springdata-jpa 八种查询方法

使用：maven+Spring+jpa+Junit4

查询方式：SQL，JPQL查询，Specification多条件复杂查询

返回类型：list<POJO>,list<Stinrg>,list<Object>,Page<Object>

git源码地址：https://github.com/litblank/SpringFrame/tree/master/DEMO/SpringData_jpa

1. Pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.litblack</groupId>
  <artifactId>SpringData_jpa</artifactId>
  <packaging>war</packaging>
  <version>0.0.1-SNAPSHOT</version>
  <name>SpringData_jpa Maven Webapp</name>
  <url>http://maven.apache.org</url>
  <properties>
        <spring.version>4.3.4.RELEASE</spring.version>
  </properties>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <!-- jpa -->        
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>4.3.8.Final</version>
             <exclusions>
                <exclusion>
                    <groupId>org.javassist</groupId>
                    <artifactId>javassist</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- <dependency>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.0-api</artifactId>
            <version>1.0.1.Final</version>
        </dependency> -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
            <version>4.3.11.Final</version>
            <exclusions>
                <exclusion>
                    <groupId>org.javassist</groupId>
                    <artifactId>javassist</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- oracle -->
        <dependency>
            <groupId>ojdbc</groupId>
            <artifactId>ojdbc6</artifactId>
            <version>11.2.0.4</version>
        </dependency>
        <!-- mysql  -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
        <!-- ali 数据源连接 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.31</version>
        </dependency>
    &lt;dependency&gt;
        &lt;groupId&gt;javassist&lt;/groupId&gt;
        &lt;artifactId&gt;javassist&lt;/artifactId&gt;
        &lt;version&gt;3.12.1.GA&lt;/version&gt;
    &lt;/dependency&gt;
    
    &lt;!-- Test --&gt;
    &lt;dependency&gt;
        &lt;groupId&gt;org.springframework&lt;/groupId&gt;
        &lt;artifactId&gt;spring-test&lt;/artifactId&gt;
        &lt;version&gt;${spring.version}&lt;/version&gt;
        &lt;scope&gt;test&lt;/scope&gt;
    &lt;/dependency&gt;
    &lt;dependency&gt;
        &lt;groupId&gt;junit&lt;/groupId&gt;
        &lt;artifactId&gt;junit&lt;/artifactId&gt;
        &lt;version&gt;4.12&lt;/version&gt;
    &lt;/dependency&gt;
    
    &lt;dependency&gt;
        &lt;groupId&gt;org.springframework&lt;/groupId&gt;
        &lt;artifactId&gt;spring-context&lt;/artifactId&gt;
        &lt;version&gt;${spring.version}&lt;/version&gt;
    &lt;/dependency&gt;
    &lt;dependency&gt;
        &lt;groupId&gt;org.springframework&lt;/groupId&gt;
        &lt;artifactId&gt;spring-oxm&lt;/artifactId&gt;
        &lt;version&gt;${spring.version}&lt;/version&gt;
    &lt;/dependency&gt;
    &lt;dependency&gt;
        &lt;groupId&gt;org.springframework&lt;/groupId&gt;
        &lt;artifactId&gt;spring-orm&lt;/artifactId&gt;
        &lt;version&gt;${spring.version}&lt;/version&gt;
    &lt;/dependency&gt;
    
    &lt;!-- springdata --&gt;
    &lt;dependency&gt;
        &lt;groupId&gt;org.springframework.data&lt;/groupId&gt;
        &lt;artifactId&gt;spring-data-jpa&lt;/artifactId&gt;
        &lt;version&gt;1.11.1.RELEASE&lt;/version&gt;
    &lt;/dependency&gt;
    &lt;dependency&gt;
        &lt;groupId&gt;org.springframework.data&lt;/groupId&gt;
        &lt;artifactId&gt;spring-data-commons-core&lt;/artifactId&gt;
        &lt;version&gt;1.4.1.RELEASE&lt;/version&gt;
    &lt;/dependency&gt;

</dependencies>

<build>

<finalName>SpringData_jpa</finalName>

</build>

</project>

pom.xml

2. Spring-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:p="http://www.springframework.org/schema/p" xmlns:cache="http://www.springframework.org/schema/cache"
    xmlns:jpa="http://www.springframework.org/schema/data/jpa"
xsi:schemaLocation</span>="http://www.springframework.org/schema/beans   
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/beans/spring-beans-3.1.xsd   </span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/context   </span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/context/spring-context-3.1.xsd   </span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/aop   </span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/aop/spring-aop-3.1.xsd   </span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/tx    </span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/tx/spring-tx-3.1.xsd</span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/cache </span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/cache/spring-cache-3.1.xsd</span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/data/jpa</span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/data/jpa/spring-jpa.xsd</span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/data/repository</span>
      http:<span style="color: #008000;">//</span><span style="color: #008000;">www.springframework.org/schema/data/repository/spring-repository-1.5.xsd"&gt;  </span>
&lt;context:component-scan base-<span style="color: #0000ff;">package</span>="com.litblack.jpa"&gt;&lt;/context:component-scan&gt;
                                      
