（一）SpringBoot + SpringData 入门

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J2EE的核心框架Spring！ 而SpringBoot 和SpringData大大简化了开发，使我们可以把精力专注于业务上！

1、SpringBoot

2、SpringData

环境： linux + myeclipse2015 + jdk1.7 + maven3.3.3 + SpringBoot 1.5.1+ SpringData + mysql5.5

项目结构图：

1).pom.xml

<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>4.0.0</modelVersion>
  <groupId>com.hsp.spring</groupId>
  <artifactId>SpringDataDemo</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>SpringDataDemo Maven Webapp</name>
  <url>http://maven.apache.org</url>

  <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.1.RELEASE</version>
    </parent>

  <dependencies>
  <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>3.1-b07</version>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <!-- SpringBoot 里面包含spring mvc -->
    <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!-- 引进JPA-->

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <!-- mysql连接的jar包 -->

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
  </dependencies>
  <build>
  <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    <finalName>SpringDataDemo</finalName>
  </build>
</project>

2).User.java

package hello;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

@Entity // 实体类，利用对象关系映射生成数据库表
public class User {
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Integer id;

    private String name;

    private String email;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

}

3).UserRepository.java

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package hello;

import org.springframework.data.repository.CrudRepository;

import hello.User;

// 该接口会自动被实现，springdata已经帮我们实现了基本的增删改查
// CRUD --> Create（增）, Read（查）, Update（改）, Delete（删）

public interface UserRepository extends CrudRepository<User, Long> {

}

4).MainController.java

package hello;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import hello.User;
import hello.UserRepository;

@Controller    // 表示这是一个Controller
@RequestMapping(path="/spring") // 访问url从Application/spring/开始
public class MainController {
    @Autowired//自动从spring容器中加载userRepository
    private UserRepository userRepository;

    @GetMapping(path="/add") // “/add”路径映射到addNewUser方法上
    public @ResponseBody String addNewUser (@RequestParam String name
            , @RequestParam String email) {
        // @ResponseBody 表示返回的string是一个回应（response），不是一个视图
        // @RequestParam 表示接收的参数可以是get或post

        User n = new User();
        n.setName(name);
        n.setEmail(email);
        userRepository.save(n);
        return "Saved";
    }

    @GetMapping(path="/all")
    public @ResponseBody Iterable<User> getAllUsers() {
        // 返回一个json类型的user
        return userRepository.findAll();
    }
}

5).Application.java

package hello;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        /*Spring-boot已经集成了tomcat，main函数被执行时，SpringApplication引导应用启动spring
        进而启动tomcat启动应用*/
        SpringApplication.run(Application.class, args);
    }
}

6).application.properties

spring.jpa.hibernate.ddl-auto=create
spring.datasource.url=jdbc:mysql://localhost:3306/spring
spring.datasource.username=xxxxxx
spring.datasource.password=xxxxxx

7).启动springboot

8).在浏览器输入：http://localhost:8080/spring/add?name=First&[email protected]

数据库反向生成数据库表，也插入了数据：

9).在浏览器输入：http://localhost:8080/spring/all 

10).整合就成功了