Hibernate4 拦截器(Interceptor) 实现实体类增删改的日志记录

转自：https://blog.youkuaiyun.com/he90227/article/details/44783099

开发应用程序的过程中，经常会对一些比较重要的数据修改都需要写日志。在实际工作的工程中，这些数据都是存在表中的, 一个常见的做法是用触发器，在增删改的时候，用触发器将数据写入到另一张表中去，但个人不推荐这么做，原因如下:
1. 如果有多个表，得写很多触发器。
2. 触发器与数据库特性关联太紧，不同的数据库，虽然思路一样，但语法却不太一样。
对数据库表操作的日志记录，完全可以利用Hibernate的Interceptor特性来实现，也就是拦截器。下面用一个具体的例子来说明如何使用Hibernate的Interceptor。

创建一个表，用来记录日志的表 

Create TABLE  `auditlog` (
  `AUDIT_LOG_ID` BIGINT(20) UNSIGNED NOT NULL AUTO_INCREMENT,
  `ACTION` VARCHAR(100) NOT NULL,
  `DETAIL` text NOT NULL,
  `CreateD_DATE` DATE NOT NULL,
  `ENTITY_ID` BIGINT(20) UNSIGNED NOT NULL,
  `ENTITY_NAME` VARCHAR(255) NOT NULL,
  PRIMARY KEY (`AUDIT_LOG_ID`)
) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8;

创建这个表对应的实体类:

@Entity
@Table(name = "auditlog")
public class AuditLog implements java.io.Serializable {
    private Long auditLogId;
    private String action;
    private String detail;
    private Date createdDate;
    private long entityId;
    private String entityName;
    public AuditLog() {
    }
    public AuditLog(String action, String detail, Date createdDate,
            long entityId, String entityName) {
        this.action = action;
        this.detail = detail;
        this.createdDate = createdDate;
        this.entityId = entityId;
        this.entityName = entityName;
    }
    @Id
    @GeneratedValue(strategy = IDENTITY)
    @Column(name = "AUDIT_LOG_ID", unique = true, nullable = false)
    public Long getAuditLogId() {
        return this.auditLogId;
    }
        .... 余下部分可以参考提供下载的源代码.

创建一个接口，所有实现了这个接口的实体类，都会写日志

package com.mkyong.interceptor;
//market interface
public interface IAuditLog {    
    public Long getId();    
    public String getLogDeatil();
}

这里有两个方法,getId,getLogDetail 需要实现类去实现具体的方法，也就是要被写入到日志表中的详细记录.

创建一个类实现了IAuditLog 接口，并给出接口方法的具体实现

@Entity
@Table(name="stock")
public class Stock implements java.io.Serializable,IAuditLog  {
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(name="STOCK_ID")
    private Integer stockId;
    
    @Column(name="STOCK_CODE", length=10)
    private String stockCode;
    
    @Column(name="STOCK_NAME", length=20)
    private String stockName;
    public Stock() {
    }
    public Stock(String stockCode, String stockName) {
        this.stockCode = stockCode;
        this.stockName = stockName;
    }
    ....省略部分getter,setter。
    @Transient
    public Long getId(){
        return this.stockId.longValue();
    }
    
    @Transient
    public String getLogDeatil(){
        StringBuilder sb = new StringBuilder();
        sb.append(" Stock Id : ").append(stockId)
        .append(" Stock Code : ").append(stockCode)
        .append(" Stock Name : ").append(stockName);
        return sb.toString();
    }
}

创建记录日志的工具类，所有写日志公用 

public class AuditLogUtil{
    
    public static void LogIt(String action,
        IAuditLog entity){
        
        Session tempSession = HibernateUtil.getSessionFactory().openSession();
            
        try {
            tempSession.getTransaction().begin();
            AuditLog auditRecord = new AuditLog(action,entity.getLogDeatil()
                    , new Date(),entity.getId(), entity.getClass().toString());
            tempSession.save(auditRecord);
            tempSession.getTransaction().commit();
            
        } finally {    
            tempSession.close();
            
        }
            
    }
}

创建 Hibernate interceptor 拦截器，这是重点，这里拦截所有需要记录日志的类,并处理 

public class AuditLogInterceptor extends EmptyInterceptor{
    
    Session session;
    private Set inserts = new HashSet();
    private Set updates = new HashSet();
    private Set deletes = new HashSet();
    
    public void setSession(Session session) {
        this.session=session;
    }
        
    @Override
    public String onPrepareStatement(String sql) {
        System.out.println("execute sql: " + sql);
        return super.onPrepareStatement(sql);
    }
    public boolean onSave(Object entity,Serializable id,
        Object[] state,String[] propertyNames,Type[] types)
        throws CallbackException {
        
        System.out.println("onSave");
        
        if (entity instanceof IAuditLog){
            inserts.add(entity);
        }
        return false;
            
    }
    
    public boolean onFlushDirty(Object entity,Serializable id,
        Object[] currentState,Object[] previousState,
        String[] propertyNames,Type[] types)
        throws CallbackException {
    
        System.out.println("onFlushDirty");
        
        if (entity instanceof IAuditLog){
            updates.add(entity);
        }
        return false;
        
    }
    
    public void onDelete(Object entity, Serializable id, 
        

转载于:https://www.cnblogs.com/sharpest/p/10020849.html