欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识！
您现在的位置是： 首页  >  IT编程

Spring Data JPA实现动态条件与范围查询实例代码

程序员文章站 2023-12-16 19:28:46
spring data jpa为我们提供了query with example来实现动态条件查询，当查询条件为空的时候，我们不用做大量的条件判断。但是query with...

spring data jpa为我们提供了query with example来实现动态条件查询，当查询条件为空的时候，我们不用做大量的条件判断。但是query with example却不支持范围查询(包括日期范围，数值范围查询)，本文通过specification实现了既支持动态条件查询又支持范围查询的方法。

1 实现方式

1.1 范围对象range定义

import java.io.serializable;


public class range<e> implements serializable {
  private static final long serialversionuid = 1l;

  private string field;
  private comparable from;
  private comparable to;
  private boolean includenull;


  public range(string field) {
    this.field = field;
  }


  public range(string field, comparable from, comparable to) {
    this.field = field;
    this.from = from;
    this.to = to;
  }

  public range(string field, comparable from, comparable to, boolean includenull) {
    this.field = field;
    this.from = from;
    this.to = to;
    this.includenull = includenull;
  }


  public range(range<e> other) {
    this.field = other.getfield();
    this.from = other.getfrom();
    this.to = other.getto();
    this.includenull = other.getincludenull();
  }

  public string getfield() {
    return field;
  }

  public comparable getfrom() {
    return from;
  }


  public void setfrom(comparable from) {
    this.from = from;
  }

  public boolean isfromset() {
    return getfrom() != null;
  }


  public comparable getto() {
    return to;
  }

  public void setto(comparable to) {
    this.to = to;
  }

  public boolean istoset() {
    return getto() != null;
  }

  public void setincludenull(boolean includenull) {
    this.includenull = includenull;
  }

  public boolean getincludenull() {
    return includenull;
  }

  public boolean isincludenullset() {
    return includenull != null;
  }

  public boolean isbetween() {
    return isfromset() && istoset();
  }

  public boolean isset() {
    return isfromset() || istoset() || isincludenullset();
  }

  public boolean isvalid() {
    if (isbetween()) {
      return getfrom().compareto(getto()) <= 0;
    }

    return true;
  }
}

1.2 example的specification

import org.springframework.data.domain.example;
import org.springframework.data.jpa.convert.querybyexamplepredicatebuilder;
import org.springframework.data.jpa.domain.specification;
import org.springframework.util.assert;

import javax.persistence.criteria.criteriabuilder;
import javax.persistence.criteria.criteriaquery;
import javax.persistence.criteria.predicate;
import javax.persistence.criteria.root;

/**
 * created by wangyunfei on 2017/6/6.
 */
public class byexamplespecification<t> implements specification<t> {
  private final example<t> example;

  public byexamplespecification(example<t> example) {

    assert.notnull(example, "example must not be null!");
    this.example = example;
  }


  @override
  public predicate topredicate(root<t> root, criteriaquery<?> query, criteriabuilder cb) {
    return querybyexamplepredicatebuilder.getpredicate(root, cb, example);
  }
}

1.3 range的specification

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.list;

import static com.google.common.collect.iterables.toarray;
import static com.google.common.collect.lists.newarraylist;
import static java.lang.boolean.false;
import static java.lang.boolean.true;

/**
 * created by wangyunfei on 2017/6/6.
 */
public class byrangespecification<t> implements specification<t> {
  private final list<range<t>> ranges;

  public byrangespecification(list<range<t>> ranges) {
    this.ranges = ranges;
  }

