SpringBoot入门系列之JPA mysql

一，准备工作，建立spring-boot-sample-mysql工程

1、

     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

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

=北京&&age=1
=北京&&age=2
=重庆&&age=50
=重庆&&age=51

b、查询q1

=北京

c、查询q2

=北京&&name=aa

d、查询q3

=北京&&name=aa

e、排序

f、分页

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