spring4+springmvc+mybatis基本框架（app后台框架搭建一）

2021-09-27 15:40:43

前言：

随着spring 越来越强大，用spring4来搭建框架也是很快速，问题是你是对spring了解有多深入。如果你是新手，那么在搭建的过程中可以遇到各种各样奇葩的问题。

SSM框架的搭建是作为我搭建APP开发框架的基础。

我将会分以下几点:

1) 配置文件如何配置

2) 如何java配置启动servlet

3) 一些搭建过程中的坑

=============================================================================

配置文件如何配置

SSM框架的搭建配置方式有很多种，可具体分可以分为javaConfig配置，xml配置，或者xml文件与javaConf混合配置。其实用那种都行了，我个人搭建还是偏xml配置，不过现在的javaConfig也很成熟，也可以考虑，就是有一些坑，后面会讲到的；混合配置，用的情况也是蛮多的，分享中会涉及一点。

接下来，我主要是以java配置类做的配置：

这是项目的结构 com.ouyang.teson目录下直接放置配置类：

1）AppConfig.java

package com.ouyang.teson;

import org.mybatis.spring.mapper.MapperScannerConfigurer;

import org.springframework.context.annotation.*;

import org.springframework.transaction.annotation.EnableTransactionManagement;

import org.springframework.web.servlet.config.annotation.EnableWebMvc;

import org.springframework.web.servlet.mvc.Controller;

/**

 * Created by ThinkPad on 2017/6/15.

 */

@Configuration

@EnableAspectJAutoProxy

@EnableTransactionManagement

@ComponentScan(basePackages = {"com.ouyang.teson"},

        excludeFilters={@ComponentScan.Filter(type=FilterType.ANNOTATION,value=EnableWebMvc.class)}

)

@Import(AppDataConfig.class)

//@PropertySource({"classpath:jdbc.properties"})

//@ImportSource("XXXX.xml")

/*@Configuration，用于表示这个类是一个配置类，用于配置Spring的相关信息

@EnableAspectJAutoProxy，启用切面自动代理，用于AOP

@EnableTransactionManagement，启用注解事务，即可以使用@Transactional注解来控制事务

@ComponentScan，组件扫描，在basePackages指定的目录下扫描被@Controller、@Service、@Component等注解注册的组件

@Import，引入指定的配置类，我们引入了Spring容器配置类和数据源事务配置类

@PropertySource，加载指定的配置文件，配置文件内容会加载入Environment中等待调用*/

public class AppConfig {

    @Bean

    public MapperScannerConfigurer mapperScannerConfigurer() {

        MapperScannerConfigurer mapperScannerConfigurer = new MapperScannerConfigurer();

        // 跟@MapperScan(basePackages = { "com.ouyang.teson.dao" }) 等同

        //如果通过web.xml 加载servlet的话，可能找不到映射对象 建议用注解

        mapperScannerConfigurer.setBasePackage("com.ouyang.teson.dao");

        mapperScannerConfigurer.setSqlSessionFactoryBeanName("sqlSessionFactory");

        return mapperScannerConfigurer;

    }

}

2) AppDataConfig.java 是导入的配置

package com.ouyang.teson;

import com.alibaba.druid.pool.DruidDataSource;

import com.ouyang.teson.bean.TestBean;

import org.apache.ibatis.session.SqlSessionFactory;

import org.mybatis.spring.SqlSessionFactoryBean;

import org.mybatis.spring.SqlSessionTemplate;

import org.mybatis.spring.annotation.MapperScan;

import org.mybatis.spring.mapper.MapperScannerConfigurer;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.context.annotation.*;

import org.springframework.core.env.Environment;

import org.springframework.core.io.support.PathMatchingResourcePatternResolver;

import org.springframework.jdbc.datasource.DataSourceTransactionManager;

import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.sql.DataSource;

import java.io.IOException;

/**

 * Created by ThinkPad on 2017/6/15.

