Spingboot JPA CriteriaBuilder 如何获取指定字段
作者：sunlight
这篇文章 主要介绍了Spingboot JPA CriteriaBuilder 如何获取指定字段，具有很好的参考价值，希望对大家有所帮助。如有错误或未考虑完全的地方，望不吝赐教
Spingboot JPA CriteriaBuilder获取指定字段
废话不说直接贴代码
public class ActivityVO implements Serializable {
private static final long serialVersionUID = 1L;
private int id;
private String name;
private String thumb;
public ActivityVO(int id, String name, String thumb) {
this.id = id;
this.name = name;
this.thumb = thumb;
}
public ActivityVO(){
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getThumb() {
return thumb;
}
public void setThumb(String thumb) {
this.thumb = thumb;
}
}
import org.hibernate.annotations.NotFound;
import org.hibernate.annotations.NotFoundAction;
import java.io.Serializable;
import javax.persistence.*;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.List;
import java.util.Map;
import java.util.Objects;
/**
* The persistent class for the activity database table.
*
*/
@Entity
@Table(name="activity")
//@JsonIgnoreProperties({"user"})
//@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
//@NamedQuery(name = "Task.findByTaskName", query = "select t from Task t where t.taskName = ?1")
public class ActivityEntity implements Serializable {
private static final long serialVersionUID = 1L;
public ActivityEntity(int id, String name, String thumb) {
this.id = id;
this.name = name;
}
private int id;
private Integer userId;
private String name;
private String thumb;
private byte type;
private byte mode;
private String notes;
private String content;
private BigDecimal deposit;
private byte status;
private int productNum;
private Integer participantNum;
private Integer wxId;
private Integer mpId;
private String mpRelpyKeyword;
private BigInteger startTime;
private byte lotteryType;
private BigInteger lotteryTime;
private int maxParticipantNum;
private byte enableBlacklist;
private byte enableSharing;
private byte isVisible;
private BigInteger createTime;
private BigInteger updateTime;
public ActivityEntity() {
}
@Id
@Column(name = "id")
@GeneratedValue(strategy=GenerationType.IDENTITY)
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
@Basic
@Column(name = "user_id")
public Integer getUserId() {
return userId;
}
public void setUserId(Integer userId) {
this.userId = userId;
}
@Basic
@Column(name = "name")
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Basic
@Column(name = "thumb")
public String getThumb() {
return thumb;
}
public void setThumb(String thumb) {
this.thumb = thumb;
}
@Basic
@Column(name = "type")
public byte getType() {
return type;
}
public void setType(byte type) {
this.type = type;
}
@Basic
@Column(name = "mode")
public byte getMode() {
return mode;
}
public void setMode(byte mode) {
this.mode = mode;
}
@Basic
@Column(name = "notes")
public String getNotes() {
return notes;
}
public void setNotes(String notes) {
this.notes = notes;
}
@Basic
@Column(name = "content")
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
@Basic
@Column(name = "deposit")
public BigDecimal getDeposit() {
return deposit;
}
public void setDeposit(BigDecimal deposit) {
this.deposit = deposit;
}
@Basic
@Column(name = "status")
public byte getStatus() {
return status;
}
public void setStatus(byte status) {
this.status = status;
}
@Basic
@Column(name = "product_num")
public int getProductNum() {
return productNum;
}
public void setProductNum(int productNum) {
this.productNum = productNum;
}
@Basic
@Column(name = "participant_num")
public Integer getParticipantNum() {
return participantNum;
}
public void setParticipantNum(Integer participantNum) {
this.participantNum = participantNum;
}
@Basic
@Column(name = "wx_id")
public Integer getWxId() {
return wxId;
}
public void setWxId(Integer wxId) {
this.wxId = wxId;
}
@Basic
@Column(name = "mp_id")
public Integer getMpId() {
return mpId;
}
public void setMpId(Integer mpId) {
this.mpId = mpId;
}
@Basic
@Column(name = "mp_relpy_keyword")
public String getMpRelpyKeyword() {
return mpRelpyKeyword;
}
public void setMpRelpyKeyword(String mpRelpyKeyword) {
this.mpRelpyKeyword = mpRelpyKeyword;
}
@Basic
@Column(name = "start_time")
