springboot jpa 多条件查询（多表）

前几天写的，贴上来。

实体类。

 package com.syl.demo.daomain;

 import lombok.Data;

 import javax.persistence.*;

 /**
  * Created by 孙义朗 on 2017/10/31.
  */
 @Entity
 @Data
 public class User {
     @Id
     private String userId;
     private String userName;
     private String password;
     private String gender;//性别
     private String age;
     @ManyToOne
     private School school;
     @ManyToOne
     private Grade grade;
 }

User

 package com.syl.demo.daomain;

 import lombok.Data;

 import javax.jws.soap.SOAPBinding;
 import javax.persistence.Entity;
 import javax.persistence.Id;
 import javax.persistence.ManyToOne;
 import javax.persistence.OneToMany;

 /**
  * Created by 孙义朗 on 2017/10/31.
  */
 @Data
 @Entity
 public class School {
     @Id
     private String schoolId;
     private String schoolName;

 }

School

 package com.syl.demo.daomain;

 import lombok.Data;

 import javax.persistence.*;

 /**
  * Created by 孙义朗 on 2017/11/16.
  */
 @Entity
 @Data
 public class Grade {
     @Id
     private String gradeId;
     private String gradeName;
     @ManyToOne
     private School school;

 }

Grade

还有一个封装查询条件的类

 package com.syl.demo.daomain;

 import lombok.Data;

 import javax.persistence.Id;

 /**
  * Created by 孙义朗 on 2017/11/16 0016.
  */
 @Data
 public class Params {
     private String userId;
     private String userName;
     private String gender;
     private String age;

     private String gradeName;

     private String schoolName;

 }

Params

Dao层

 package com.syl.demo.dao;

 import com.syl.demo.daomain.Grade;
 import com.syl.demo.daomain.School;
 import com.syl.demo.daomain.User;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.domain.Specification;
 import org.springframework.data.jpa.repository.JpaRepository;

 import java.util.List;

 /**
  * Created by 孙义朗 on 2017/11/16 0016.
  */
 public interface UserRepository extends JpaRepository<User,String> {
     List<User> findAll();

     List<User> findAll(Specification<User> spc, Pageable pageable);

 }

UserRepository

Service及实现

 package com.syl.demo.service;

 import com.syl.demo.daomain.Grade;
 import com.syl.demo.daomain.Params;
 import com.syl.demo.daomain.School;
 import com.syl.demo.daomain.User;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.domain.Specification;

 import java.util.List;

 /**
  * Created by 孙义朗 on 2017/11/16 0016.
  */
 public interface UserService {
     List<User> findAll();

     List<User> findAll(int pageNum, int pageSize,User user);

     List<User> findAll(int pageNum, int pageSize, Params params);

 }

UserService

 package com.syl.demo.service.impl;

 import com.syl.demo.dao.UserRepository;
 import com.syl.demo.daomain.Grade;
 import com.syl.demo.daomain.Params;
 import com.syl.demo.daomain.School;
 import com.syl.demo.daomain.User;
 import com.syl.demo.service.UserService;
 import org.apache.commons.lang3.StringUtils;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.PageRequest;
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.domain.Specification;
 import org.springframework.stereotype.Service;

 import javax.persistence.criteria.*;
 import java.util.ArrayList;
 import java.util.List;

 /**
  * Created by 孙义朗 on 2017/11/16 0016.
  */
 @Service
 public class UserServiceImpl implements UserService {
     @Autowired
     private UserRepository userRepository;

     @Override
     public List<User> findAll() {
         return userRepository.findAll();
     }

