SpringBoot 整合 SpringData 入门案例(一)

电玩女神 2022-07-12 08:28 180阅读 0赞

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

看看两者的功能：

SpringBoot

![这里写图片描述][SouthEast]

SpringData

![这里写图片描述][SouthEast 1]

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

项目结构图：

![这里写图片描述][SouthEast 2]

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

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

![这里写图片描述][SouthEast 3]

8).在浏览器输入：[http://localhost:8080/spring/add?name=First&email=someemail@someemailprovider.com][http_localhost_8080_spring_add_name_First_email_someemail_someemailprovider.com]

数据库反向生成数据库表，也插入了数据：

![这里写图片描述][SouthEast 4]

9).在浏览器输入：[http://localhost:8080/spring/all][http_localhost_8080_spring_all]  
![这里写图片描述][SouthEast 5]

10).一个小小的整合就成功了

[SouthEast]: /images/20220710/92d4d834ed194866a55de23bc1ee77bb.png
[SouthEast 1]: /images/20220710/8e1d5d132e61474183589678808cab49.png
[SouthEast 2]: /images/20220710/b75535dd39e34c678c97a26eaeb50d52.png
[SouthEast 3]: /images/20220710/ecb485279eab470cb1991a0931ceffcd.png
[http_localhost_8080_spring_add_name_First_email_someemail_someemailprovider.com]: http://localhost:8080/spring/add?name=First&email=someemail@someemailprovider.com
[SouthEast 4]: /images/20220710/0e04558300f54e379f13ea834776b364.png
[http_localhost_8080_spring_all]: http://localhost:8080/spring/all
[SouthEast 5]: /images/20220710/92b4f4545f37441c963367eff6d94148.png