public BigInteger getStartTime() {
return startTime;
}
public void setStartTime(BigInteger startTime) {
this.startTime = startTime;
}
@Basic
@Column(name = "lottery_type")
public byte getLotteryType() {
return lotteryType;
}
public void setLotteryType(byte lotteryType) {
this.lotteryType = lotteryType;
}
@Basic
@Column(name = "lottery_time")
public BigInteger getLotteryTime() {
return lotteryTime;
}
public void setLotteryTime(BigInteger lotteryTime) {
this.lotteryTime = lotteryTime;
}
@Basic
@Column(name = "max_participant_num")
public int getMaxParticipantNum() {
return maxParticipantNum;
}
public void setMaxParticipantNum(int maxParticipantNum) {
this.maxParticipantNum = maxParticipantNum;
}
@Basic
@Column(name = "enable_blacklist")
public byte getEnableBlacklist() {
return enableBlacklist;
}
public void setEnableBlacklist(byte enableBlacklist) {
this.enableBlacklist = enableBlacklist;
}
@Basic
@Column(name = "enable_sharing")
public byte getEnableSharing() {
return enableSharing;
}
public void setEnableSharing(byte enableSharing) {
this.enableSharing = enableSharing;
}
@Basic
@Column(name = "is_visible")
public byte getIsVisible() {
return isVisible;
}
public void setIsVisible(byte isVisible) {
this.isVisible = isVisible;
}
@Basic
@Column(name = "create_time")
public BigInteger getCreateTime() {
return createTime;
}
public void setCreateTime(BigInteger createTime) {
this.createTime = createTime;
}
@Basic
@Column(name = "update_time")
public BigInteger getUpdateTime() {
return updateTime;
}
public void setUpdateTime(BigInteger updateTime) {
this.updateTime = updateTime;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
ActivityEntity that = (ActivityEntity) o;
return id == that.id &&
type == that.type &&
mode == that.mode &&
status == that.status &&
productNum == that.productNum &&
lotteryType == that.lotteryType &&
maxParticipantNum == that.maxParticipantNum &&
enableBlacklist == that.enableBlacklist &&
Objects.equals(userId, that.userId) &&
Objects.equals(name, that.name) &&
Objects.equals(thumb, that.thumb) &&
Objects.equals(notes, that.notes) &&
Objects.equals(content, that.content) &&
Objects.equals(deposit, that.deposit) &&
Objects.equals(participantNum, that.participantNum) &&
Objects.equals(wxId, that.wxId) &&
Objects.equals(mpId, that.mpId) &&
Objects.equals(mpRelpyKeyword, that.mpRelpyKeyword) &&
Objects.equals(startTime, that.startTime) &&
Objects.equals(lotteryTime, that.lotteryTime) &&
Objects.equals(createTime, that.createTime) &&
Objects.equals(updateTime, that.updateTime) &&
Objects.equals(user, that.user);
}
@Override
public int hashCode() {
return Objects.hash(id, userId, name, thumb, type, mode, notes, content, deposit, status, productNum, participantNum, wxId, mpId, mpRelpyKeyword, startTime, lotteryType, lotteryTime, maxParticipantNum, enableBlacklist, createTime, updateTime, user);
}
@Override
public String toString() {
return "ActivityEntity{" +
"id=" + id +
", userId=" + userId +
", name='" + name + '\'' +
", thumb='" + thumb + '\'' +
", type=" + type +
", mode=" + mode +
", notes='" + notes + '\'' +
", content='" + content + '\'' +
", deposit=" + deposit +
", status=" + status +
", productNum=" + productNum +
", participantNum=" + participantNum +
", wxId=" + wxId +
", mpId=" + mpId +
", mpRelpyKeyword='" + mpRelpyKeyword + '\'' +
", startTime=" + startTime +
", lotteryType=" + lotteryType +
", lotteryTime=" + lotteryTime +
", maxParticipantNum=" + maxParticipantNum +
", enableBlacklist=" + enableBlacklist +
", createTime=" + createTime +
", updateTime=" + updateTime +
", user=" + user +
'}';
}
}
@PersistenceContext//@Autowired和@PersistenceContext注解任取一
EntityManager entityManager;
public List<ActivityVO> findAllByPage(Pageable pageable) throws Exception {
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder();
CriteriaQuery<Tuple> criteriaQuery = criteriaBuilder.createTupleQuery();
Root<ActivityEntity> root = criteriaQuery.from(ActivityEntity.class);
criteriaQuery.multiselect( root.get("id"), root.get("name"),root.get("thumb") );
Predicate restrictions = criteriaBuilder.conjunction();