&lt;!-- 配置Spring Data JPA扫描目录, repository 包 --&gt;
&lt;jpa:repositories base-<span style="color: #0000ff;">package</span>="com.litblack.jpa" /&gt; 

&lt;!-- 定义实体管理器工厂 --&gt;
&lt;bean id="entityManagerFactory" <span style="color: #0000ff;">class</span>="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"&gt;
    &lt;property name="dataSource" ref="dataSource" /&gt;
    &lt;!-- 扫描pojo --&gt;
    &lt;property name="packagesToScan" value="com.litblack.jpa" /&gt;
    &lt;property name="persistenceProvider"&gt;
        &lt;bean <span style="color: #0000ff;">class</span>="org.hibernate.ejb.HibernatePersistence" /&gt;
    &lt;/property&gt;
    &lt;property name="jpaVendorAdapter"&gt;
        &lt;bean <span style="color: #0000ff;">class</span>="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"&gt;
            &lt;property name="generateDdl" value="true" /&gt;
               &lt;property name="database" value="MYSQL" /&gt;
            &lt;!-- &lt;property name="database" value="ORACLE" /&gt;  --&gt;
            &lt;!-- &lt;property name="databasePlatform" value="org.hibernate.dialect.MySQL5InnoDBDialect" /&gt; --&gt;
            &lt;property name="showSql" value="true" /&gt;
        &lt;/bean&gt;
    &lt;/property&gt;
    &lt;property name="jpaDialect"&gt;
        &lt;bean <span style="color: #0000ff;">class</span>="org.springframework.orm.jpa.vendor.HibernateJpaDialect" /&gt;
    &lt;/property&gt;
    &lt;property name="jpaPropertyMap"&gt;
        &lt;map&gt;
            &lt;entry key="hibernate.generate_statistics" value="false" /&gt;&lt;!-- 关闭打印的日志 --&gt;
            &lt;entry key="hibernate.query.substitutions" value="true 1, false 0" /&gt;
            &lt;entry key="hibernate.default_batch_fetch_size" value="16" /&gt;
            &lt;entry key="hibernate.max_fetch_depth" value="2" /&gt;
            &lt;entry key="hibernate.bytecode.use_reflection_optimizer" value="true" /&gt;
            &lt;entry key="hibernate.cache.use_second_level_cache" value="false" /&gt;
            &lt;entry key="hibernate.cache.use_query_cache" value="false" /&gt;
        &lt;/map&gt;
    &lt;/property&gt;
&lt;/bean&gt;

&lt;!-- 数据源 --&gt;
&lt;bean id="dataSource" <span style="color: #0000ff;">class</span>="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"&gt;
    &lt;property name="driverClassName" value="com.mysql.jdbc.Driver" /&gt;
    &lt;property name="url" value="jdbc:mysql://localhost:3306/cyd?useUnicode=true&amp;amp;characterEncoding=UTF-8" /&gt;
    &lt;property name="username" value="root" /&gt;
    &lt;property name="password" value="root" /&gt;
&lt;/bean&gt;
&lt;!-- 配置事务管理器 --&gt;
&lt;bean id="transactionManager" <span style="color: #0000ff;">class</span>="org.springframework.orm.jpa.JpaTransactionManager"&gt;
    &lt;property name="entityManagerFactory" ref="entityManagerFactory" /&gt;
&lt;/bean&gt;

&lt;!-- 启用 annotation事务 --&gt;
&lt;tx:annotation-driven transaction-manager="transactionManager" /&gt;

</beans>

Spring-config.xml

3. UserBean.java

package com.litblack.jpa;
import java.util.Date;
import javax.persistence.Column;

import javax.persistence.Entity;

import javax.persistence.GeneratedValue;

import javax.persistence.Id;

import javax.persistence.Table;
import org.hibernate.annotations.GenericGenerator;

import org.springframework.stereotype.Component;
@Table(name = "cyd_sys_user")

