SpringBoot入门系列之JPA mysql

SpringBoot入门系列之JPA mysql

一，准备工作，建立spring-boot-sample-mysql工程

1、http://start.spring.io/

A、Artifact中输入spring-boot-sample-MySQL

     B、勾选Web下的web

     C、勾选SQL下的JPA MYSQL

2、Eclips中导入工程spring-boot-sample-mysql

A、解压快捷工程spring-boot-sample-mysql到某文件夹

B、eclips中file->import->Import Existing Maven Projects-->Select Maven projects-->finish导入工程

3、工程导入之后，文件结构如下图

4、在包com.example下建立web文件夹

5、便于测试，引入spring-boot-sample-helloworld的HelloController及配置文件logback.xml

HelloController代码为

package com.example.web;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

@RestController

public class HelloController {

protected static Logger logger=LoggerFactory.getLogger(HelloController.class);

@RequestMapping("/")

public String helloworld(){

logger.debug("访问hello");

return "Hello world!";

}

@RequestMapping("/hello/{name}")

public String helloName(@PathVariable String name){

logger.debug("访问helloName,Name={}",name);

return "Hello "+name;

}

}

logback.xml配置为

%d %p (%file:%line\)- %m%n

GBK

class="ch.qos.logback.core.rolling.RollingFileAppender">

log/base.log

log/base.log.%d.i%

64 MB

%d %p (%file:%line\)- %m%n

UTF-8

class="ch.qos.logback.core.rolling.RollingFileAppender">

log/base.log

log/base.log.%d.i%

64 MB

%d %p (%file:%line\)- %m%n

UTF-8

注：logback.xml文件位于src/main/resources下

6、启动工程，通过浏览器查看正确性

http://localhost:8080/

http://localhost:8080/hello/上帝

二，使用JPA,构建业务对象及访问库

1、在包com.example下建立domain文件夹

2、在domain中建立类Person

package com.example.domain;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

@Entity

public class Person {

@Id

@GeneratedValue

private Long id;

private String name;

private Integer age;

private String address;

public Person() {

super();

}

public Person(Long id, String name, Integer age, String address) {

super();

this.id = id;

this.name = name;

this.age = age;

this.address = address;

}

public Long getId() {

return id;

}

public void setId(Long id) {

this.id = id;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public Integer getAge() {

return age;

}

public void setAge(Integer age) {

this.age = age;

}

public String getAddress() {

return address;

}

public void setAddress(String address) {

this.address = address;

}

}

注意：构造函数

3、在包com.example下建立repository文件夹

4、在repository中建立接口PersonRepository

package com.example.repository;

import java.util.List;

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

import orghttp://.springframework.data.jpa.repository.Query;

import org.springframework.data.repository.query.Param;

import org.springframework.stereotype.Repository;

import com.example.domain.Person;

@Repository

public interface PersonRepository extends JpaRepository {

List findByName(String name);

List findByAddress(String address);

List findByNameAndAddress(String name,String address);

@Query("select p from Person p where p.name=:name and p.address=:address")

List withNameAndAddressQuery(@Param("name")String Name,@Param("address")String address);

}

5、在web中建立DataController

package com.example.web;

import java.util.List;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.data.domain.Page;

import org.springframework.data.domain.PageRequest;

import org.springframework.data.domain.Sort;

import org.springframework.data.domain.Sort.Direction;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import com.example.domain.Person;

import com.example.repository.PersonRepository;

@RestController

public class DataController {

protected static Logger logger=LoggerFactory.getLogger(DataController.class);

@Autowired

PersonRepository personRepository;

@RequestMapping("/save")

public Person save(String name,String address,Integer age){

logger.debug("save 开始");

Person p=personRepository.save(new Person(null,name,age,address));

logger.debug("save 结束");

return p;

}

@RequestMapping("/q1")

public List q1(String address){

logger.debug("q1 开始");

logger.debug("q1 接收参数address={}",address);

List people=personRepository.findByAddress(address);

return people;

}

@RequestMapping("/q2")

public List q2(String name,String address){

logger.debug("q2 开始");

logger.debug("q2接收参数name={},address={}",name,address);

return personRepository.findByNameAndAddress(name, address);

}

@RequestMapping("/q3")

public List q3(String name,String address){

logger.debug("q3 开始");

logger.debug("q3接收参数name={},address={}",name,address);

return personRepository.withNameAndAddressQuery(name, address);

}

@RequestMapping("/sort")

public List sort(){

logger.debug("sort 开始");

List people=personRepository.findAll(new Sort(Direction.ASC,"age"));

return people;

}

@RequestMapping("/page")

public Page page(){

logger.debug("page 开始");

Page people=personRepository.findAll(new PageRequest(1,2));

return people;

}

}

6、配置数据库连接，在application.properties（src/main/resources下）

spring.datasource.url=jdbc:mysql://192.168.56.201:3306/bootsample?useUnicode=true&characterEncoding=UTF-8

spring.datasource.username=root

spring.datasource.password=123456

spring.datasource.driver-class-name=com.mysql.jdbc.Driver

spring.jpa.hibernate.ddl-auto=update

spring.jpa.show-sql=true

spring.jackson.serialization.indent_output=true

7、运行测试

A、先保存数据

http://localhost:8080/save?name=aa&&address=北京&&age=1

http://localhost:8080/save?name=ab&&address=北京&&age=2

http://localhost:8080/save?name=cq1&&address=重庆&&age=50

http://localhost:8080/save?name=cq2&&address=重庆&&age=51

B、查询q1

http://localhost:8080/q1?address=北京

C、查询q2

http://localhost:8080/q2?address=北京&&name=aa

D、查询q3

http://localhost:8080/q3?address=北京&&name=aa

E、排序

http://localhost:8080/sort

F、分页

http://localhost:8080/page

运用hibernate访问mysql，基本也是老技术，只是用JPA简化了dao层代码，对于业务对象基本没有变化。

以上所述是给大家介绍的SpringBoot入门系列之JPA mysql，希望对大家有所帮助，如果大家有任何疑问请给我留言，会及时回复大家的。在此也非常感谢大家对我们网站的支持！

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