springDataJpa入門教程
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springDataJpa入門教程（1）-基於springBoot的基本增刪改查
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springDataJpa入門教程（2）-Specification動態條件查詢+排序+分頁
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springDataJpa入門教程（3-1）-基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁
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springDataJpa入門教程（3-2）-基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁返回自定義實體類對象
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springDataJpa入門教程（4）-Example單表動態條件查詢+分頁
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springDataJpa入門教程（5）-單表動態條件查詢+分頁
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springDataJpa入門教程（6）-多表動態條件查詢+分頁
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springDataJpa入門教程（7）-基於springDataJpa投影(Projection)返回自定義實體類對象
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springDataJpa入門教程（8）-JPA EnableJpaAuditing 審計功能
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springDataJpa入門教程（9）-spring jpa實體屬性類型轉換器AttributeConverter的用法
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springDataJpa入門教程（10）-JPA使用過程中遇到的坑及解決方法
springDataJpa入門教程（3-2）-基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁返回自定義實體類對象
在上一節，講到了基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁，查詢的結果集是用Object數組封裝的，查詢起來不是很方便。所以這節來介紹如何將EntityManager的查詢結果封裝到自定義實體類對象中。有需要源碼的朋友，請到git上下載源碼，源碼地址：源碼下載地址。java學習交流羣：184998348,歡迎大家一起交流學習。
1.需求：根據用戶名、年齡，生日（開始時間-結束時間）、城市名稱查詢用戶分頁列表，查詢結果按照用戶創建時間排序。
實體類分別是User類、Address類，下面這兩個類的代碼：
package com.thizgroup.jpa.study.model;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
@Entity
@Table(name = "tb_user")
@Data//使用lombok生成getter、setter
@NoArgsConstructor//生成無參構造方法
public class User {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column(name = "name",columnDefinition = "varchar(64)")
private String name;
@Column(name = "mobile",columnDefinition = "varchar(64)")
private String mobile;
@Column(name = "email",columnDefinition = "varchar(64)")
private String email;
@Column(name = "age",columnDefinition = "smallint(64)")
private Integer age;
@Column(name = "birthday",columnDefinition = "timestamp")
private Date birthday;
//地址
@Column(name = "address_id",columnDefinition = "bigint(20)")
private Long addressId;
@Column(name = "create_date",columnDefinition = "timestamp")
private Date createDate;
@Column(name = "modify_date",columnDefinition = "timestamp")
private Date modifyDate;
@Builder(toBuilder = true)
public User(Long id,String name, String mobile, String email, Integer age, Date birthday,
Long addressId) {
this.id = id;
this.name = name;
this.mobile = mobile;
this.email = email;
this.age = age;
this.birthday = birthday;
this.addressId = addressId;
}
}
package com.thizgroup.jpa.study.model;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import lombok.Data;
@Entity
@Table(name="tb_address")
@Data//使用lombok生成getter、setter
public class Address {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Column(name = "country",columnDefinition = "varchar(64)")
private String country;
@Column(name = "province",columnDefinition = "varchar(64)")
private String province;
@Column(name = "city",columnDefinition = "varchar(64)")
private String city;
}
- 涉及到DTO及輔助類
package com.thizgroup.jpa.study.dto;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class UserInfo2 {
private Long id;
private String name;//姓名
private int age;//年齡
