spring data jpa 条件分页查询
PS:一半转载，一半自己的用例
作者：javaniu
链接：https://www.zhihu.com/question/37873032/answer/73991650来源：知乎
著作权归作者所有，转载请联系作者获得授权。（ PS:暂时没有知乎账号，所以没有联系原作者，请原作者见谅！）
springdata jpa总结的查询方法有如下：
- findOneByName按用户名查询User对象
- findAllByLargeThanId查询id号大于指定参数值的User对象列表，分页Page返回
- findAllByIdAndName查询id和用户名等于指定参数值的User对象，可以通过多个Predicate来查询
- findAllByLikeName模糊分页查询用户名，like查询
- findAllByInIds查询指定的id集合用户对象列表
- findAllByIds通过原生sql查询指定的用户id对象列表
- findAllByName通过JPA query查询用户名等于指定值的用户对象
- 多个排序语法: Sort sort = new Sort(Direction.DESC, "sort").and(new Sort(Direction.DESC, "id"));
package com.zuidaima.springdata.service.impl;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.Resource;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Path;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
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.stereotype.Service;
import com.zuidaima.springdata.entity.User;
import com.zuidaima.springdata.repository.UserRepository;
import com.zuidaima.springdata.service.UserService;
/**
* *@author javaniu 2013-06-04 22:27:23
*/
@Service
public class UserServiceImpl implements UserService {
@Resource
public UserRepository userRepository;
@Override
public User findOneByName(final String name) {
Specification<User> specification = new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery query, CriteriaBuilder criteriaBuilder) {
Predicate _name = criteriaBuilder.equal(root.get("name"), name);
return criteriaBuilder.and(_name);
}
};
return userRepository.findOne(specification);
}
@Override
public Page<User> findAllByLargeThanId(final Long id, int page, int count,
Sort sort) {
Specification<User> specification = new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery query, CriteriaBuilder criteriaBuilder) {
Path<Long> $id = root.get("id");
Predicate _id = criteriaBuilder.gt($id, id);
return criteriaBuilder.and(_id);
}
};
Pageable pageable = new PageRequest(page - 1, count, sort);
return userRepository.findAll(specification, pageable);
}
@Override
public User findAllByIdAndName(final Long id, final String name) {
Specification<User> specification = new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery query, CriteriaBuilder criteriaBuilder) {
List<Predicate> predicates = new ArrayList<Predicate>();
Path<Long> $id = root.get("id");
Predicate _id = criteriaBuilder.equal($id, id);
predicates.add(_id);
Path<Long> $name = root.get("name");
Predicate _name = criteriaBuilder.equal($name, name);
predicates.add(_name);
return criteriaBuilder.and(predicates
.toArray(new Predicate[] {}));
}
};
return userRepository.findOne(specification);
}
@Override
public Page<User> findAllByLikeName(final String name, int page, int count) {
Specification<User> specification = new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery query, CriteriaBuilder criteriaBuilder) {
Path<String> _name = root.get("name");
Predicate _key = criteriaBuilder.like(_name, "%" + name + "%");
return criteriaBuilder.and(_key);
}
};
Sort sort = new Sort(Direction.DESC, "id");
Pageable pageable = new PageRequest(page - 1, count, sort);
return userRepository.findAll(specification, pageable);
}
@Override
public Page<User> findAllByInIds(final List<Long> ids) {
Specification<User> specification = new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery query, CriteriaBuilder criteriaBuilder) {
return criteriaBuilder.in(root.get("id")).value(ids);
}
};
int page = 1;
int count = ids.size();
