Spring Boot快速入门

使用Spring Boot快速搭建一个Web应用

环境准备

• Intellij idea
• Maven
• Java环境

官网入门

http://projects.spring.io/spring-boot/
根据这个搭建最简单的应用
pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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>org.georgejiang</groupId>
    <artifactId>springboot-web-demo</artifactId>
    <version>0.1.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
    </parent>
    <dependencies>
        <!--<dependency>-->
            <!--<groupId>org.springframework.boot</groupId>-->
            <!--<artifactId>spring-boot-starter-web</artifactId>-->
            这个jar被thymeleaf所包括，所以注释了以省略
        <!--</dependency>-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

    </dependencies>

</project>

接下来创建src/main/application/Application.java

package application;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@EnableAutoConfiguration
@ComponentScan(basePackages = {"hello", "lullaby"})
public class Application {

    public static void main(String[] args) throws Exception {
        SpringApplication.run(Application.class, args);
    }
}

• SpringApplication是Spring Boot框架中描述Spring应用的类，它的run()方法会创建一个Spring应用上下文（Application Context）。另一方面它会扫描当前应用类路径上的依赖，例如本例中发现spring-webmvc（由 spring-boot-starter-web传递引入）在类路径中，那么Spring Boot会判断这是一个Web应用，并启动一个内嵌的Servlet容器（默认是Tomcat）用于处理HTTP请求。

• Spring WebMvc框架会将Servlet容器里收到的HTTP请求根据路径分发给对应的@Controller类进行处理，@RestController是一类特殊的@Controller，它的返回值直接作为HTTP Response的Body部分返回给浏览器。

• @RequestMapping注解表明该方法处理那些URL对应的HTTP请求，也就是我们常说的URL路由（routing)，请求的分发工作是有Spring完成的。例如上面的代码中http://localhost:8080/根路径就被路由至home方法进行处理。如果访问http://localhost:8080/hello，则会出现404 Not Found错误，因为我们并没有编写任何方法来处理/hello请求。

创建src/main/hello/SampleController.java

package hello;

import org.springframework.boot.*;
import org.springframework.boot.autoconfigure.*;
import org.springframework.stereotype.*;
import org.springframework.web.bind.annotation.*;

@RestController //@Controller
@EnableAutoConfiguration
@RequestMapping("/")
public class SampleController {

    @RequestMapping("/")
//    @ResponseBody
    String home() {
        return "Hey dude, Hello World!";
    }

    @RequestMapping("/hola")
//    @ResponseBody
    public String hola() {
        return "Hola, senor!";
    }
    @RequestMapping("/users/{username}")
    public String userProfile(@PathVariable("username") String username) {
        return String.format("user %s", username);
    }

    @RequestMapping("/posts/{id}")
    public String post(@PathVariable("id") int id) {
        return String.format("post %d", id);
    }

    @RequestMapping(value = "/login", method = RequestMethod.GET)
    public String loginGet() {
        return "Login Page";
    }

    @RequestMapping(value = "/login", method = RequestMethod.POST)
    public String loginPost() {
        return "Login Post Request";
    }

    public static void main(String[] args) throws Exception {
        SpringApplication.run(SampleController.class, args);
    }
}

创建src/main/hello/HelloController.java

package hello;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/hello")
public class HelloController {

    @RequestMapping("/{name}")
    public String hello(@PathVariable("name") String name, Model model) {
        model.addAttribute("name", name);
        return "hello";
    }
}

创建src/main/lullaby/LullabyController.java

package lullaby;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@EnableAutoConfiguration
@RequestMapping("/lullaby")
public class LullabyController {

    @RequestMapping("/dude")
    @ResponseBody
    String home() {
        return "Hey dude, Hello World!";
    }

    @RequestMapping("/hola")
    public String hola() {
        return "Hola, senor!";
    }

    public static void main(String[] args) throws Exception {
        SpringApplication.run(LullabyController.class, args);
    }
}

附录：
http://blog.csdn.net/xiaoyu411502/article/details/47864969