JpaSpecificationExecutor接口
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封装 JPA Criteria 查询条件。通常使用匿名内部类的方式来创建该接口的对象
public interface TaskPlanRepository extends JpaRepository<TaskPlan, String>, JpaSpecificationExecutor<TaskPlan> {
}官方接口API：
public interface SpecificationExecutorRepository extends CrudRepository<User, Integer>,
JpaSpecificationExecutor<User> {
}@Service
public class SpecificationExecutorRepositoryManager {
@Autowired
private SpecificationExecutorRepository dao;
/**
* 描述：根据name来查询用户
*/
public User findUserByName(final String name){
return dao.findOne(new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root, CriteriaQuery<?> query,
CriteriaBuilder cb) {
Predicate predicate = cb.equal(root.get("name"), name);
return predicate;
}
});
}
/**
* 描述：根据name和email来查询用户
*/
public User findUserByNameAndEmail(final String name, final String email){
return dao.findOne(new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery<?> query, CriteriaBuilder cb) {
List<Predicate> list = new ArrayList<Predicate>();
Predicate predicate1 = cb.equal(root.get("name"), name);
Predicate predicate2 = cb.equal(root.get("email"), email);
list.add(predicate1);
list.add(predicate2);
// 注意此处的处理
Predicate[] p = new Predicate[list.size()];
return cb.and(list.toArray(p));
}
});
}
/**
* 描述：组合查询
*/
public User findUserByUser(final User userVo){
return dao.findOne(new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery<?> query, CriteriaBuilder cb) {
Predicate predicate = cb.equal(root.get("name"), userVo.getName());
cb.and(predicate, cb.equal(root.get("email"), userVo.getEmail()));
cb.and(predicate, cb.equal(root.get("password"), userVo.getPassword()));
return predicate;
}
});
}
/**
* 描述：范围查询in方法，例如查询用户id在[2,10]中的用户
*/
public List<User> findUserByIds(final List<Integer> ids){
return dao.findAll(new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery<?> query, CriteriaBuilder cb) {
return root.in(ids);
}
});
}
/**
* 描述：范围查询gt方法，例如查询用户id大于9的所有用户
*/
public List<User> findUserByGtId(final int id){
return dao.findAll(new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery<?> query, CriteriaBuilder cb) {
return cb.gt(root.get("id").as(Integer.class), id);
}
});
}
/**
* 描述：范围查询lt方法，例如查询用户id小于10的用户
*/
public List<User> findUserByLtId(final int id){
return dao.findAll(new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery<?> query, CriteriaBuilder cb) {
return cb.lt(root.get("id").as(Integer.class), id);
}
});
}
/**
* 描述：范围查询between方法，例如查询id在3和10之间的用户
*/
public List<User> findUserBetweenId(final int start, final int end){
return dao.findAll(new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery<?> query, CriteriaBuilder cb) {
return cb.between(root.get("id").as(Integer.class), start, end);
}
});
}
/**
* 描述：排序和分页操作
*/
public Page<User> findUserAndOrder(final int id){
Sort sort = new Sort(Direction.DESC, "id");
return dao.findAll(new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery<?> query, CriteriaBuilder cb) {
return cb.gt(root.get("id").as(Integer.class), id);
}
}, new PageRequest(0, 5, sort));
}
/**
* 描述：只有排序操作
*/
public List<User> findUserAndOrderSecondMethod(final int id){
return dao.findAll(new Specification<User>() {
@Override
public Predicate toPredicate(Root<User> root,
CriteriaQuery<?> query, CriteriaBuilder cb) {
cb.gt(root.get("id").as(Integer.class), id);
query.orderBy(cb.desc(root.get("id").as(Integer.class)));
return query.getRestriction();
}
});
}
}@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = { "classpath:applicationContext-config.xml" })
@TransactionConfiguration(defaultRollback = false)
@Transactional
public class SpecificationExecutorRepositoryManagerTest {
@Autowired
private SpecificationExecutorRepositoryManager manager;
@Test
public void testFindUserByName(){
User user = manager.findUserByName("chhliu");
System.out.println(JSON.toJSONString(user));
}
@Test
public void testFindUserByNameAndEmail(){
User user = manager.findUserByNameAndEmail("chhliu", "chhliu@.com");
System.out.println(JSON.toJSONString(user));
}
@Test