 */

@EnableAspectJAutoProxy

@EnableTransactionManagement

@PropertySource({"classpath:jdbc.properties"})

//@MapperScan(value={"/com/ouyang/teson/dao/*.xml"},basePackages = {"com.ouyang.teson.dao"})

public class AppDataConfig {

    @Autowired

    private Environment env;

    //设置阿里druid数据源

    @Bean(name="dataSource")

    public DataSource getDataSource() {

        DruidDataSource druidDataSource = new DruidDataSource();

        System.out.println("=============env============"+env.getProperty("jdbc.driverClassName"));

        druidDataSource.setDriverClassName(env.getProperty("jdbc.driverClassName"));

        druidDataSource.setUsername(env.getProperty("jdbc.username"));

        druidDataSource.setPassword(env.getProperty("jdbc.password"));

        druidDataSource.setUrl(env.getProperty("jdbc.url"));

        //连接超时时间

        druidDataSource.setMaxWait();

        //最大存活时间

        //druidDataSource.setMaxActive(10000);

        // 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

        druidDataSource.setTimeBetweenEvictionRunsMillis();

        //连接池中的最小生存时间

        druidDataSource.setMinEvictableIdleTimeMillis();

        //这里建议配置为TRUE，防止取到的连接不可用

        druidDataSource.setTestOnBorrow(true);

        druidDataSource.setTestOnReturn(false);

        //自动提交

        druidDataSource.setDefaultAutoCommit(true);

        druidDataSource.setPoolPreparedStatements(true);

        druidDataSource.setMaxPoolPreparedStatementPerConnectionSize();

        return  druidDataSource;

    }

    // 配置SqlSessionFactory对象

    public SqlSessionFactoryBean getSqSesionFactorys() throws IOException {

        SqlSessionFactoryBean sqlSessionFactoryBean =new SqlSessionFactoryBean();

        sqlSessionFactoryBean.setDataSource(getDataSource());

        // sqlSessionFactoryBean.setConfigLocation(new ClassPathResource("mybatis-config.xml")); // 这里可以通过mybatis-config.xml 来设置 typeAliasPackage和mapper。

        //这个setMapperLocations 必须把mapper文件放resources里面 不然获取文件

        //扫描mybatis配置文件的

        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();

        sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath:mapper/*.xml"));

       /*  Resource[] mapperLocations = new Resource[] { new ClassPathResource("/com/ouyang/teson/mapper*//**//*.xml") };

        sqlSessionFactoryBean.setMapperLocations(mapperLocations);*//*

       *//* Resource resource =new ClassPathResource("mybatis.xml");

        sqlSessionFactoryBean.setConfigLocation(resource);*/

        //设置映射的bean类

        sqlSessionFactoryBean.setTypeAliasesPackage("com.ouyang.teson.bean");

        return sqlSessionFactoryBean;

    }

    @Bean(name = "sqlSessionFactory")

    public SqlSessionFactory sqlSessionFactory() throws Exception {

        SqlSessionFactoryBean factoryBean = getSqSesionFactorys();

        SqlSessionFactory sqlSessionFactory = factoryBean.getObject();

        sqlSessionFactory.getConfiguration().setMapUnderscoreToCamelCase(true);// 开启驼峰映射

        sqlSessionFactory.getConfiguration().setCacheEnabled(true);

        //sqlSessionFactory.getConfiguration().setLazyLoadingEnabled(true);

        sqlSessionFactory.getConfiguration().setAggressiveLazyLoading(false);

        return sqlSessionFactory;

    }

    @Bean(name = "transactionManager")

    public DataSourceTransactionManager dataSourceTransactionManager() {

        DataSourceTransactionManager dataSourceTransactionManager = new DataSourceTransactionManager();

        dataSourceTransactionManager.setDataSource(this.getDataSource());

        return dataSourceTransactionManager;

    }

    @Bean

    @Scope("prototype")

    public SqlSessionTemplate sqlSessionTemplate() throws Exception {

        SqlSessionTemplate template =new SqlSessionTemplate(sqlSessionFactory());

        return template;

    }

}

3）webConfig.java

package com.ouyang.teson;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.ComponentScan;

import org.springframework.context.annotation.Configuration;

import org.springframework.context.annotation.FilterType;

import org.springframework.web.servlet.ViewResolver;

import org.springframework.web.servlet.config.annotation.EnableWebMvc;

import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;

import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

import org.springframework.web.servlet.mvc.Controller;

import org.springframework.web.servlet.view.InternalResourceViewResolver;

/**

 * Created by ThinkPad on 2017/6/15.