@Entity

public class UserBean {
@Id
@GeneratedValue(generator </span>= "system_uuid"<span style="color: #000000;">)
@GenericGenerator(name </span>= "system_uuid", strategy = "uuid"<span style="color: #000000;">)
</span><span style="color: #0000ff;">private</span><span style="color: #000000;"> String id;
@Column(name</span>="user_name"<span style="color: #000000;">)
</span><span style="color: #0000ff;">private</span><span style="color: #000000;"> String userName;
@Column(name</span>="create_time"<span style="color: #000000;">)
</span><span style="color: #0000ff;">private</span><span style="color: #000000;"> Date createTime;

</span><span style="color: #0000ff;">public</span><span style="color: #000000;"> String getId() {
    </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> id;
}

</span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> setId(String id) {
    </span><span style="color: #0000ff;">this</span>.id =<span style="color: #000000;"> id;
}

</span><span style="color: #0000ff;">public</span><span style="color: #000000;"> String getUserName() {
    </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> userName;
}

</span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> setUserName(String userName) {
    </span><span style="color: #0000ff;">this</span>.userName =<span style="color: #000000;"> userName;
}

</span><span style="color: #0000ff;">public</span><span style="color: #000000;"> Date getCreateTime() {
    </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> createTime;
}

</span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> setCreateTime(Date createTime) {
    </span><span style="color: #0000ff;">this</span>.createTime =<span style="color: #000000;"> createTime;
}

@Override
</span><span style="color: #0000ff;">public</span><span style="color: #000000;"> String toString() {
    </span><span style="color: #0000ff;">return</span> "UserBean [id=" + id + ", userName=" + userName + ", createTime=" + createTime + "]"<span style="color: #000000;">;
}

}

POJO

4. UserBeanRepository.java

package com.litblack.jpa;
import java.util.List;

import java.util.Map;
import org.springframework.data.domain.Page;

import org.springframework.data.domain.Pageable;

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

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

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

/**


SQL，JPQL查询


返回：list<POJO>,list<Stinrg>,list<Object>,Page<Object>


不能返回MAP


@author chenyd


2018年1月10日

*/

public interface UserBeanRepository  extends JpaRepository<UserBean, Long>, JpaSpecificationExecutor<UserBean>{
UserBean findByUserName(String username);
@Query("from UserBean where userName =?1")

List<UserBean> find_Jpql_list_obj(String username);
@Query("select userName from UserBean where userName =?1")

List<String> find_Jpql_list_one(String username);
@Query("select userName,createTime from UserBean where userName =?1")

List<Object> find_Jpql_list_morefield(String username);
@Query("select userName,createTime from UserBean ")

List<Object> find_Jpql_list_pojo_morefield();
/**

若返回类型为POJO，必须是所有POJO的所有字段，不能只查询某个字段

*/

@Query(value="select * from cyd_sys_user",nativeQuery=true)

List<UserBean> find_SQL_pojo();

@Query(value="select user_name,name from cyd_sys_user,t_user",nativeQuery=true)

List<Object> find_SQL_obj();

　　@Query(value = "select new map(userName,createTime) from UserBean")
    List<Map<String,Object>> find_SQL_obj_map();
/**

分页需要 #pageable 标识
NativeJpaQuery
@param pageable
@return

/

@Query(value="select user_name,name from cyd_sys_user,t_user  /#pageable/  ",countQuery="select count() from cyd_sys_user,t_user",nativeQuery=true)

Page<Object> find_SQL_obj(Pageable pageable);

}

5. BaseJunit4Test.java

package com.litblack.jpa;
import java.util.Date;

import java.util.List;

import java.util.Map;
import javax.persistence.criteria.CriteriaBuilder;

import javax.persistence.criteria.CriteriaQuery;

import javax.persistence.criteria.Expression;

import javax.persistence.criteria.Order;

import javax.persistence.criteria.Predicate;

import javax.persistence.criteria.Root;
import org.junit.Test;

import org.junit.runner.RunWith;

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

import org.springframework.data.domain.Page;

import org.springframework.data.domain.PageRequest;

import org.springframework.data.domain.Pageable;

import org.springframework.data.domain.Sort;

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

import org.springframework.data.jpa.domain.Specification;

import org.springframework.test.context.ContextConfiguration;

import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
@RunWith(SpringJUnit4ClassRunner.class)

@ContextConfiguration(locations = { "classpath*:/spring-config.xml" })

public class BaseJunit4Test {
@Autowired
</span><span style="color: #0000ff;">private</span><span style="color: #000000;"> UserBeanRepository userRepository;

</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * 保存
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> save_obj() {
    System.out.println(userRepository);
    </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; 100; i++<span style="color: #000000;">) {
        UserBean entity </span>= <span style="color: #0000ff;">new</span><span style="color: #000000;"> UserBean();
        entity.setUserName(</span>"user_" +<span style="color: #000000;"> i);
        entity.setCreateTime(</span><span style="color: #0000ff;">new</span><span style="color: #000000;"> Date());
        userRepository.save(entity);
    }

