Spring Data Jpa分页多条件关联查询

1、新建资讯实体类
import com.yzyxtech.project.tianfutalents.common.entity.IdentityEntity;
import com.yzyxtech.project.tianfutalents.core.entity.company.Company;
import com.yzyxtech.project.tianfutalents.core.entity.company.EnterpriseMember;
import com.yzyxtech.project.tianfutalents.core.entity.enums.NewsStatus;
import io.swagger.annotations.ApiModelProperty;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;

import javax.persistence.Entity;
import javax.persistence.EnumType;
import javax.persistence.Enumerated;
import javax.persistence.ManyToOne;

/**
 * Created by zhao on 2018/11/2.
 * 资讯
 */
@Getter//自动生成getter和setter--》lombok
@Setter
@ToString
@Entity
public class News extends IdentityEntity{

    @ManyToOne
    private NewsColumn newsColumn;//资讯栏目 类似板块、如农业资讯、招聘资讯、政策法规等

    @ManyToOne
    private NewsClassify newsClassify;//资讯分类

    @ApiModelProperty("标题")
    private String title;

    @ApiModelProperty("简介")
    private String synopsis;

    @ApiModelProperty("封面图")
    private String headImg;

    @ApiModelProperty("内容")
    private String content;

    @ApiModelProperty("公司")
    @ManyToOne
    private Company company;

    @ApiModelProperty("发布人")
    @ManyToOne
    private EnterpriseMember enterpriseMember;

    @ApiModelProperty("状态")
    @Enumerated(EnumType.STRING)
    private NewsStatus status;

}

枚举类状态

public interface EnumGetNameInterface {
    String getName();
}
import com.yzyxtech.project.tianfutalents.common.serializer.jackson.EnumGetNameInterface;
import lombok.AllArgsConstructor;
import lombok.Getter;

/**
 * Created by gyw on 2018/11/9.
 */
@Getter
@AllArgsConstructor//自动生成全字段构造函数
public enum NewsStatus implements EnumGetNameInterface {
    APPROVED("审核通过"),
    PENDING("待审"),
    REJECTED("不通过");

    private String name;
}

2、新建资讯表单搜索

import com.yzyxtech.project.tianfutalents.common.utils.DateUtils;
import com.yzyxtech.project.tianfutalents.core.entity.company.Company;
import com.yzyxtech.project.tianfutalents.core.entity.company.CompanyProduct;
import com.yzyxtech.project.tianfutalents.core.entity.company.EnterpriseMember;
import com.yzyxtech.project.tianfutalents.core.entity.enums.NewsStatus;
import com.yzyxtech.project.tianfutalents.core.entity.headhunter.Customer;
import com.yzyxtech.project.tianfutalents.core.entity.headhunter.CustomerContact;
import com.yzyxtech.project.tianfutalents.core.entity.headhunter.Project;
import com.yzyxtech.project.tianfutalents.core.entity.news.News;
import com.yzyxtech.project.tianfutalents.core.entity.news.NewsClassify;
import com.yzyxtech.project.tianfutalents.core.entity.news.NewsColumn;
import com.yzyxtech.project.tianfutalents.core.entity.setting.City;
import com.yzyxtech.project.tianfutalents.core.entity.setting.WorkFunction;
import io.swagger.annotations.ApiModelProperty;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;
import org.apache.commons.lang3.StringUtils;
import org.springframework.data.jpa.domain.Specification;

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

/**
 * @Description:    企业资讯条件查询
 * @Author:         gyw
 * @CreateDate:     2018/11/23 11:18
 */
@Getter
@Setter
@ToString
public class NewsSearch implements Specification {
    @ApiModelProperty("资讯ID")
    private Long id;

    @ApiModelProperty("资讯栏目")
    private String  newsColumnName;

    @ApiModelProperty("资讯分类")
    private String newsClassifyName;

    @ApiModelProperty("标题")
    private String title;

    @ApiModelProperty("公司")
    private String companyName;

    @ApiModelProperty("发布人")
    private String enterpriseMemberName;

    @ApiModelProperty("状态[APPROVED,PENDING,REJECTED]")
    private String status;