 */

@Configuration

@EnableWebMvc

@ComponentScan(basePackages = {"com.ouyang.teson"},useDefaultFilters = true)

public class WebConfig extends WebMvcConfigurerAdapter{

    private final static Logger logger = LoggerFactory.getLogger(WebConfig.class);

    public ViewResolver viewResolver() {

        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();

        viewResolver.setPrefix("/WEB-INF/views/jsp/function/");

        viewResolver.setSuffix(".jsp");

        return viewResolver;

    }

    //静态文件

    @Override

    public void addResourceHandlers(ResourceHandlerRegistry registry) {

        logger.info("addResourceHandlers");

        registry.addResourceHandler("/static/**").addResourceLocations("/WEB-INF/static/");

    }

}

SpringMvc也设置了@ComponentScan，也会去扫相应的包，useDefaultFilters = true 会自动过滤 @Component@Repository, @Service, or @Controller 一些重复的；

4) resources 配置目录下主要是两个文件：1,jdbc.properties ;2,logback.xml

以下是logback.xml,还稍微比较乱，拿其他项目的配置，顺便改了一下

<?xml version="1.0" encoding="UTF-8"?>

<configuration>

    <property name="LOG_HOME" value="D:/logs2/" />

    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">

        <encoder>

            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level [%logger{}] - %msg%n

            </pattern>

        </encoder>

    </appender>

    <appender name="FILE"

        class="ch.qos.logback.core.rolling.RollingFileAppender">

        <file>${LOG_HOME}/dts_rpc_main.log</file>

        <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">

            <!-- rollover daily -->

            <fileNamePattern>${LOG_HOME}/logbak/dts_rpc_main-%d{yyyy-MM-dd}.%i.log.zip</fileNamePattern>