}
</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * 查询-所有
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> get_ALL_obj(){
    List</span>&lt;UserBean&gt; list=<span style="color: #000000;">userRepository.findAll();
    </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; list.size(); i++<span style="color: #000000;">) {
        UserBean obj </span>=<span style="color: #000000;"> list.get(i);
        System.out.println(obj.getCreateTime());
    }
}
</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * 查询-one-obj,自定义接口
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> get_one_obj(){
    UserBean obj </span>= userRepository.findByUserName("user_1"<span style="color: #000000;">);
    System.out.println(obj.toString());
}
</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * 根据JQPL查询，获取一个包含所有字段的OBJ
 * 返回: 一个pojo 集合
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> get_jqpl_obj(){
    List</span>&lt;UserBean&gt; list=userRepository.find_Jpql_list_obj("user_2"<span style="color: #000000;">);
    </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; list.size(); i++<span style="color: #000000;">) {
        UserBean obj </span>=<span style="color: #000000;"> list.get(i);
        System.out.println(obj.toString());
    }
}
</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * 根据JQPL查询,获取一个字段，
 * 返回：一个字段
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> get_jqpl_onestr(){
    List</span>&lt;String&gt; list=userRepository.find_Jpql_list_one("user_2"<span style="color: #000000;">);
    </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; list.size(); i++<span style="color: #000000;">) {
        String obj </span>=<span style="color: #000000;"> list.get(i);
        System.out.println(obj.toString());
    }
}
</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * 根据JQPL查询,一行数据，获取多个字段
 * 返回：object 不是POJO,不是string[]。是Object[] 
 * 注意：每个数据类型与POJO类型一致
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> get_jqpl_morestr(){
    List</span>&lt;Object&gt; list=userRepository.find_Jpql_list_morefield("user_2"<span style="color: #000000;">);
    </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; list.size(); i++<span style="color: #000000;">) {
        Object[] obj </span>=<span style="color: #000000;"> (Object[]) list.get(i);
        String username</span>=(String) obj[0<span style="color: #000000;">];
        Date date</span>=(Date) obj[1<span style="color: #000000;">];
        System.out.println(username</span>+"	"+<span style="color: #000000;">date);
    }
}
</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * JQPL  获取指定字段的多个POJO
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> get_jqpl_pojo_morestr(){
    List</span>&lt;Object&gt; list=<span style="color: #000000;">userRepository.find_Jpql_list_pojo_morefield();
    </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; list.size(); i++<span style="color: #000000;">) {
        Object[] obj </span>=<span style="color: #000000;"> (Object[]) list.get(i);
        String username</span>=(String) obj[0<span style="color: #000000;">];
        Date date</span>=(Date) obj[1<span style="color: #000000;">];
        System.out.println(username</span>+"	"+<span style="color: #000000;">date);
    }
}
</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * SQL  获取POJO的所有字段，必须是所有POJO的所有字段
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> get_sql_pojo_allstr(){
    List</span>&lt;UserBean&gt; list=<span style="color: #000000;">userRepository.find_SQL_pojo();
    </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; list.size(); i++<span style="color: #000000;">) {
        UserBean obj </span>=<span style="color: #000000;"> list.get(i);
        System.out.println(obj.toString());
    }
}
</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * SQL  获取多表查询的字段,可用于多表查询，组成临时表
 * 注意：每个数据类型与POJO类型一致
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> get_sql_obj_morestr(){
    List</span>&lt;Object&gt; list=<span style="color: #000000;">userRepository.find_SQL_obj();
    </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; list.size(); i++<span style="color: #000000;">) {
        Object[] obj </span>=<span style="color: #000000;"> (Object[]) list.get(i);
        String username</span>=(String) obj[0<span style="color: #000000;">];
        String name</span>=(String) obj[1<span style="color: #000000;">];
        System.out.println(username</span>+"	"+<span style="color: #000000;">name);
    }
}<br>/**<br>&nbsp;&nbsp; &nbsp; * Hql 能返回list&lt;Map&gt;<br>&nbsp;&nbsp; &nbsp; */<br>&nbsp;&nbsp; &nbsp;@Test<br>&nbsp;&nbsp; &nbsp;public void get_sql_obj_morestr1(){<br>&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;List&lt;Map&lt;String,Object&gt;&gt; list=userRepository.find_SQL_obj_map();<br>&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;for (int i = 0; i &lt; list.size(); i++) {<br>&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;Map&lt;String,Object&gt; obj = list.get(i);<br>&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;System.out.println(obj);<br>&nbsp;&nbsp; &nbsp;&nbsp;&nbsp; &nbsp;}<br>&nbsp;&nbsp; &nbsp;}
</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * 分页查询,先排序后分页
 * select user_name,name from cyd_sys_user,t_user order by user_name desc limit ?, ?
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> get_sql_obj_morestr_page(){
    Sort sort</span>=<span style="color: #0000ff;">new</span> Sort(Direction.DESC,"user_name"<span style="color: #000000;">);
    Pageable page</span>=<span style="color: #0000ff;">new</span> PageRequest(2,10,sort);<span style="color: #008000;">//</span><span style="color: #008000;">第二页，每页10条</span>
    Page&lt;Object&gt; p=<span style="color: #000000;">userRepository.find_SQL_obj(page);
    List</span>&lt;Object&gt; list=<span style="color: #000000;">p.getContent();
    </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; list.size(); i++<span style="color: #000000;">) {
        Object[] obj </span>=<span style="color: #000000;"> (Object[]) list.get(i);
        String username</span>=(String) obj[0<span style="color: #000000;">];
        String name</span>=(String) obj[1<span style="color: #000000;">];
        System.out.println(username</span>+"	"+<span style="color: #000000;">name);
    }
}
</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * 多条件查询,分页,排序
 </span><span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> get_sql_obj_morestr_(){
    Page</span>&lt;UserBean&gt; p=userRepository.findAll(<span style="color: #0000ff;">new</span> Specification&lt;UserBean&gt;<span style="color: #000000;">() {
        