restrictions = criteriaBuilder.and(restrictions, criteriaBuilder.equal(root.get("id"), 1));
criteriaQuery.where(restrictions);
criteriaQuery.orderBy(criteriaBuilder.desc(root.get("id")));
TypedQuery<Tuple> query = entityManager.createQuery(criteriaQuery).setFlushMode(FlushModeType.COMMIT);
List<Tuple> tuples = query.getResultList();
ActivityVO adminWrapper = null;
List<ActivityVO> lists = new ArrayList<ActivityVO>();
for (Tuple t : tuples) {
adminWrapper = new ActivityVO();
adminWrapper.setId((Integer) t.get(0));
adminWrapper.setName((String)t.get(1));
adminWrapper.setThumb((String)t.get(2));
lists.add(adminWrapper);
}
return lists;
}
}
Java JPA CriteriaBuilder使用
一个复杂的查询例子
包含常用的所有查询方法
CriteriaBuilder criteriaBuilder = entityManager.getCriteriaBuilder(); //查询结果所需要的类型(Entity相对应)
CriteriaQuery<Entity> criteriaQuery = criteriaBuilder.createQuery(Entity.class); //查询所需要的主体类（Entity0相对应）
Root<Entity0> root = criteriaQuery.from(Entity0.class); //查询结果-select（此处查询所有符合条件的主体类）
criteriaQuery.select(root); //过滤条件用Predicate方法拼接
Predicate restrictions = criteriaBuilder.conjunction(); //过滤条件——equal（当Entity0关联member类时，Entity0：member=m：1）
restrictions = criteriaBuilder.and(restrictions, criteriaBuilder.equal(root.get("member"), member));
//过滤条件——like
restrictions = criteriaBuilder.and(restrictions, criteriaBuilder.like(root.<String>get("str"), "%"+str+"%"));
//用户名查询（member里面的username匹配） ———— 多层查询 ———— 子查询的一种：适用于m:1或1:1（即多对一或一对一）
restrictions = criteriaBuilder.and(restrictions, criteriaBuilder.like(root.get("member").<String>get("username"), "%"+username+"%"));
//子查询（规范写法，先判断查询内容是否存在）（适用于1：m）（即一对多）
if (searchType != null || searchValue != null || hasExpired != null || status != null || type != null || isPendingReceive != null || isPendingRefunds != null || isAllocatedStock != null || businessType != null) {
//建立子查询 Subquery<Order> orderSubquery = criteriaQuery.subquery(Order.class);
Root<Order> orderSubqueryRoot = orderSubquery.from(Order.class);
orderSubquery.select(orderSubqueryRoot); //子查询和父查询相关联
Predicate orderRestrictions = criteriaBuilder.equal(orderSubqueryRoot.<MergeOrder>get("mergeOrder"), root);
//子查询过滤条件拼接
if (searchType != null && searchValue != null) {if ("phone".equals(searchType)) {
orderRestrictions = criteriaBuilder.and(orderRestrictions, criteriaBuilder.like(orderSubqueryRoot.<String>get("phone"), "%"+searchValue+"%"));
}
}if (type != null) {
CriteriaBuilder.In<Order.Type> in = criteriaBuilder.in(orderSubqueryRoot.<Order.Type>get("type"));
in.value(type);
orderRestrictions = criteriaBuilder.and(orderRestrictions, in);
}
//and、or以及判断是否为null，比较（>）的使用（比较可以用于日期比较）
if (hasExpired != null) {
orderRestrictions = criteriaBuilder.and(orderRestrictions, criteriaBuilder.or(orderSubqueryRoot.get("expire").isNull(), criteriaBuilder.greaterThan(orderSubqueryRoot.<Date>get("expire"), new Date())));
}
// not的使用方法（不符合上述过滤条件），notEqual的使用，<（小于）的使用
if (isPendingReceive != null) {
restrictions = criteriaBuilder.and(restrictions, criteriaBuilder.equal(root.get("paymentMethodType"), PaymentMethod.Type.cashOnDelivery));
Predicate predicate = criteriaBuilder.and(criteriaBuilder.or(orderSubqueryRoot.get("expire").isNull()
, criteriaBuilder.greaterThan(orderSubqueryRoot.<Date>get("expire"), new Date()))
, criteriaBuilder.notEqual(orderSubqueryRoot.get("status"), Order.Status.completed)
, criteriaBuilder.lessThan(orderSubqueryRoot.<BigDecimal>get("amountPaid"), orderSubqueryRoot.<BigDecimal>get("amount")));
if (isPendingReceive) {
orderRestrictions = criteriaBuilder.and(orderRestrictions, criteriaBuilder.not(predicate));
}
}// 多层查询使用if (businessType != null) {
orderRestrictions = criteriaBuilder.and(orderRestrictions, criteriaBuilder.equal(orderSubqueryRoot.get("store").get("business").get("businessType"), businessType));
} // 拼接过滤条件
orderSubquery.where(orderRestrictions);
// 和总条件拼接（exists的使用）
restrictions = criteriaBuilder.and(restrictions, criteriaBuilder.exists(orderSubquery));
}
criteriaQuery.where(restrictions); TypedQuery<Entity> query = entityManager.createQuery(criteriaQuery); Entity singleResult = query.getSingleResult();
以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。