Spring Data JPA实现动态条件与范围查询实例代码

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;  }}

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);  }}

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;  }}

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;@NoRepositoryBeanpublic 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);  }}

@Entity@Data@AllArgsConstructor@NoArgsConstructorpublic class Person {  @Id  @GeneratedValue  private Long id;  private String name;  private Integer height;  @DateTimeFormat(pattern = "yyyy-MM-dd")  private Date birthday;}

public interface PersonRepository extends WiselyRepository<Person,Long> {}

@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);  }}