        </span><span style="color: #0000ff;">public</span> Predicate toPredicate(Root&lt;UserBean&gt; root, CriteriaQuery&lt;?&gt;<span style="color: #000000;"> query, CriteriaBuilder cb) {
            Predicate stuNameLike </span>= cb.like(root.&lt;String&gt; get("userName"), "%user_%"<span style="color: #000000;">);
            Order oderby </span>=cb.desc(root.&lt;String&gt; get("userName"<span style="color: #000000;">));
            </span><span style="color: #0000ff;">if</span>(<span style="color: #0000ff;">null</span> !=<span style="color: #000000;"> stuNameLike) query.where(stuNameLike);
            query.orderBy(oderby);
            </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> stuNameLike;
        }
    },</span><span style="color: #0000ff;">new</span> PageRequest(0, 20<span style="color: #000000;">));
    List</span>&lt;UserBean&gt; list=<span style="color: #000000;">p.getContent();
    </span><span style="color: #0000ff;">for</span> (<span style="color: #0000ff;">int</span> i = 0; i &lt; list.size(); i++<span style="color: #000000;">) {
        UserBean obj </span>=<span style="color: #000000;"> list.get(i);
        System.out.println(obj.toString());
    }
}

</span><span style="color: #008000;">/**</span><span style="color: #008000;">
 * 通用单个实体查询
 * </span><span style="color: #808080;">@param</span><span style="color: #008000;"> T
 * </span><span style="color: #808080;">@return</span>
 <span style="color: #008000;">*/</span>
<span style="color: #0000ff;">public</span> &lt;T&gt;<span style="color: #000000;"> Specification base_Specification(Class T){
    </span><span style="color: #0000ff;">return</span> <span style="color: #0000ff;">new</span> Specification&lt;T&gt;<span style="color: #000000;">(){
        </span><span style="color: #0000ff;">public</span> Predicate toPredicate(Root&lt;T&gt; root, CriteriaQuery&lt;?&gt;<span style="color: #000000;"> query, CriteriaBuilder cb) {
            Predicate predicate</span>=<span style="color: #000000;">cb.conjunction();
            List</span>&lt;Expression&lt;Boolean&gt;&gt; expression=<span style="color: #000000;">predicate.getExpressions();
            expression.add(cb.like(root.</span>&lt;String&gt; get(""), ""<span style="color: #000000;">));
            </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> predicate;
        }};
}

}

参考链接

Spring Data JPA 简单查询--接口方法 https://www.cnblogs.com/rulian/p/6557471.html

Spring data jpa中Query和@Query分别返回map结果集 https://www.cnblogs.com/wucongyun/p/6730582.html
纯干货，Spring-data-jpa详解，全方位介绍。 http://www.cnblogs.com/dreamroute/p/5173896.html
转载 spring-data-jpa 介绍 复杂查询，包括多表关联，分页，排序等 http://blog.csdn.net/mendeliangyang/article/details/52366799
 

原文地址：https://www.cnblogs.com/litblank/p/8267333.html