SpringBoot使用JPA

Spring Data JPA 是 Spring 基于 ORM 框架、JPA 规范的基础上封装的一套JPA应用框架，可使开发者用极简的代码即可实现对数据的访问和操作。它提供了包括增删改查等在内的常用功能，且易于扩展！学习并使用 Spring Data JPA 可以极大提高开发效率！

项目结构：

添加依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!-- MYSQL -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

application.properties

#datasource
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql:///test?useUnicode=true&characterEncoding=UTF-8
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.tomcat.max-active=20
spring.datasource.tomcat.test-while-idle=true
spring.datasource.tomcat.validation-query=select 1
spring.datasource.tomcat.default-auto-commit=false
spring.datasource.tomcat.min-idle=15
spring.datasource.tomcat.initial-size=15
#jpa
spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true
spring.jackson.serialization.indent-output=true

User.java

package com.dx.eintity;

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

/**
 * 
 * @ClassName: User
 * @Description:实体User
 * @author: dongxiang
 * @date: 2018年1月25日 上午11:30:35
 * @version V1.0
 */
@Entity
@Table(name = "sys_user")
public class User {
    public User() {
    }
    public User(String name, String password) {
        this.name = name;
        this.password = password;
    }
    private int id;
    private String name;
    private String password;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    @Column(name = "name")
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Column(name = "password")
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    @Override
    public String toString() {
        return "User{" + "userId=" + id + ", username='" + name + '\''
                + ", userpwd='" + password + '\'' + '}';
    }
}

UserDao.java

package com.dx.dao;

import java.util.List;

import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Service;

import com.dx.eintity.User;

@Service
public interface UserDao extends JpaRepository<User, Integer> {

    User findByName(String name);

    List<User> findByNameContaining(String name);

    Page<User> findByNameNot(String name,Pageable pageable); 
}

MainController.java

package com.dx.controller;

import java.util.Iterator;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.dx.dao.UserDao;
import com.dx.eintity.User;

/**
 * 
 * @ClassName: MainController
 * @Description:请求处理
 * @author: dongxiang
 * @date: 2018年1月25日 上午11:37:17
 * @version V1.0
 */
@RestController
public class MainController {
    @Autowired
    UserDao userDao;
    /**
     * 
     * @Title: getUser
     * @Description:获取用户
     * @param: @param id
     * @param: @return
     * @return: User
     * @throws
     */
    @RequestMapping("/getUser")
    public User getUser(String name) {
        return userDao.findByName(name);
    }
    /**
     * 
     * @Title: getUsersByName
     * @Description: 根据姓名查询
     * @param: @param name
     * @param: @return
     * @return: List<User>
     * @throws
     */
    @RequestMapping("/getUsersByName")
    public List<User> getUsersByName(String name) {
        return userDao.findByNameContaining(name);
    }
    @RequestMapping("/getPageUser")
    public Page<User> getPageUser(String name) {
        Sort sort = new Sort(Sort.Direction.DESC, "id");// 排序
        int page = 1;// 第几页
        int size = 5;// 每页多少条
        Pageable pageable = new PageRequest(page, size, sort);
        Page<User> pages = userDao.findByNameNot(name, pageable);
        Iterator<User> it = pages.iterator();
        while (it.hasNext()) {
            System.out.println("value:" + ((User) it.next()).getName());
        }
        return userDao.findByNameNot(name, pageable);
    }
    @RequestMapping("/addUser")
    public String addUser() {
        User u = new User("vvv", "vvvvvv");
        userDao.save(u);
        return "添加成功！";
    }
}

启动项目，测试结果：