JPA集成queryDSL，灵活查询 (3.实现条件查询，排序，分页功能)

1.在实际开发中，遇到一个接口。需要分页，排序，条件查询。使用JPA实现会比较麻烦。使用queryDSL便能够很轻松实现。

不废话，直接上代码。

Controller层：

import com.five.fiveeducation.entity.Student;
import com.five.fiveeducation.service.EducationService;
import com.querydsl.core.types.Predicate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.data.querydsl.binding.QuerydslPredicate;
import org.springframework.data.web.PageableDefault;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;

@PostMapping(value = "findHost")
public List<Student> findHost(@PageableDefault(sort = {"host"},direction = Sort.Direction.DESC) Pageable pageable){
    return educationService.findHost(pageable).getContent();
}

先实现按照host属性排序，分页的功能

Service层：

import com.five.fiveeducation.dao.EducationDao;
import com.five.fiveeducation.entity.QStudent;
import com.five.fiveeducation.entity.Student;
import com.querydsl.core.types.Predicate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;

public Page<Student> findHost(Pageable pageable) {
    QStudent student = QStudent.student;
    Predicate  predicate = student.startDate.after(new Date());
    return educationDao.findAll(predicate,pageable);
}

完成复杂查询功能，本人也是刚接触，后续有更复杂的查询也会分享。同时希望大家多多交流。