  @override
  public predicate topredicate(root<t> root, criteriaquery<?> query, criteriabuilder builder) {
    list<predicate> predicates = newarraylist();

    for (range<t> range : ranges) {
      if (range.isset()) {
        predicate rangepredicate = buildrangepredicate(range, root, builder);

        if (rangepredicate != null) {
          if (!range.isincludenullset() || range.getincludenull() == false) {
            predicates.add(rangepredicate);
          } else {
            predicates.add(builder.or(rangepredicate, builder.isnull(root.get(range.getfield()))));
          }
        }

        if (true == range.getincludenull()) {
          predicates.add(builder.isnull(root.get(range.getfield())));
        } else if (false == range.getincludenull()) {
          predicates.add(builder.isnotnull(root.get(range.getfield())));
        }
      }
    }
    return predicates.isempty() ? builder.conjunction() : builder.and(toarray(predicates, predicate.class));
  }

  private predicate buildrangepredicate(range<t> range, root<t> root, criteriabuilder builder) {
    if (range.isbetween()) {
      return builder.between(root.get(range.getfield()), range.getfrom(), range.getto());
    } else if (range.isfromset()) {
      return builder.greaterthanorequalto(root.get(range.getfield()), range.getfrom());
    } else if (range.istoset()) {
      return builder.lessthanorequalto(root.get(range.getfield()), range.getto());
    }
    return null;
  }

}

1.4 自定义repository与实现

import org.springframework.data.domain.example;
import org.springframework.data.domain.page;
import org.springframework.data.domain.pageable;
import org.springframework.data.jpa.repository.jparepository;
import org.springframework.data.repository.norepositorybean;

import java.io.serializable;
import java.util.list;

@norepositorybean
public interface wiselyrepository<e, pk extends serializable> extends jparepository<e, pk> {


 page<e> querybyexamplewithrange(example example,list<range<e>> ranges, pageable pageable);

}

import org.springframework.data.domain.example;
import org.springframework.data.domain.page;
import org.springframework.data.domain.pageable;
import org.springframework.data.jpa.domain.specification;
import org.springframework.data.jpa.repository.support.jpaentityinformation;
import org.springframework.data.jpa.repository.support.simplejparepository;

import javax.persistence.entitymanager;
import java.io.serializable;
import java.util.list;

import static org.springframework.data.jpa.domain.specifications.where;


public class wiselyrepositoryimpl<e, pk extends serializable> extends simplejparepository<e, pk> implements
    wiselyrepository<e, pk> {
  private final entitymanager entitymanager;

  public wiselyrepositoryimpl(jpaentityinformation entityinformation, entitymanager entitymanager) {
    super(entityinformation, entitymanager);
    this.entitymanager = entitymanager;
  }



  @override
  public page<e> querybyexamplewithrange(example example, list<range<e>> ranges, pageable pageable) {
    specification<e> byexample = new byexamplespecification<>(example);
    specification<e> byranges = new byrangespecification<>(ranges);
    return findall(where(byexample).and(byranges),pageable);
  }
}

2 使用方式

2.1 开启支持

通过@enablejparepositories(repositorybaseclass = wiselyrepositoryimpl.class)开启对定义功能的支持。

2.2 示例

实体类

@entity
@data
@allargsconstructor
@noargsconstructor
public class person {
  @id
  @generatedvalue
  private long id;
  private string name;
  private integer height;
  @datetimeformat(pattern = "yyyy-mm-dd")
  private date birthday;
}

personrepository

public interface personrepository extends wiselyrepository<person,long> {
}

测试控制器

@restcontroller
@requestmapping("/people")
public class personcontroller {

  @autowired
  personrepository personrepository;

  @postmapping
  public responseentity<person> save(@requestbody person person){
    person p = personrepository.save(person);
    return new responseentity<person>(p, httpstatus.created);
  }


  @getmapping
  public responseentity<page<person>> query(person person,
                       @datetimeformat(pattern = "yyyy-mm-dd")date startdate,
                       @datetimeformat(pattern = "yyyy-mm-dd")date enddate,
                       integer startheight,
                       integer endheight,
                       pageable pageable){
    example<person> personexample = example.of(person);

    list<range<person>> ranges = newarraylist();
    range<person> birthrange = new range<person>("birthday",startdate,enddate);
    range<person> heightrange = new range<person>("height",startheight,endheight);
    ranges.add(birthrange);
    ranges.add(heightrange);

    page<person> page = personrepository.querybyexamplewithrange(personexample,ranges,pageable);

    return new responseentity<page<person>>(page,httpstatus.ok);

  }
}

源码地址：

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。

上一篇：

下一篇：

推荐阅读