    @Override
    public Predicate toPredicate(Root root, CriteriaQuery criteriaQuery, CriteriaBuilder cb) {
        List list = new ArrayList<>();

        if (this.id != null) {
            list.add(cb.equal(root.get("id"), this.id));
        }
        if (StringUtils.isNotBlank(this.newsColumnName)) {
            Join newsNewsColumnJoin = root.join("newsColumn");//关联表
            list.add(cb.like(newsNewsColumnJoin.get("name"),"%" + this.newsColumnName + "%"));
        }
        if (StringUtils.isNotBlank(this.newsClassifyName)) {
            Join newsNewsClassifyJoin = root.join("newsClassify");//关联表
            list.add(cb.like(newsNewsClassifyJoin.get("name"),"%" + this.newsClassifyName + "%"));
        }
        if (StringUtils.isNotBlank(this.title)) {
            list.add(cb.like(root.get("title"), "%" + this.title + "%"));
        }
        if (StringUtils.isNotBlank(this.companyName)) {
            Join companyJoin = root.join("company");关联表
            list.add(cb.like(companyJoin.get("name"),"%" + this.companyName + "%"));
        }
        if (StringUtils.isNotBlank(this.enterpriseMemberName)) {
            Join enterpriseMember = root.join("enterpriseMember");
            list.add(cb.like(enterpriseMember.get("name"),"%" + this.enterpriseMemberName + "%"));
        }

        if (this.status != null) {
            list.add(cb.equal(root.get("status"), NewsStatus.valueOf(this.status)));
        }

        /*if (StringUtils.isNotBlank(this.status != null) {
                Predicate p1 = cb.like(root.get(Recruitment_.name), "%" + search.getQ() + "%");
                Predicate p2 = cb.like(root.get(Recruitment_.tags), "%" + search.getQ() + "%");
                Predicate p3 = cb.like(root.get(Recruitment_.description), "%" + search.getQ() + "%");

                list.add(cb.or(p1, p2, p3));
         }
        if (this.startTime != null) {//大于等于
            list.add(cb.greaterThanOrEqualTo(root.get(News_.startTime), DateUtils.localDate2OffsetDateTime(this.startTime)));
        }

        if (this.endTime != null) {//小于等于
                    list.add(cb.lessThanOrEqualTo(root.get(News_.startTime),         DateUtils.localDate2OffsetDateTime(this.endTime)));
        }*/
        return cb.and(list.toArray(new Predicate[0]));
    }
}

3、新建返回数据

import com.yzyxtech.project.tianfutalents.core.entity.company.Company;
import com.yzyxtech.project.tianfutalents.core.entity.company.EnterpriseMember;
import com.yzyxtech.project.tianfutalents.core.entity.enums.NewsStatus;
import com.yzyxtech.project.tianfutalents.core.entity.news.News;
import com.yzyxtech.project.tianfutalents.core.entity.news.NewsClassify;
import com.yzyxtech.project.tianfutalents.core.entity.news.NewsColumn;
import io.swagger.annotations.ApiModelProperty;
import lombok.Getter;
import lombok.Setter;
import lombok.ToString;
import org.springframework.beans.BeanUtils;

/**
* @Description:    资讯返回数据
* @Author:         gyw
* @CreateDate:     2018/11/24 13:38
*/
@Getter
@Setter
@ToString
public class NewsJson {
    @ApiModelProperty("资讯ID")
    private Long id;

    @ApiModelProperty("资讯栏目")
    private NewsColumn newsColumn;

    @ApiModelProperty("资讯分类")
    private NewsClassify newsClassify;

    @ApiModelProperty("标题")
    private String title;

    @ApiModelProperty("简介")
    private String synopsis;

    @ApiModelProperty("封面图")
    private String headImg;

    @ApiModelProperty("内容")
    private String content;

    @ApiModelProperty("公司")
    private Company company;

    @ApiModelProperty("发布人")
    private Long enterpriseMemberId;

    @ApiModelProperty("发布姓名")
    private String enterpriseMemberName;

