SpringBoot入门系列：第五篇 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
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;
}
}
%d %p (%file:%line\)- %m%n
GBK
log/base.log
log/base.log.%d.i%
64 MB
%d %p (%file:%line\)- %m%n
UTF-8
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;
}
}
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 org.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);
}
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;
}
}
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。