SpringBoot入门系列之JPA mysql
- 作者: Mars符号
- 来源: 51数据库
- 2020-08-07
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
<configuration> <!-- %m输出的信息,%p日志级别,%t线程名,%d日期,%c类的全名,,,, --> <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender"> <encoder> <pattern>%d %p (%file:%line\)- %m%n</pattern> <charset>GBK</charset> </encoder> </appender> <appender name="baselog" class="ch.qos.logback.core.rolling.RollingFileAppender"> <File>log/base.log</File> <rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy"> <fileNamePattern>log/base.log.%d.i%</fileNamePattern> <timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP"> <!-- or whenever the file size reaches 64 MB --> <maxFileSize>64 MB</maxFileSize> </timeBasedFileNamingAndTriggeringPolicy> </rollingPolicy> <encoder> <pattern> %d %p (%file:%line\)- %m%n </pattern> <charset>UTF-8</charset> <!-- 此处设置字符集 --> </encoder> </appender> <root level="info"> <appender-ref ref="STDOUT" /> </root> <logger name="com.example" level="DEBUG"> <appender-ref ref="baselog" /> </logger> </configuration>
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 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<Person,Long> { List<Person> findByName(String name); List<Person> findByAddress(String address); List<Person> findByNameAndAddress(String name,String address); @Query("select p from Person p where p.name=:name and p.address=:address") List<Person> 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<Person> q1(String address){ logger.debug("q1 开始"); logger.debug("q1 接收参数address={}",address); List<Person> people=personRepository.findByAddress(address); return people; } @RequestMapping("/q2") public List<Person> 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<Person> 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<Person> sort(){ logger.debug("sort 开始"); List<Person> people=personRepository.findAll(new Sort(Direction.ASC,"age")); return people; } @RequestMapping("/page") public Page<Person> page(){ logger.debug("page 开始"); Page<Person> 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。
以上所述是小编给大家介绍的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,小编会及时回复大家的。