     //查询User，单表，多条件
     @Override
     public List<User> findAll(int pageNum, int pageSize, User user) {
         Pageable pageable = new PageRequest(pageNum, pageSize);
         List<User> uList = userRepository.findAll(new Specification<User>() {
             @Override
             public Predicate toPredicate(Root<User> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder cb) {
                 List<Predicate> predicates = new ArrayList<>();
                 if (user.getUserId() != null && !user.getUserId().equals("")) {
                     predicates.add(cb.like(root.get("userId").as(String.class), "%" + user.getUserId() + "%"));
                 }
                 if (user.getUserName() != null && !user.getUserName().equals("")) {
                     predicates.add(cb.like(root.get("userName").as(String.class), "%" + user.getUserName() + "%"));
                 }
                 if (user.getGender() != null && !user.getGender().equals("")) {
                     predicates.add(cb.like(root.get("gender").as(String.class), "%" + user.getGender() + "%"));
                 }
                 if (user.getAge() != null && !user.getAge().equals("")) {
                     predicates.add(cb.like(root.get("age").as(String.class), "%" + user.getAge() + "%"));
                 }
                 Predicate[] pre = new Predicate[predicates.size()];
                 criteriaQuery.where(predicates.toArray(pre));
                 return cb.and(predicates.toArray(pre));
             }
         }, pageable);

         return uList;
     }

     //查询User，多表，多条件
     @Override
     public List<User> findAll(int pageNum, int pageSize, Params params) {
         Pageable pageable = new PageRequest(pageNum, pageSize);
         List<User> uList = userRepository.findAll(new Specification<User>() {
             @Override
             public Predicate toPredicate(Root<User> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder cb) {
                 List<Predicate> list = new ArrayList<>();
                 //根据userId 查询user
                 if (StringUtils.isNotBlank(params.getUserId())) {
                     list.add(cb.equal(root.get("userId").as(String.class), params.getUserId()));
                 }
                 //根据userName 模糊查询user
                 if (StringUtils.isNotBlank(params.getUserName())) {
                     list.add(cb.like(root.get("userName").as(String.class), "%" + params.getUserName() + "%"));
                 }
                 //根据gender 查询user
                 if (StringUtils.isNotBlank(params.getGender())) {
                     list.add(cb.equal(root.get("gender").as(String.class), params.getGender()));
                 }
                 //根据age>? 查询user
                 if (StringUtils.isNotBlank(params.getAge())) {
                     list.add(cb.gt(root.get("age").as(Integer.class), Integer.valueOf(params.getAge())));
                 }
                 //根据gradeName 查询user
                 if (StringUtils.isNotBlank(params.getGradeName())) {
                     Join<Grade, User> join = root.join("grade", JoinType.LEFT);
                     list.add(cb.equal(join.get("gradeName"), params.getGradeName()));
                 }
                 //根据schoolName 查询user
                 if (StringUtils.isNotBlank(params.getSchoolName())) {
                     Join<School, User> join = root.join("grade", JoinType.LEFT);
                     list.add(cb.equal(join.get("school").get("schoolName"), params.getSchoolName()));
                 }
                 Predicate[] pre = new Predicate[list.size()];
                 criteriaQuery.where(list.toArray(pre));
                 return cb.and(list.toArray(pre));
             }
         }, pageable);

         return uList;
     }

 }

UserServiceImpl

控制层

 package com.syl.demo.controller;

 import com.syl.demo.daomain.Grade;
 import com.syl.demo.daomain.Params;
 import com.syl.demo.daomain.School;
 import com.syl.demo.daomain.User;
 import com.syl.demo.service.UserService;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.bind.annotation.*;

 import java.util.List;

 /**
  * Created by 孙义朗 on 2017/11/16 0016.
  */
 @RestController
 public class UserController {
     @Autowired
     UserService userService;

     @GetMapping(value = "/getUser")
     public List<User> getUser() {
         List<User> uList = userService.findAll();
         return uList;
     }

     //查询User，单表，多条件
     @PostMapping(value = "/getUser/{pageNum}/{pageSize}")
     public List<User> getUser(@PathVariable("pageNum") Integer pageNum,
                                @PathVariable("pageSize") Integer pageSize,
                                @RequestBody User user) {
         List<User> uList = userService.findAll(pageNum, pageSize, user);
         return uList;
     }

     //查询User，多表，多条件
     @PostMapping(value = "/getUser2/{pageNum}/{pageSize}")
     public List<User> getUser2(@PathVariable("pageNum") Integer pageNum,
                                @PathVariable("pageSize") Integer pageSize,
                                @RequestBody Params params) {
         List<User> uList = userService.findAll(pageNum, pageSize, params);
         return uList;
     }

 }

UserController

完成。

postman测试效果如下

（单表查询http://www.cnblogs.com/arrrrrya/p/7831248.html）