public void testFindUserByUserVo(){
User user = new User();
user.setName("chhliu");
user.setEmail("chhliu@.com");
User u = manager.findUserByUser(user);
System.out.println(JSON.toJSONString(u));
}
@Test
public void testFindUserByIds(){
List<User> users = manager.findUserByIds(new ArrayList<Integer>(Arrays.asList(1,3,5,6)));
System.out.println(JSON.toJSONString(users));
}
@Test
public void testFindUserByGtId(){
List<User> users = manager.findUserByGtId(5);
System.out.println(JSON.toJSONString(users));
}
@Test
public void testFindUserByLtId(){
List<User> users = manager.findUserByLtId(5);
System.out.println(JSON.toJSONString(users));
}
@Test
public void testFindUserBetweenId(){
List<User> users = manager.findUserBetweenId(4, 9);
System.out.println(JSON.toJSONString(users));
}
@Test
public void testFindUserAndOrder(){
Page<User> users = manager.findUserAndOrder(1);
System.out.println(JSON.toJSONString(users));
}
@Test
public void testFindUserAndOrderSecondMethod(){
List<User> users = manager.findUserAndOrderSecondMethod(1);
System.out.println(JSON.toJSONString(users));
}
}分页查询
/***
* 项目分页查询
*/
public Page<TaskPlan> getTPListPage(TpFormVO vo) {
Sort sort = new Sort(Sort.Direction.DESC, "createTime").and(new Sort(Sort.Direction.DESC, "code"));
Pageable pageable = new PageRequest(vo.getCurrentPage(), vo.getSize(), sort);
return taskPlanRepository.findAll(new Specification<TaskPlan>() {
@Override
public Predicate toPredicate(Root<TaskPlan> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
List<Predicate> predicates = new ArrayList<Predicate>();
if (StringUtils.isNotBlank(vo.getCreateTimeStart())) {//创建开始时间
predicates.add(cb.greaterThanOrEqualTo(root.<Date> get("createTime"), DateUtils.parseDate(vo.getCreateTimeStart())));
}
if (StringUtils.isNotBlank(vo.getCreateTimeEnd())) {//创建结束时间
predicates.add(cb.lessThanOrEqualTo(root.<Date> get("createTime"), DateUtils.parseDate(vo.getCreateTimeEnd())));
}
if (StringUtils.isNotBlank(vo.getDeliveryTimeStart())) {//交付开始时间
predicates.add(cb.greaterThanOrEqualTo(root.<Date> get("jjqzDate"), DateUtils.parseDate(vo.getDeliveryTimeStart())));
}
if (StringUtils.isNotBlank(vo.getDeliveryTimeEnd())) {//交付结束时间
predicates.add(cb.lessThanOrEqualTo(root.<Date> get("jjqzDate"), DateUtils.parseDate(vo.getDeliveryTimeEnd())));
}
if (StringUtils.isNotBlank(vo.getStatus()) && !vo.isALLStatus()) {//状态
predicates.add(cb.equal(root.<String> get("status"), vo.getStatus()));
}
//默认数据状态为1
predicates.add(cb.equal(root.<String> get("state"), TaskPlan.STATE_TP.state_s.key));
if (!predicates.isEmpty()) {
return cb.and(predicates.toArray(new Predicate[predicates.size()]));
} else {
return cb.conjunction();
}
}
}, pageable);
}实现sql条件">=" 和 "<="的用法
predicates.add(cb.greaterThanOrEqualTo(root.<Date> get("createTime"), DateUtils.parseDate(vo.getCreateTimeStart())));
predicates.add(cb.lessThanOrEqualTo(root.<Date> get("createTime"), DateUtils.parseDate(vo.getCreateTimeEnd())));greaterThanOrEqualTo代表 >= 当前条件时间， lessThanOrEqualTo代表<=当前条件时间，具体代码实现，参考上面的项目分页代码
实现sql条件“=”的用法
Predicate predicate = cb.equal(root.<String> get("state"), TaskPlan.STATE_TP.state_s.key)equal的用法，详细参考上面的项目分页代码
同样的不要忘记notEqual方法
predicates.add(cb.notEqual(root.<String> get("status"), ProcurementInformationEnum.INIT.value));实现sql条件“in”的用法
/**
* 作品分页查询
* @param vo
* @return
*/
public Page<WorkManage> getWorkManageListPage(WorkFormVO vo) {
try{
TaskPlan taskPlan = taskPlanService.getTP(vo.getCode());
Sort sort = new Sort(Sort.Direction.DESC, "taskPlanCascade");
Pageable pageable = new PageRequest(vo.getCurrentPage(), vo.getSize(), sort);
return workManageRepository.findAll(new Specification<WorkManage>() {
@Override
public Predicate toPredicate(Root<WorkManage> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
List<Predicate> predicates = new ArrayList<Predicate>();
if (StringUtils.isNotBlank(vo.getType())) {//类别
if(vo.getType().contains(",")){
CriteriaBuilder.In<Integer> in = cb.in(root.get("type"));
Arrays.stream(vo.getType().split(",")).forEach(type->{
in.value(Integer.parseInt(type));
});
