at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:)
at java.util.concurrent.FutureTask.run(FutureTask.java:)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:)
at java.lang.Thread.run(Thread.java:)
eclipse会自动将deployment assembly指定的工程,打成jar包,放入到web-inf/lib目录下,tomcat在发布项目的时候没有同时发布maven依赖所添加的jar包,但是如果在deployment assembly没有配置相应的依赖包,就会抛出异常。解决方法:项目 —> properties -> Deployment Assembly -> Add -> Java Build Path Entries -> 选择Maven Dependencies -> Finish -> OK 把对应的Maven依赖包也发布到tomcat,调试时会自动把那些jar发布到指定目录下,tomcat也能找到那些jar了。
另外,同样的报错可能由于不同的原因造成,如果没有激活Maven profile也会报这种错误,激活profile的方式有很多,通过命令首先需要在pom.xml中用<profiles>配置(详细配置请查看上文)再通过命令行:
mvn install -Pdev #激活dev环境
也可以通过eclipse的配置:项目-->properties-->Maven-->填写profile名-->apply-->finish
2.启动student-web,spring创建bean对象失败
十一月 , :: 下午 org.apache.catalina.core.StandardContext listenerStart
严重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.student.api.StudentApi': Cannot resolve reference to bean 'studentApi' while setting bean property 'ref'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'studentApi' is defined
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:)
...
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:)
...
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'studentApi' is defined
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:)
at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:)
at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:)
...
spring有强大的注解帮助我们简化很大部分代码,并降低的耦合。@Autowired或@Resource在 Bean 类中使用自动注入功能,但是 Bean 还是在 XML 文件中通过 <bean> 进行定义 —— 也就是说,在 XML 配置文件中定义 Bean,通过@Autowired或@Resource为 Bean 的成员变量、方法入参或构造函数入参提供自动注入的功能。以前通过在spring文件中配置<bean>的方式被移除,仅需要添加一行 <context:component-scan/> 配置就解决所有问题了——Spring XML 配置文件得到了极致的简化。<context:component-scan/> 的 base-package 属性指定了需要扫描的类包,类包及其递归子包中所有的类都会被处理。解决:在spring-base.xml中添加
<context:component-scan base-package="org.student" />
3.消费者访问dubbo接口被拒绝
严重: Servlet.service() for servlet [dispatcher] in context with path [] threw exception [Request processing failed; nested exception is com.alibaba.dubbo.rpc.RpcException: Forbid consumer 172.0.0.1 access service org.student.api.StudentApi from registry 172.0.0.1:2181 use dubbo version 2.5., Please check registry access list (whitelist/blacklist).] with root cause
com.alibaba.dubbo.rpc.RpcException: Forbid consumer 172.0.0.1 access service org.student.api.StudentApi from registry 172.0.0.1:2181 use dubbo version 2.5.3, Please check registry access list (whitelist/blacklist). at com.alibaba.dubbo.registry.integration.RegistryDirectory.doList(RegistryDirectory.java:) at com.alibaba.dubbo.rpc.cluster.directory.AbstractDirectory.list(AbstractDirectory.java:) at com.alibaba.dubbo.rpc.cluster.support.AbstractClusterInvoker.list(AbstractClusterInvoker.java:) at com.alibaba.dubbo.rpc.cluster.support.AbstractClusterInvoker.invoke(AbstractClusterInvoker.java:) at com.alibaba.dubbo.rpc.cluster.support.wrapper.MockClusterInvoker.invoke(MockClusterInvoker.java:) at com.alibaba.dubbo.rpc.proxy.InvokerInvocationHandler.invoke(InvokerInvocationHandler.java:) at com.alibaba.dubbo.common.bytecode.proxy0.listStudents(proxy0.java) at org.student.controller.StudentController.listStudent(StudentController.java:) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:) at java.lang.reflect.Method.invoke(Method.java:)
....
如果消费者访问的接口路径不正确,则无法调用接口。出现这种错误是我没有把消费者的组设置成提供者的组,解决方法是group保持一致
4.访问所有接口都报404错误
INFO 2016-11-08 12:42:28.507 o.s.w.s.DispatcherServlet[488] - FrameworkServlet 'dispatcher': initialization started
INFO 2016-11-08 12:42:28.518 o.s.w.c.s.XmlWebApplicationContext[578] - Refreshing WebApplicationContext for namespace 'dispatcher-servlet': startup date [Tue Nov 08 12:42:28 CST 2016]; parent: Root WebApplicationContext
INFO 2016-11-08 12:42:28.519 o.s.b.f.x.XmlBeanDefinitionReader[317] - Loading XML bean definitions from class path resource [spring/spring-dispatcher.xml]
INFO 2016-11-08 12:42:28.657 o.s.b.f.s.DefaultListableBeanFactory[839] - Overriding bean definition for bean 'org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping' with a different definition: replacing [Root bean: class [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping]; scope=; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null] with [Root bean: class [org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping]; scope=; abstract=false; lazyInit=false; autowireMode=0; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null]
...
INFO 2016-11-08 12:42:29.545 o.s.w.s.m.m.a.RequestMappingHandlerAdapter[532] - Looking for @ControllerAdvice: WebApplicationContext for namespace 'dispatcher-servlet': startup date [Tue Nov 08 12:42:28 CST 2016]; parent: Root WebApplicationContext
INFO 2016-11-08 12:42:29.810 o.s.w.s.v.v.VelocityConfigurer[140] - ClasspathResourceLoader with name 'springMacro' added to configured VelocityEngine
INFO 2016-11-08 12:42:30.193 o.s.w.s.DispatcherServlet[507] - FrameworkServlet 'dispatcher': initialization completed in 1684 ms
WARN 2016-11-08 12:42:30.206 o.s.w.s.PageNotFound[1136] - No mapping found for HTTP request with URI [/student/listStudent] in DispatcherServlet with name 'dispatcher'
这个错误我找了很久才发现,并不是简单的访问路径错误。仔细查看日志信息会发现spring加载dispatcher的过程,截取在web.xml中配置
<!--spring加载-->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/spring-base.xml</param-value>
</context-param>
...
<!--springMVC加载-->
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring/spring-dispatcher.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
在Tomcat启动时,web.xml中加载顺序是 context-param -> listener -> filter -> servlet,ContextLoaderListener基于Web上下文级别的监听器在启动服务器时就创建ApplicationContext并且将配置的Spring Bean加载到XML中。DispatcherServlet是一个请求分发控制器,所有匹配的URL都会通过该Servlet分发执行,在创建Servlet对象时会初始化Spring MVC相关配置。spring-dispatcher.xml中定义了控制器映射,使用Controller+RequestMapping注解映射时,相关controller组件扫描要定义在spring-dispatcher.xml中,而非spring-base.xml中。依据这样的分析,我去查看了student-test项目中spring-dispatcher.xml和spring-base.xml的配置,发现spring-base.xml配置了
<context:component-scan base-package="org.student"/>
而在spring-dispatcher.xml中未配置扫描路径。所以spring无法加载controller中的映射,自然会404了,解决方式则是在spring-dispatcher.xml中加上扫描。
博客推荐:
http://blessht.iteye.com/blog/2121845
http://www.cnblogs.com/szlbm/p/5512931.html
http://blog.csdn.net/congcong68/article/details/41113239
PS:太多朋友需要源码,可能没有及时回复邮件。现我已上传至Github,请自行下载,欢迎大家多做交流。
student-demo
student-test