            <timeBasedFileNamingAndTriggeringPolicy

                class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">

                <!-- or whenever the file size reaches 300MB -->

                <maxFileSize>1000MB</maxFileSize>

            </timeBasedFileNamingAndTriggeringPolicy>

        </rollingPolicy>

        <!-- 日志输出格式 -->

        <encoder>

            <pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{} - %msg%n  </pattern>

        </encoder>

    </appender>

    <logger name="com.ouyang.teson" level="INFO" additivity="false">

        <appender-ref ref="FILE" />

    </logger>

    <logger name="org.springframework" level="WARN" additivity="false">

        <appender-ref ref="STDOUT" />

    </logger>

    <logger name="org.springframework.boot" level="WARN" additivity="false">

        <appender-ref ref="STDOUT" />

    </logger>

    <logger name="org.mybatis" level="WARN" additivity="false">

        <appender-ref ref="STDOUT" />

    </logger>

    <logger name="org.apache" level="WARN" additivity="false">

        <appender-ref ref="STDOUT" />

    </logger>

    <logger name="com.ouyang" level="DEBUG" additivity="false">

        <appender-ref ref="STDOUT" />

    </logger>

    <logger name="com.alibaba" level="DEBUG" additivity="false">

        <appender-ref ref="STDOUT" />

    </logger>

    <root level="DEBUG">

        <appender-ref ref="STDOUT" />

    </root>

</configuration>

5） pom.xml

导入的包，都是当下最新的包

<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/maven-v4_0_0.xsd">

  <modelVersion>4.0.</modelVersion>

  <groupId>com.ouyang</groupId>

  <artifactId>Teson</artifactId>

  <packaging>war</packaging>

  <version>1.0-SNAPSHOT</version>

  <name>Teson Maven Webapp</name>

  <url>http://maven.apache.org</url>

  <properties>

    <!-- spring版本号 -->

    <spring.version>4.3..RELEASE</spring.version>

    <!-- log4j日志文件管理包版本 -->

    <slf4j.version>1.6.</slf4j.version>

    <log4j.version>1.2.</log4j.version>

    <!-- mybatis版本号 -->

    <mybatis.version>3.4.</mybatis.version>

  </properties>

  <dependencies>

    <dependency>

      <groupId>junit</groupId>

      <artifactId>junit</artifactId>

      <version>4.12</version>

      <scope>test</scope>

    </dependency>

    <!-- spring-core -->

    <dependency>

      <groupId>org.springframework</groupId>

      <artifactId>spring-core</artifactId>

      <version>${spring.version}</version>

    </dependency>

    <dependency>

      <groupId>org.springframework</groupId>

      <artifactId>spring-context</artifactId>

      <version>${spring.version}</version>

    </dependency>

    <dependency>

      <groupId>org.springframework</groupId>

      <artifactId>spring-test</artifactId>

      <version>${spring.version}</version>

    </dependency>

    <dependency>

      <groupId>org.springframework</groupId>

      <artifactId>spring-aop</artifactId>

      <version>${spring.version}</version>

    </dependency>

    <dependency>

      <groupId>org.springframework</groupId>

      <artifactId>spring-jdbc</artifactId>

      <version>${spring.version}</version>

    </dependency>

    <dependency>

      <groupId>org.springframework</groupId>

      <artifactId>spring-webmvc</artifactId>

      <version>${spring.version}</version>

    </dependency>

    <!-- AspectJ Runtime -->

    <dependency>

      <groupId>org.aspectj</groupId>

      <artifactId>aspectjrt</artifactId>

      <version>1.8.</version>

    </dependency>

    <!-- AspectJ Weaver -->

    <dependency>

      <groupId>org.aspectj</groupId>

      <artifactId>aspectjweaver</artifactId>

      <version>1.8.</version>

    </dependency>

    <!--  log 日志 -->

    <dependency>

      <groupId>org.slf4j</groupId>

      <artifactId>jcl-over-slf4j</artifactId>

      <version>1.7.</version>

    </dependency>

    <dependency>

      <groupId>ch.qos.logback</groupId>

      <artifactId>logback-classic</artifactId>

      <version>1.1.</version>

    </dependency>

    <!-- mybatis -->

    <dependency>

      <groupId>org.mybatis</groupId>

      <artifactId>mybatis</artifactId>

      <version>${mybatis.version}</version>

    </dependency>

    <dependency>

      <groupId>org.mybatis</groupId>

      <artifactId>mybatis-spring</artifactId>

      <version>1.3.</version>

    </dependency>

    <!-- mysql驱动包 -->

    <dependency>

      <groupId>mysql</groupId>

      <artifactId>mysql-connector-java</artifactId>

      <version>5.1.</version>

    </dependency>

    <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->

    <dependency>

      <groupId>com.alibaba</groupId>

      <artifactId>druid</artifactId>

      <version>1.0.</version>

    </dependency>

    <!-- https://mvnrepository.com/artifact/com.google.code.gson/gson -->

    <dependency>

      <groupId>com.google.code.gson</groupId>

      <artifactId>gson</artifactId>

      <version>2.8.</version>

    </dependency>

    <dependency>

      <groupId>junit</groupId>

      <artifactId>junit</artifactId>

      <version>RELEASE</version>

    </dependency>

    <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->

    <dependency>

      <groupId>javax.servlet</groupId>

      <artifactId>javax.servlet-api</artifactId>

      <version>3.1.</version>

      <scope>provided</scope>

    </dependency>

  </dependencies>

  <build>

    <finalName>Teson</finalName>

    <!--<build>

      <finalName>app</finalName>

    </build>-->

    <resources>

      <resource>

        <directory>src/main/java</directory>

        <includes>

          <include>**/*.xml</include>

        </includes>

        <filtering>false</filtering>

      </resource>

    </resources>

    <plugins>

      <plugin>

        <groupId>org.apache.maven.plugins</groupId>

        <artifactId>maven-compiler-plugin</artifactId>

        <version>3.5.1</version>

        <configuration>

          <source>1.8</source>

          <target>1.8</target>

          <encoding>UTF-8</encoding>

        </configuration>

      </plugin>

      <!--- 为防止 没有web.xml 情况下打包报错 -->

      <plugin>

        <groupId>org.apache.maven.plugins</groupId>

        <artifactId>maven-war-plugin</artifactId>

        <version>2.2</version>

        <configuration>

          <failOnMissingWebXml>false</failOnMissingWebXml>

        </configuration>

      </plugin>

    </plugins>

  </build>

</project>

基本的配置就这样，有基础基本都能看得懂

接下来，要说说怎么启动web服务器了

启动web服务

1）方法1

在servlet3.0之后，启动servlet，在spring里是可以直接通过java配置类进行加载servlet的。

springmvc 提供一个类AbstractAnnotationConfigDispatcherServletInitializer，该类创建了DispatcherServlet和ContextLoaderListener：getServletConfigClasses()返回的配置类定义了Spring MVC应用容器中的beans；getRootConfigClasses()返回的配置类定义了Spring应用根容器中的beans。