    @ApiModelProperty("状态[APPROVED,PENDING,REJECTED]")
    private NewsStatus status;//枚举

    public static NewsJson convert(News entity) {
        NewsJson json = new NewsJson();
        BeanUtils.copyProperties(entity, json);
        EnterpriseMember enterpriseMember = entity.getEnterpriseMember();
        if(enterpriseMember==null){
            enterpriseMember = new EnterpriseMember();
        }
        json.setEnterpriseMemberId(enterpriseMember.getId());
        json.setEnterpriseMemberName(enterpriseMember.getName());
        return json;
    }
}

3、查询简单封装

import org.springframework.data.jpa.domain.Specification;

import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
import java.util.ArrayList;
import java.util.List;
/**
* @Description:    部分查询封装
* @Author:         gyw
* @CreateDate:     2018/11/30 9:28
*/
public class SelectUtil {
    /**
     * 选择是否要查询删除的
     * @param deleted true-查询删除的   false-未删除  null-所以
     * @param 
     */
    public static Specification getIsDeleted(Boolean deleted){
        Specification specification = (root, query, cb)->{
            List predicates = new ArrayList<>();
            predicates.add(SelectUtil.getPredicate(deleted,root, query, cb));
            return cb.and(predicates.toArray(new Predicate[0]));
        };
        return specification;
    }

    /**
     * 添加删除条件查询
     * @param deleted true-查询删除的   false-未删除  null-所以
     * @param root
     * @param criteriaQuery
     * @param cb
     * @param 
     * @return
     */
    public static Predicate getPredicate(Boolean deleted, Root root, CriteriaQuery criteriaQuery, CriteriaBuilder cb){
        List predicates = new ArrayList<>();
        if(deleted==null){
            return cb.and(predicates.toArray(new Predicate[0]));
        }else if(deleted){
            predicates.add(cb.isFalse(root.get("enabled")));
            predicates.add(cb.isTrue(root.get("deleted")));
        }else{
            predicates.add(cb.isTrue(root.get("enabled")));
            predicates.add(cb.isFalse(root.get("deleted")));
        }
        return cb.and(predicates.toArray(new Predicate[0]));
    }

    public static void main(String[] args){

    }
}

4、新建ServiceImpl类

import com.yzyxtech.project.tianfutalents.common.domain.PageResult;
import com.yzyxtech.project.tianfutalents.core.entity.news.News;
import com.yzyxtech.project.tianfutalents.core.repository.news.NewsRepository;
import com.yzyxtech.project.tianfutalents.core.resource.json.news.NewsJson;
import com.yzyxtech.project.tianfutalents.core.resource.news.form.NewsSearch;
import com.yzyxtech.project.tianfutalents.core.service.news.NewsService;
import com.yzyxtech.project.tianfutalents.core.utils.SelectUtil;
import org.springframework.beans.BeanUtils;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import javax.persistence.criteria.Predicate;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

@Service
public class NewsServiceImpl implements NewsService {

    @Resource
    private NewsRepository newsRepository;

    @Override
    @Transactional//事物--如果有延迟加载可以用这个在session后关闭前在返回json中对延迟数据直接拿到
    public PageResult listPageByCondition(NewsSearch newsSearch, Integer page, Integer pageSize) {
       Page newsPage = newsRepository.findAll(((root, query, cb) -> {
            List list = new ArrayList<>();
            list.add(newsSearch.toPredicate(root, query, cb));
            list.add(SelectUtil.getPredicate(false,root, query, cb));
            return cb.and(list.toArray(new Predicate[0]));
        }), PageRequest.of(page - 1, pageSize));

        return new PageResult<>//返回数据类型样式
                (
                    newsPage.getTotalElements(),
                    newsPage.getTotalPages(),
                    pageSize,
                    newsPage.getContent().stream()
                    .map(NewsJson::convert)
                    .collect(Collectors.toList())
                );
    }

}

5、dao类接口

import com.yzyxtech.project.tianfutalents.core.entity.news.News;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
import org.springframework.data.jpa.repository.Query;

import java.util.List;
//JpaRepository--部分查询--@NoRepositoryBean（自带这个注解继承就自动注入）
//JpaSpecificationExecutor--分页条件查询
public interface NewsRepository extends JpaRepository, JpaSpecificationExecutor {

    @Query(value = "from News where newsClassify.id=?1 and deleted=0 and enabled = 1")
    List findByNewsClassifyId(Long newsClassifyId);
}

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