1.開發工具:Intellij Idea,

通過JPA(Java Persistence API,Java 資料持久化介面)來操作資料庫

2.開始

2.1新建Spring Initializr 專案，勾選web,mysql,jpa依賴

專案結構如下:

2.2程式碼清單:

(1)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>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging
 
>jar</packaging>

    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version
 
>1.5.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

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

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </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>
    </build>


</project>

(2)User類程式碼：

package com.example.demo;

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

@Entity //告訴Hibernate  用這個類在資料庫中建立表
public class User {
    @javax.persistence.Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer Id;
    private String name;
    private String email;

    public void setId(Integer id) {
        Id = id;
    }

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

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

    public Integer getId() {

        return Id;
    }

    public String getName() {
        return name;
    }

    public String getEmail() {
        return email;
    }
}

(3)UserRepositroy介面程式碼：

package com.example.demo;

import org.springframework.data.repository.CrudRepository;
//繼承這個介面通過spring自動把userRepository這個物件實現為Bean
//用來對user表（對應user類自動建立的表）進行create,read,update,delete
public interface UserRepositroy extends CrudRepository<User,Long>{
}

(4)MainController類程式碼

package com.example.demo;

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

@Controller //標明此類是個控制器類
@RequestMapping(path = "/demo")// 請求地址對映為*****（伺服器地址)/demo
public class MainController {
    @Autowired
    private UserRepositroy userRepositroy;//UserRepositroy繼承了CrudRepositroy介面,所以他的物件userRepositroy會自動被pring設定為Bean，然後自動裝配
    @GetMapping(path = "/add")//請求地址對映 為*******/demo/add
    @ResponseBody //標明 方法返回的不是檢視(view)而是字串
    public String addNewUser(@RequestParam String name,@RequestParam String email){
        //@RequestParam 接受來get 或者post請求引數
        User n=new User();
        n.setName(name);
        n.setEmail(email);
        userRepositroy.save(n);
        return "Saved";
    }
    @GetMapping(path="/all")//請求地址對映 為*******/demo/all
    @ResponseBody
    public Iterable<User> getAllUsers(){
        return  userRepositroy.findAll();
    }
    @RequestMapping(path="/hello")//請求地址對映 為*******/demo/hello
    @ResponseBody
    public String helllo(){
        return "hello";
    }
}

(5)DemoApplication程式碼：

package com.example.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {

        SpringApplication.run(DemoApplication.class, args);
    }
}

(7)application.properties程式碼：

#此為專案屬性配置檔案
spring.jpa.hibernate.ddl-auto=create
spring.datasource.url=jdbc:mysql://localhost:3306/practiceDB
spring.datasource.username=資料庫賬號
spring.datasource.password=資料庫賬號的密碼

3.測試

訪問:localhost:8080/demo/hello
瀏覽器顯示：hello
瀏覽器輸入:localhost:8080/demo/add?name=Tom&[email protected]
瀏覽器顯示:saved，此時資料庫已存入資料，檢視資料庫
+—-+—————+——+
| id | email | name |
+—-+—————+——+
| 1 | [email protected] | Tom |
+—-+—————+——+
瀏覽器訪問:localhost:8080/demo/all
顯示：[{“name”:”Tom”,”email”:”[email protected]”,”id”:1}]