Spring MVC容器是根容器的子容器，子容器可以看到根容器中定义的beans，反之不行。

注意：通过AbstractAnnotationConfigDispatcherServletInitializer配置DispatcherServlet仅仅是传统的web.xml文件方式的另一个可选项。尽管你也可以使用AbstractAnnotationConfigDispatcherServletInitializer的一个子类引入web.xml文件来配置，但这没有必要。

可以参考文章：https://segmentfault.com/a/1190000004343063?_ea=575820

所以你只要自定一个类继承AbstractAnnotationConfigDispatcherServletInitializer ，你可以删掉web.xml了

webAppInitalzer.java

package com.ouyang.teson;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

/**

 * Created by ThinkPad on 2017/6/15.

 */

public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override

    protected Class<?>[] getRootConfigClasses() {

        return new Class[] { AppConfig.class };

    }

    @Override

    protected Class<?>[] getServletConfigClasses() {

        return new Class[] { WebConfig.class };

    }

    /**

     * identifies one or more paths that DispatcherServlet will be mapped to.<br>

     *  In this case, it’s mapped to /, indicating that it will be the application’s default servlet.<br>

     *   It will handle all requests coming into the application.

     */

    @Override

    protected String[] getServletMappings() {

        return new String[] { "/" };

    }

}

2) 方法2

你还是可以依然使用web.xml 来加载servlet，以下是web.xml的配置

<!DOCTYPE web-app PUBLIC

 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"

 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>

 <context-param>

   <param-name>contextClass</param-name>

   <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>

 </context-param>

  <context-param>

   <param-name>contextClassLocation</param-name>

   <param-value>com.ouyang.teson.AppConfig</param-value>

 </context-param>

    <listener>

        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>

    </listener>

    <servlet>

        <servlet-name>springServlet</servlet-name>

        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

        <init-param>

            <param-name>contextClass</param-name>

            <param-value>org.springframework.web.context.support.AnnotationConfigWebApplicationContext</param-value>

        </init-param>

        <init-param>

            <param-name>contextConfigLocations</param-name>

            <param-value>com.ouyang.teson.WebConfig</param-value>

        </init-param>

        <load-on-startup></load-on-startup>

    </servlet>

    <servlet-mapping>

        <servlet-name>springServlet</servlet-name>

        <url-pattern>/</url-pattern>

    </servlet-mapping>

  <display-name>Archetype Created Web Application</display-name>

</web-app>

一些坑的总结

1）@PropertiesSource 该注解主要是导入配置属性的，可是如果该配置类里面，如果有@bean的方法加载失败，则会直接报@PropertiesSource的属性找不到，而是定位到具体的@bean配置出现问题。

查看源码，确实很难debug代码到具体的问题，层次太深了。

2）同一个配置类，@bean的方法，在处理@bean时，是把配置加载到List集合，然后统一实例化，如果有@bean的方法是通过ContentServlet去获取bean的可能获取不到而直接报错。

ConfigurationClassParser.java 是直接加载配置类注解的主要逻辑处理，处理流程是先加载配置文件@PropertiesSource,然后处理 ComponentScans注解，加载文件，接着是处理@Import 和@importSource注解，调用processImports(configClass, sourceClass, getImports(sourceClass), true)进行处理，处理导入的配置类如果没有异常，就会把bean加载到serveltcontenx里，在主配置类就可以注入使用，如果注入不了，说明导入的配置类有问题，接着处理配置中@Bean的方法，接着processInterfaces(configClass, sourceClass)处理继承接口的默认方法。其实这个过程中，是有重复加载的，@bean的方法实例化的对象也是有重复的过程，具体怎么实现没有跟踪下去。有时间可以自己去跟踪一下代码。

3）还有一个坑，就是mybatis的配置，PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();

sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath:mapper/*.xml")); 这里配置到com.ouyang.teson.mapper 不起作用，原因是maven打包的时候不会把classpath下的xml打包进去，不过在resources下的配置文件是可以被打包进去的，所有必须把xml文件放到resources下面，才能在命名空间，映射到具体的sql。

建议：

1，配置的时候建议一步步来，不要一下配置得太多，而且一边配置，一边测试，那是最好的，避免配置太多无法一下子定位问题。

码农公寓

前言：

配置文件如何配置

启动web服务

一些坑的总结

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