org.hibernate.hql.ast.QuerySyntaxError: User is not mapped. [from User where username=?]
at org.hibernate.hql.ast.ErrorCounter.throwQueryException(ErrorCounter.java:63)
at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:196)
at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:130)
at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:83)
at org.hibernate.impl.SessionFactoryImpl.getQuery(SessionFactoryImpl.java:427)
at org.hibernate.impl.SessionImpl.getQueries(SessionImpl.java:884)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:834)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:74)
at org.hibernate.impl.AbstractQueryImpl.uniqueResult(AbstractQueryImpl.java:603)
at com.demo.hibernate.dao.UserDAOImpl.select(UserDAOImpl.java:19)
at com.demo.hibernate.service.UserServiceImpl.login(UserServiceImpl.java:21)
at com.demo.hibernate.test.UserServiceTest.testLogin(UserServiceTest.java:25)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at junit.framework.TestCase.runTest(TestCase.java:154)
at junit.framework.TestCase.runBare(TestCase.java:127)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:118)
at junit.framework.TestSuite.runTest(TestSuite.java:208)
at junit.framework.TestSuite.run(TestSuite.java:203)
at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)
Caused by: User is not mapped.
at org.hibernate.hql.ast.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:85)
at org.hibernate.hql.ast.FromElementFactory.addFromElement(FromElementFactory.java:77)
at org.hibernate.hql.ast.FromClause.addFromElement(FromClause.java:67)
at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:217)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:2830)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:2719)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:513)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:371)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:201)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:151)
at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:189)
... 28 more
原因：
hibernate.cfg.xml映射.<mapping resource=""/>的配置
类似原因还可能有：
hql是写的是table名，不是POJO对象