private Date birthday;//生日
private String mobile;//電話
private String email;//郵箱
private String country;//國家
private String province;//省份
private String city;//城市
private Date createTime;//創建時間
}
package com.thizgroup.jpa.study.dto;
import java.io.Serializable;
import java.util.List;
import lombok.Data;
import lombok.Getter;
import org.springframework.util.Assert;
@Data//使用lombok生成getter、setter
public class PageBean implements Serializable {
@Getter
private long totalCount;//總記錄數
@Getter
private int totalPages;//總頁數
@Getter
private int pageNumber;//第幾頁
@Getter
private int pageSize;//每頁條數
public PageBean(int pageNumber, int pageSize, long totalCount) {
pageNumber = pageNumber <0 ? 0 :pageNumber;//jpa中頁碼從0開始
pageSize = pageSize <=0 ? 15 : pageSize;//默認取15條記錄
//計算總頁數
int totalPages = (int)((totalCount+pageSize-1)/pageSize);
//計算起始頁
if(totalPages>0){
pageNumber = totalPages <= pageNumber ? totalPages-1 : pageNumber;
}
this.pageNumber = pageNumber;
this.pageSize = pageSize;
this.totalPages = totalPages;
this.totalCount = totalCount;
}
public PageBean(PageBean pageBean) {
Assert.notNull(pageBean,"pagebean cannot be null");
this.pageNumber = pageBean.getPageNumber();
this.pageSize = pageBean.getPageSize();
this.totalPages = pageBean.getTotalPages();
this.totalCount = pageBean.getTotalCount();
}
}
package com.thizgroup.jpa.study.dto;
import java.util.List;
import lombok.Data;
import lombok.Getter;
@Data
public class PageRecord<T> extends PageBean {
@Getter
private List<T> data;//數據列表
public PageRecord(int pageNumber, int pageSize, long totalCount,List<T> data) {
super(pageNumber, pageSize, totalCount);
this.data = data;
}
public PageRecord(PageBean pageBean, List<T> data){
super(pageBean);
this.data =data;
}
}
直接上UserDao的代碼，
package com.thizgroup.jpa.study.dao;
import com.thizgroup.jpa.study.dto.AddressDTO;
import com.thizgroup.jpa.study.dto.PageBean;
import com.thizgroup.jpa.study.dto.PageRecord;
import com.thizgroup.jpa.study.dto.UserDTO;
import com.thizgroup.jpa.study.dto.UserInfo;
import com.thizgroup.jpa.study.dto.UserInfo2;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.Query;
import org.apache.commons.lang3.StringUtils;
import org.hibernate.query.internal.NativeQueryImpl;
import org.hibernate.transform.Transformers;
import org.hibernate.type.StandardBasicTypes;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Repository;
/**
* 用戶服務
*/
@Repository
public class UserDao {
@Autowired
private EntityManager entityManager;
//使用entityManager實現多表聯合帶條件帶分頁查詢及排序
public PageRecord<UserInfo2> findUserListByPage3(UserDTO userDTO, Pageable pageable){
List<Object> args = new ArrayList<>();//用於封裝參數
StringBuffer sql = new StringBuffer();
sql.append(
" select u.id as id,u.name as name,u.age as age,u.birthday as birthday,u.mobile as mobile,"
+ "u.email as email,a.country as country,a.province as province,a.city as city "
+ ", u.create_date as createTime"
+ " from tb_user u "
+ " left join tb_address a on u.address_id = a.id "
+ " where 1=1 "
);
if(userDTO != null){
if(StringUtils.isNotBlank(userDTO.getName())){
//模糊查詢
sql.append(" and u.name like ? ");
args.add("%"+userDTO.getName()+"%");
}
if(null != userDTO.getAge()){
//精確查詢
sql.append(" and u.age = ? ");
args.add(userDTO.getAge());
}
//求生日在某個時間段範圍內的用戶
if(null != userDTO.getStartTime()){
//大於等於
sql.append(" and u.birthday >= ? ");
args.add(userDTO.getStartTime());
}
if(null != userDTO.getEndTime()){
//小於等於
