三天不学习，赶不上比安奇 之 Hibernate Search 的 reindex

以前做过 Hibernate Search的重建索引，就是老老实实的把所有的Mapped Class 找出来，

然后一个Class一个Class的找每个对象进行reindex，代码很长，写的很累。如下，先找到

所有的Class，

 

public void reindex() {
		Session session = getSession();
		
		FullTextSession fullTextSession = Search.getFullTextSession( session);
                fullTextSession.setFlushMode(FlushMode.MANUAL);
		fullTextSession.setCacheMode(CacheMode.IGNORE);
		Transaction tx = fullTextSession.beginTransaction();

		WebApplicationContext cxt = 
			WebApplicationContextUtils.getWebApplicationContext( getServletContext());
		AnnotationSessionFactoryBean factory = (AnnotationSessionFactoryBean) cxt.getBean( "&sessionFactory");
		Iterator iter = factory.getConfiguration().getClassMappings();
		while( iter.hasNext()) {
			RootClass clz = (RootClass) iter.next();
			buildClassIndex( fullTextSession, clz.getMappedClass());
		}

		tx.commit(); //index are written at commit time    
}

 

然后再每个类的对象都找出来build一下：

	private void buildClassIndex(FullTextSession fullTextSession, Class mappedClass) {
		//Scrollable results will avoid loading too many objects in memory
		fullTextSession.purgeAll( mappedClass);

		ScrollableResults results = fullTextSession.createCriteria( mappedClass)
		    .setFetchSize(BATCH_SIZE).scroll( ScrollMode.FORWARD_ONLY );
		int index = 0;
		while( results.next() ) {
		    index++;
		    fullTextSession.index( results.get(0) ); //index each element
		    if (index % BATCH_SIZE == 0) {
		        fullTextSession.flush(); //apply changes to indexes
		        fullTextSession.clear(); //clear since the queue is processed
		    }
		}
	}

 

很复杂吧。现在简单多了，两行代码：

public void reindex() {
		FullTextSession fullTextSession = Search.getFullTextSession( getSession());
		fullTextSession.createIndexer().startAndWait();

}

 

还可以用异步的方式来进行重建索引，直接调用 fullTextSession.createIndexer().start(); 就可以了。

真是三天不学习，赶不上比安奇。