我有一個'複雜'的問題。
休眠異常處理
我正在使用Hibernate/JPA與數據庫進行交易。
我不是DBA,客戶端使用我的應用程序,一個RESTful Web服務。我的問題是數據庫被改變(不是很頻繁,但仍然會改變)。此外,客戶並不總是尊重我的應用程序(長度,類型等)的輸入。發生這種情況時,Hibernate會拋出異常。這個異常很難翻譯和從日誌中讀取,因爲它嵌套了異常,並且包含很多文本:就像我說的,很難理解。
我想知道是否有可能在實體級別上處理異常,拋出一個定製的異常。
我感謝您的耐心和提前幫助。
編輯:
Fianlly我能夠做到我想要的東西,如果沒有確定它做了正確的方式。
App.java
package com.mc;
import org.hibernate.Session;
import com.mc.stock.Stock;
import com.mc.util.HibernateUtil;
import javax.persistence.EntityManager;
public class App {
public static void main(String[] args) {
Set<ConstraintViolation<Stock>> violations;
validator = Validation.buildDefaultValidatorFactory().getValidator();
Scanner scan = new Scanner(System.in);
EntityManager em = null;
System.out.println("Hibernate one to many (Annotation)");
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction();
Stock stock = new Stock();
String nextLine = scan.nextLine();
stock.setStockCode(nextLine.toString());
nextLine = scan.nextLine();
stock.setStockName(nextLine.toString());
violations = validator.validate(stock);
if (violations.size() > 0) {
StringBuilder excepcion = new StringBuilder();
for (ConstraintViolation<Stock> violation : violations) {
excepcion.append(violation.getMessageTemplate());
excepcion.append("\n");
}
System.out.println(excepcion.toString());
}
session.save(stock);
session.getTransaction().commit();
}
}
FieldMatch.java
package com.mc.constraints;
import com.mc.constraints.impl.FieldMatchValidator;
import javax.validation.Constraint;
import javax.validation.Payload;
import java.lang.annotation.Documented;
import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.TYPE;
import java.lang.annotation.Retention;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Target;
@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = FieldMatchValidator.class)
@Documented
public @interface FieldMatch {
String message() default "{constraints.fieldmatch}";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
String first();
String second();
@Target({TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Documented
@interface List {
FieldMatch[] value();
}
}
FieldMatchValidator.java
package com.mc.constraints.impl;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import com.mc.constraints.FieldMatch;
import org.apache.commons.beanutils.BeanUtils;
public class FieldMatchValidator implements ConstraintValidator<FieldMatch, Object> {
private String firstFieldName;
private String secondFieldName;
@Override
public void initialize(final FieldMatch constraintAnnotation) {
firstFieldName = constraintAnnotation.first();
secondFieldName = constraintAnnotation.second();
}
@Override
public boolean isValid(final Object value, final ConstraintValidatorContext context) {
try {
final Object firstObj = BeanUtils.getProperty(value, firstFieldName);
final Object secondObj = BeanUtils.getProperty(value, secondFieldName);
return firstObj == null && secondObj == null || firstObj != null && firstObj.equals(secondObj);
} catch (final Exception ignore) {
// ignore
}
return true;
}
}
Stock.java
package com.mc.stock;
import com.mc.constraints.FieldMatch;
import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.Basic;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.SequenceGenerator;
import javax.persistence.Table;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlTransient;
import org.hibernate.annotations.Cascade;
import org.hibernate.annotations.CascadeType;
import org.hibernate.validator.constraints.Length;
@Entity
@Table(name = "STOCK")
@XmlRootElement
@NamedQueries({
@NamedQuery(name = "Stock.findAll", query = "SELECT s FROM Stock s"),
@NamedQuery(name = "Stock.findByStockId", query = "SELECT s FROM Stock s WHERE s.stockId = :stockId"),
@NamedQuery(name = "Stock.findByStockCode", query = "SELECT s FROM Stock s WHERE s.stockCode = :stockCode"),
@NamedQuery(name = "Stock.findByStockName", query = "SELECT s FROM Stock s WHERE s.stockName = :stockName")})
@FieldMatch.List({
@FieldMatch(first = "stockCode", second = "stockName", message = "Code and Stock must have same value")
})
public class Stock implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "seq_stock_id")
@SequenceGenerator(name = "seq_stock_id", sequenceName = "seq_stock_id", initialValue = 1, allocationSize = 1)
@Basic(optional = false)
@Column(name = "STOCK_ID", unique = true, nullable = false)
private Integer stockId;
@Column(name = "STOCK_CODE")
private String stockCode;
@Length(min = 1, max = 20, message = "{wrong stock name length}")
@Column(name = "STOCK_NAME")
private String stockName;
public Stock() {
}
public Stock(Integer stockId) {
this.stockId = stockId;
}
public Integer getStockId() {
return stockId;
}
public void setStockId(Integer stockId) {
this.stockId = stockId;
}
public String getStockCode() {
return stockCode;
}
public void setStockCode(String stockCode) {
this.stockCode = stockCode;
}
public String getStockName() {
return stockName;
}
public void setStockName(String stockName) {
this.stockName = stockName;
}
@Override
public int hashCode() {
int hash = 0;
hash += (stockId != null ? stockId.hashCode() : 0);
return hash;
}
@Override
public boolean equals(Object object) {
// TODO: Warning - this method won't work in the case the id fields are not set
if (!(object instanceof Stock)) {
return false;
}
Stock other = (Stock) object;
if ((this.stockId == null && other.stockId != null) || (this.stockId != null && !this.stockId.equals(other.stockId))) {
return false;
}
return true;
}
@Override
public String toString() {
return "com.mc.stock.Stock[ stockId=" + stockId + " ]";
}
}
HibernateUtil.java
package com.mc.util;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static final SessionFactory sessionFactory = buildSessionFactory();
private static SessionFactory buildSessionFactory() {
try {
// Create the SessionFactory from hibernate.cfg.xml
return new Configuration().configure().buildSessionFactory();
} catch (Throwable ex) {
// Make sure you log the exception, as it might be swallowed
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
public static void shutdown() {
// Close caches and connection pools
getSessionFactory().close();
}
}
Oracle數據庫結構
CREATE TABLE stock
(
STOCK_ID NUMBER(5) NOT NULL ,
STOCK_CODE VARCHAR2(10) NULL ,
STOCK_NAME VARCHAR2(20) NULL
);
ALTER TABLE stock
add CONSTRAINT PK_STOCK_ID PRIMARY KEY (STOCK_ID);
create sequence seq_stock_id
start with 1
increment by 1
nomaxvalue;
同意這一點。在大多數情況下,處理基於Hibernate/DB異常的業務異常爲時已晚。 –
我試過這個,看起來不錯,但我仍然得到像http://pastebin.com/RT2JdQca這樣的很長的例外。我只是想拋出「interpolatedMessage」 –