hibernate空格导致的错误!

数据库中已经有两条记录,这是为了测试数据用的。

  下面是我对hibernate中查询进行的测试....

package cn.lwk.dao;

import java.util.List;

import org.hibernate.classic.Session;

import cn.itcast.utils.HibernateUtils;

public class EntityDao extends HibernateUtils{
	public <T> List<T> find(Class<T> t){
		Session session = sessionFactory.openSession();
		 List userList = session.createQuery("from"+t.getName()).list();
		 session.close();
		 return userList;
		
	}
}

下面是测试数据

package cn.lwk.test;

import static org.junit.Assert.*;

import java.util.List;

import org.junit.Test;

import cn.lwk.dao.EntityDao;
import cn.lwk.domain.User;

public class EntityDaoTest {

	@Test
	public void testFind() {
		EntityDao entityDao=new EntityDao();
		List<User> users = entityDao.find(User.class);
		System.out.println(users.size());
	}

}
但是运行结果却出乎意料....
java.lang.IllegalArgumentException: node to traverse cannot be null!
<span style="white-space:pre">	</span>at org.hibernate.hql.ast.util.NodeTraverser.traverseDepthFirst(NodeTraverser.java:63)
<span style="white-space:pre">	</span>at org.hibernate.hql.ast.QueryTranslatorImpl.parse(QueryTranslatorImpl.java:280)
<span style="white-space:pre">	</span>at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:182)
<span style="white-space:pre">	</span>at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
<span style="white-space:pre">	</span>at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:101)
<span style="white-space:pre">	</span>at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
<span style="white-space:pre">	</span>at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:98)
<span style="white-space:pre">	</span>at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:156)
<span style="white-space:pre">	</span>at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:135)
<span style="white-space:pre">	</span>at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1760)
<span style="white-space:pre">	</span>at cn.lwk.dao.EntityDao.find(EntityDao.java:12)
<span style="white-space:pre">	</span>at cn.lwk.test.EntityDaoTest.testFind(EntityDaoTest.java:17)
<span style="white-space:pre">	</span>at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
<span style="white-space:pre">	</span>at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
<span style="white-space:pre">	</span>at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
<span style="white-space:pre">	</span>at java.lang.reflect.Method.invoke(Method.java:606)
<span style="white-space:pre">	</span>at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
<span style="white-space:pre">	</span>at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
<span style="white-space:pre">	</span>at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
<span style="white-space:pre">	</span>at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
<span style="white-space:pre">	</span>at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
<span style="white-space:pre">	</span>at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
<span style="white-space:pre">	</span>at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
<span style="white-space:pre">	</span>at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
<span style="white-space:pre">	</span>at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
<span style="white-space:pre">	</span>at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
<span style="white-space:pre">	</span>at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
<span style="white-space:pre">	</span>at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
<span style="white-space:pre">	</span>at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
<span style="white-space:pre">	</span>at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
<span style="white-space:pre">	</span>at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
<span style="white-space:pre">	</span>at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
<span style="white-space:pre">	</span>at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
<span style="white-space:pre">	</span>at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
<span style="white-space:pre">	</span>at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)


原因:

List userList = session.createQuery("from"+" "+t.getName()).list();
from后面加上空格....发现运行出了结果

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