SpringBoot入门示例

SpringBoot入门Demo

SpringBoot可以说是Spring的简化版。配置简单、使用方便。主要有以下几种特点:

  1. 创建独立的Spring应用程序
  2. 嵌入的Tomcat,无需部署WAR文件
  3. 简化Maven配置
  4. 自动配置Spring
  5. 提供生产就绪型功能,如指标,健康检查和外部配置
  6. 绝对没有代码生成和对XML没有要求配置

(1)创建maven项目,构建java项目(注意:这里为java项目,也能通过内嵌的tomcat启动服务,访问controller指定路径返回的数据)

  项目目录结构如下:

(需要编写的只有三个文件:User.java   UserController.java  pom.xml)

  SpringBoot入门示例

(2)User.java内容如下:(User.java主要是用于controller类请求方法中需要使用到User实体类)

package SpringBootDemo;

public class User {

    private int id;
private String username;
private String password; public User(){} public int getId() {
return id;
} public void setId(int id) {
this.id = id;
} public String getUsername() {
return username;
} public void setUsername(String username) {
this.username = username;
} public String getPassword() {
return password;
} public void setPassword(String password) {
this.password = password;
} public String toString(){
return "user=[id:"+id+",username:"+username+",password:"+password+"]";
}
}

(3)UserController类内容如下:(UserController相当于Spring的controller类,这里是使用@RestController注解标识,表示直接返回数据)

@RestController注解,相当于@Controller+@ResponseBody两个注解的结合,返回json数据不需要在方法前面加@ResponseBody注解了,但使用@RestController这个注解,就不能返回jsp,html页面,视图解析器无法解析jsp,html页面

@EnableAutoConfiguration :自动配置 这个注解应该放在SpringBoot项目的启动类的上面 (含有main方法,并且调用了SpringApplication.run(类.class);方法)

@SpringBootApplication : 标明这是SpringBoot的启动类

package SpringBootDemo;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController; /**
* controller类
* @author Administrator
*
*/
@RestController
@EnableAutoConfiguration
@SpringBootApplication
public class UserController { @RequestMapping("/login")
public User login(){
User user= new User();
user.setId(123);
user.setUsername("qwe");
user.setPassword("456");
return user;
} @RequestMapping("/print")
public String print1(){
return "HELLO WORLD";
}

  //这是springBoot的启动入口方法,也可以去新建一个类 ,在类里面调用SpringApplication.run(UserController.class);
public static void main(String[] args){
SpringApplication.run(UserController.class);
}
}

(4)pom.xml文件的配置如下:里面需要添加springBoot的包依赖

<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>springboot.maven</groupId>
<artifactId>springboot</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>springboot</name>
<url>http://maven.apache.org</url> <build>
<finalName>springboot</finalName>
<plugins>
<plugin>
<inherited>true</inherited>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>${compiler.source}</source>
<target>${compiler.target}</target>
<encoding>${project.build.sourceEncoding}</encoding>
</configuration>
</plugin> <plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>1.5.1.RELEASE</version> </plugin> </plugins>
</build>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<compiler.source>1.7</compiler.source>
<compiler.target>1.7</compiler.target>
<junit.version>4.12</junit.version>
</properties> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.1.RELEASE</version>
</parent> <dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
</project>
<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>springboot.maven</groupId>
<artifactId>springboot</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>springboot</name>
<url>http://maven.apache.org</url> <build>
<finalName>springboot</finalName>
<plugins>
<plugin>
<inherited>true</inherited>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>${compiler.source}</source>
<target>${compiler.target}</target>
<encoding>${project.build.sourceEncoding}</encoding>
</configuration>
</plugin> <plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>1.5.1.RELEASE</version> </plugin> </plugins>
</build>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<compiler.source>1.7</compiler.source>
<compiler.target>1.7</compiler.target>
<junit.version>4.12</junit.version>
</properties> <parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.1.RELEASE</version>
</parent> <dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency> <dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
</project>

(5)启动项目。

  进入 UserController类中,右击 --》选择 Run As   --》 Java Application

启动成功后,会出现如图结果:

SpringBoot入门示例

出现了 Started UserController。。。  这句话,标识启动成功,然后就可以去浏览器访问了

(6)访问项目

由于没有编写配置文件,所有以访问SpringBoot项目,默认是省略项目名的,直接使用 http://ip:port/RequestMapping对应的路径

例如本例: http://127.0.0.1:8080/login

就会出现如下结果,如图所示:

SpringBoot入门示例

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