常用註解

1. @PathVariable：獲取Url中的資料
2. @RequestParam： 獲取請求引數的值
3. @GetMapping ： 組合註解，相當於@RequestMapping(method = RequestMethod.GET)
4. @PostMapping： 組合註解，相當於@RequestMapping(method = RequestMethod.POST)

5. @RestController：組合註解，相當於@Controller 加 @ResponseBody

   

## Jpa ##

• Spring-Data-Jpa定義了一系列物件持久化的標準，目前實現這一規範的產品有Hibernate,TopLink.

  pom依賴：

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.2.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
 
>
        <!--web專案必須引入的依賴-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!--單元測試-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!--Jpa-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <!--mysql附件-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--spring官方模板，跳轉指定頁面-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>

    </build>

資料庫配置：

增刪改查程式碼：
實體類 ：

package com.cym;

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

/**
 * Created by hasee
 * on 2017/4/15.
 */
@Entity    //表示當前類代表資料庫中的表
public class Girl {
    @Id
    @GeneratedValue   //自增
    private Integer id;

    private Integer age;

    public Girl() {

    }
    public Integer getId() {
        return id;
    }

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

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

介面：

package com.cym;

import org.springframework.data.jpa.repository.JpaRepository;

import java.util.List;

/**
 * Created by hasee
 * on 2017/4/15.
 */
public interface GirlPreposity extends JpaRepository<Girl,Integer>{

    //通過年齡age查詢
   public List<Girl> findByAge(Integer age);
}

Controller層（邏輯實際是寫在servicec層，這裡為了簡化）：

/**
 * Created by hasee
 * on 2017/4/15.
 */

@RestController
public class GirlController {
    @Autowired
    private GirlPreposity girlPreposity;
    /**
     *查詢所有列表
     */
    @GetMapping(value = "/girls")
    public List<Girl> findlist(){
        return girlPreposity.findAll();
    }
    /**
     *id查詢一條資料
     */
    @GetMapping(value = "/select")
    public Girl findid(@RequestParam(value = "id",defaultValue = "1") Integer id){

        return girlPreposity.findOne(id);
    }
    /**
     *age 查詢
     */
    @GetMapping(value = "/girls/age/{age}")
    public List<Girl> findlist1(@PathVariable("age") Integer age){
        return girlPreposity.findByAge(age);
    }
    /**
     *新增一條資料
     */
    @PostMapping (value= "/girls")
    public Girl add(@RequestParam(value = "age") Integer age){
        Girl girl = new Girl();
        girl.setAge(age);
        return girlPreposity.save(girl);
    }
    /**
     *更新
     */
    @PutMapping(value= "/girls/{id}")
    public Girl update(@PathVariable("id") Integer id,
                       @RequestParam(value = "age") Integer age){
        Girl girl = new Girl();
        girl.setId(id);
        girl.setAge(age);
        System.out.println(id+age);
        return girlPreposity.save(girl);
    }
    /**
     *更新
     */
    @DeleteMapping(value= "/girls/{id}")
    public void delet(@PathVariable("id") Integer id){

        girlPreposity.delete(id);
    }
}