sql.append(" and u.birthday <= ? ");
args.add(userDTO.getEndTime());
}
if(userDTO.getAddressDTO() != null) {
AddressDTO addressDTO = userDTO.getAddressDTO();
//查詢某個城市的用戶
if(StringUtils.isNotBlank(addressDTO.getCity())) {
sql.append(" and a.city = ? ");
args.add(addressDTO.getCity());
}
}
}
//按照創建時間倒序排序
sql.append(" order by u.create_date desc ");
//創建query對象
NativeQueryImpl query = entityManager.createNativeQuery(sql.toString())
.unwrap(NativeQueryImpl.class);
query.setResultTransformer(Transformers.aliasToBean(UserInfo2.class));
query.addScalar("id", StandardBasicTypes.LONG);
query.addScalar("name",StandardBasicTypes.STRING);
query.addScalar("age",StandardBasicTypes.INTEGER);
query.addScalar("birthday",StandardBasicTypes.TIMESTAMP);
query.addScalar("mobile",StandardBasicTypes.STRING);
query.addScalar("email",StandardBasicTypes.STRING);
query.addScalar("country",StandardBasicTypes.STRING);
query.addScalar("province",StandardBasicTypes.STRING);
query.addScalar("city",StandardBasicTypes.STRING);
query.addScalar("createTime",StandardBasicTypes.TIMESTAMP);
//設置查詢參數
if(args.size()>0){
for(int i=0;i<args.size();i++){
//注意：jpa的setParameter是從1開始的
query.setParameter(i+1,args.get(i));
}
}
PageBean pageBean = findPageBean(sql.toString(), args, pageable);
//分頁查詢
query.setFirstResult(pageBean.getPageNumber()*pageBean.getPageSize());
query.setMaxResults(pageBean.getPageNumber()*pageBean.getPageSize()+pageBean.getPageSize());
List<UserInfo2> resultList = query.list();
return new PageRecord<UserInfo2>(pageBean,resultList);
}
}
寫個單元測試驗證一下，
package com.thizgroup.jpa.study.dao;
import com.thizgroup.jpa.study.JpaApplication;
import com.thizgroup.jpa.study.dto.PageRecord;
import com.thizgroup.jpa.study.dto.UserInfo;
import com.thizgroup.jpa.study.dto.UserInfo2;
import java.util.ArrayList;
import java.util.List;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.domain.PageRequest;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
@SpringBootTest(classes={JpaApplication.class})
@RunWith(SpringJUnit4ClassRunner.class)
@Transactional(readOnly = false,propagation = Propagation.REQUIRED)
public class UserDaoTest {
@Autowired
private UserDao userDao;
@Test
public void findUserListByPage3Test(){
PageRecord<UserInfo2> pageRecord = userDao
.findUserListByPage3(null, PageRequest.of(0, 15));
System.out.println("分頁信息：");
System.out.println("總記錄數："+pageRecord.getTotalCount()+",總頁數："+pageRecord.getTotalPages());
System.out.println("頁碼："+(pageRecord.getPageNumber()+1)+",每頁條數："+pageRecord.getPageSize());
List<UserInfo2> content = pageRecord.getData();
content = null == content? new ArrayList<>() : content;
content.forEach(user->System.out.println(user));
}
}
執行一下單元測試，
分頁信息：
總記錄數：3,總頁數：1
頁碼：1,每頁條數：15
UserInfo2(id=3, name=諸葛亮, age=54, birthday=2001-09-16 08:00:00.0, mobile=158989989, email=zhu@qq.com, country=中國, province=湖北, city=武漢, createTime=2019-09-06 05:50:01.0)
UserInfo2(id=1, name=張三, age=35, birthday=2008-09-16 08:00:00.0, mobile=156989989, email=hu@qq.com, country=中國, province=上海, city=上海, createTime=2019-08-06 05:50:01.0)
UserInfo2(id=2, name=狄仁傑, age=50, birthday=1988-09-16 08:00:00.0, mobile=158789989, email=di@qq.com, country=中國, province=湖北, city=武漢, createTime=2019-07-06 05:50:01.0)
好了，至此，springDataJpa基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁返回自定義實體類對象就介紹完了，有需要源碼的朋友，請到git上下載源碼，源碼地址：https://github.com/hgq0916/springdatajpa-study.git。java學習交流羣：184998348,歡迎大家一起交流學習。