SpringBoot入门系列之JPA mysql

2024-07-13 10:06:01

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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-8spring.datasource.username=rootspring.datasource.password=123456spring.datasource.driver-class-name=com.mysql.jdbc.Driverspring.jpa.hibernate.ddl-auto=updatespring.jpa.show-sql=truespring.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。在此也非常感谢大家对VeVb武林网网站的支持！