predicates.add(in);
}else{
predicates.add(cb.equal(root.<Integer> get("type"), Integer.parseInt(vo.getType())));
}
}
if (StringUtils.isNotBlank(vo.getMaterial())) {//材质
if(vo.getMaterial().contains(",")){
CriteriaBuilder.In<Integer> in = cb.in(root.get("material"));
Arrays.stream(vo.getMaterial().split(",")).forEach(material->{
in.value(Integer.parseInt(material));
});
predicates.add(cb.or(in));
}else{
predicates.add(cb.equal(root.<Integer> get("material"), Integer.parseInt(vo.getMaterial())));
}
}
if (StringUtils.isNotBlank(vo.getStatus())) {//鉴定状态
Join<Object, Object> workManage2Join = root.join("workManage2");
predicates.add(cb.equal(workManage2Join.<Integer> get("status"), Integer.parseInt(vo.getStatus())));
}
predicates.add(cb.equal(root.<TaskPlan> get("taskPlanCascade"), taskPlan));//关联项目关联
if (!predicates.isEmpty()) {
return cb.and(predicates.toArray(new Predicate[predicates.size()]));
} else {
return cb.conjunction();
}
}
}, pageable);
}catch (Exception e){
logger.error(e.getMessage());
throw_process_exception(RetCode.business_work_exception.code, "业务异常[WORK分页获取异常]", e);
return null;
}
}也是一整块分页代码，其中，in的使用方式，是我们关注的要点如下：
CriteriaBuilder.In<Integer> in = cb.in(root.get("material"));
Arrays.stream(vo.getMaterial().split(",")).forEach(material->{
in.value(Integer.parseInt(material));
});
predicates.add(cb.or(in));通过循环获取值，放到in的属性值里，在最后通过cb.or(in) 连接使用，打印的部分SQL如下：
where (
workmanage0_.TYPE in (
1 , 2
)
)关联查询的用法
Join<Object, Object> workManage2Join = root.join("workManage2");
predicates.add(cb.equal(workManage2Join.<Integer> get("status"), Integer.parseInt(vo.getStatus())));root.join("workManage2") 连接的是当前对象的关联属性对象，创建一个Join对象，就可以通过该join对象，通过查询条件，关联查询数据，具体使用，参考上面的作品分页查询代码
关联实体类查询，就是关联Id查询
predicates.add(cb.equal(root.<WorkManage2> get("workManage2"), workManage2));//这种是关联属性Id查询实现sql条件“or”的用法、"like"的用法
/**
* 分页查询招标管理信息(用于后台)
* @param pageable
* @return
*/
public Page<InviteBidManage> listForPage(final InviteBidManage inviteBidManage, Pageable pageable) {
return inviteBidManageDao.findAll(new Specification<InviteBidManage>() {
@Override
public Predicate toPredicate(Root<InviteBidManage> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
List<Predicate> predicates = new ArrayList<Predicate>();
if (inviteBidManage == null) {
return cb.conjunction();
}
if (StringUtils.isNotBlank(inviteBidManage.getCondition())) {
Predicate projectNamePredicate = cb.like(root.<String> get("projectName"), "%" + inviteBidManage.getCondition() + "%");
Predicate projectCodePredicate = cb.like(root.<String> get("projectCode"), "%" + inviteBidManage.getCondition() + "%");
predicates.add(cb.or(projectNamePredicate, projectCodePredicate));
}
if (StringUtils.isNotBlank(inviteBidManage.getProperty())) {
predicates.add(cb.equal(root.<String> get("property"), inviteBidManage.getProperty()));
}
if (StringUtils.isNotBlank(inviteBidManage.getSource())) {
predicates.add(cb.equal(root.<String> get("source"), inviteBidManage.getSource()));
}
if (inviteBidManage.getState() != null && inviteBidManage.getState() != -1) {
predicates.add(cb.equal(root.<Integer> get("state"), inviteBidManage.getState()));
}
query.orderBy(cb.desc(root.<String> get("createdAt")));
if (!predicates.isEmpty()) {
return cb.and(predicates.toArray(new Predicate[predicates.size()]));
} else {
return cb.conjunction();
}
}
}, pageable);
}根据上面的招标分页查询，or、like的用法如下：
if (StringUtils.isNotBlank(inviteBidManage.getCondition())) {
Predicate projectNamePredicate = cb.like(root.<String> get("projectName"), "%" + inviteBidManage.getCondition() + "%");
Predicate projectCodePredicate = cb.like(root.<String> get("projectCode"), "%" + inviteBidManage.getCondition() + "%");
predicates.add(cb.or(projectNamePredicate, projectCodePredicate));
}具体实现参考招标分页查询实现
排序用法
query.orderBy(cb.desc(root.<String> get("createdAt")));上面的是通过CriteriaBuilder实现排序，也可以通过Pageable的方式实现
Sort sort = new Sort(Sort.Direction.DESC, "createTime").and(new Sort(Sort.Direction.DESC, "code"));
Pageable pageable = new PageRequest(vo.getCurrentPage(), vo.getSize(), sort);具体实现参考招标分页查询实现、项目分页查询实现