Sort sort = new Sort(Direction.DESC, "id");
Pageable pageable = new PageRequest(page - 1, count, sort);
return userRepository.findAll(specification, pageable);
}
@Override
public List<User> findAllByIds(List<Long> ids) {
return userRepository.findAllByIds(ids);
}
@Override
public User findAllByName(String name) {
return userRepository.findAllByName(name);
}
}===================================== 华丽分割线 ===============================================
以下是我在项目中的实际运用：
1.实体类：GsTest(这里就不贴代码了)
2.Dao层：
@Repository
public interface GsTestDao extends JpaRepository,JpaSpecificationExecutor{
}
3.Service层 :（也可以是单独的某个参数，详情见上面），page:页数，conut:每页的条数，sort:排序
Page findOneByName(GsTest gsTest,int page,int count,Sort sort);
4.ServiceImpl层
//分頁 条件为年龄和 姓名。
@Override
public Page findOneByName(final GsTest gsTest,int page,int count,Sort sort) {
Specification specification = new Specification() {
@Override
public Predicate toPredicate(Root root,
CriteriaQuery query, CriteriaBuilder criteriaBuilder) {
List predicates = new ArrayList();
//参数非空判断。不为空则加此条件
if (!gsTest.getAge().isEmpty()) {
Predicate _age = criteriaBuilder.equal(root.get("age"), gsTest.getAge());
predicates.add(_age);
System.out.println("_age:"+gsTest.getAge().isEmpty());
}
Predicate _name = criteriaBuilder.equal(root.get("name"), gsTest.getName());
predicates.add(_name);
/ /return criteriaBuilder.and(_name);
return criteriaBuilder.and(predicates.toArray(new Predicate[]{}));
}
};
4.controller:控制层
/**
*
* @param gsTestDto 实体，用来接收传来JSON类型参数
* @param pageNumber 页数
* @param pageSize 条数
* @return
*/
@RequestMapping(value="/fin",method = RequestMethod.POST)
@ResponseBody
public Page findTest(@RequestBody GsTestDto gsTestDto,@RequestParam(value = "page", defaultValue = "1") int pageNumber,
@RequestParam(value = "size", defaultValue = Constants.PAGE_SIZE_10) int pageSize){
GsTest gsTest = new GsTest();
gsTest=converterIn.convertIn(gsTestDto);
System.out.println("GsTestDto:"+gsTest);
//排序
Sort sort = new Sort(Direction.ASC, "id");
Page findOneByName = gsTestDaoService.findOneByName(gsTest,pageNumber,pageSize,sort);
return findOneByName;
}
到此，条件分页就完成了。看看测试结果：
我用的是 谷歌的Postman来进行测试：
1.传参：
{
"name": "jak"
}
结果：
{
"content": [
{
"id": 3,
"properties_string": null,
"name": "jak",
"age": "21",
"sex": "女",
"status": "1",
"certime": "2013-05-11 09:00:00"
},
{
"id": 4,
"properties_string": null,
"name": "jak",
"age": "21",
"sex": "女",
"status": "1",
"certime": "2013-05-11 09:00:00"
},
{
"id": 5,
"properties_string": null,
"name": "jak",
"age": "21",
"sex": "女",
"status": "1",
"certime": "2013-05-11 09:00:00"
}
],
"size": 10,
"number": 0,
"sort": [
{
"direction": "ASC",
"property": "id",
"ascending": true
}
],
"lastPage": true,
"firstPage": true,
"totalPages": 1,
"totalElements": 3,
"numberOfElements": 3
}
2.传错误的参数：
{
"name": "jak",
"age":"22"
}
结果：
{
"content": [],
"size": 10,
"number": 0,
"sort": [
{
"direction": "ASC",
"property": "id",
"ascending": true
}
],
"lastPage": true,
"firstPage": true,
"totalPages": 0,
"totalElements": 0,
"numberOfElements": 0
}
可以看得到 查不到的时候。content 是空值！
到此，简单的条件分页查询就完成了，我也是小白，不妥之处见谅！
===============2017年3月2日10:28:46======= 华丽分割线 ===============================================
注：接着上面的
实体类：prid
实体类中有一个时间属性：
private Date beginTime; private Date endTime;
JPA 查询运用的时候应该是：
SimpleDateFormat sdf2 = new SimpleDateFormat("yyyy-MM-dd");
Predicate dueTime = criteriaBuilder.between(root.get("dueTime"),sdf2.parse(prid.getBeginTime()),sdf2.parse(prid.getEndTime()));
注：parse()返回的是一个Date类型数据