org.springframework.dao.InvalidDataAccessApiUsageException: org.hibernate.hql.ast.QuerySyntaxException: Article is not mapped [Select count(article.id) from Article article]; nested exception is java.lang.IllegalArgumentException: org.hibernate.hql.ast.QuerySyntaxException: Article is not mapped [Select count(article.id) from Article article] at org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:271) at org.springframework.orm.jpa.vendor.HibernateJpaDialect.translateExceptionIfPossible(HibernateJpaDialect.java:97) at org.springframework.dao.support.DataAccessUtils.translateIfNecessary(DataAccessUtils.java:212) at org.springframework.orm.jpa.JpaAccessor.translateIfNecessary(JpaAccessor.java:152) at org.springframework.orm.jpa.JpaTemplate.execute(JpaTemplate.java:189) at org.springframework.orm.jpa.JpaTemplate.executeFind(JpaTemplate.java:151) at org.springframework.orm.jpa.JpaTemplate.find(JpaTemplate.java:311) at org.springframework.orm.jpa.JpaTemplate.find(JpaTemplate.java:307) at org.lee.weixin.dao.impl.ArticleDaoImpl.countArticle(ArticleDaoImpl.java:49) at org.lee.weixin.service.impl.ArticleServiceImpl.countArticle(ArticleServiceImpl.java:36) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:198) at $Proxy14.countArticle(Unknown Source) at org.lee.weixin.action.FetchArticlesServlet.doPost(FetchArticlesServlet.java:33) at org.lee.weixin.action.FetchArticlesServlet.doGet(FetchArticlesServlet.java:21) at javax.servlet.http.HttpServlet.service(HttpServlet.java:620) at javax.servlet.http.HttpServlet.service(HttpServlet.java:727) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:722) Caused by: java.lang.IllegalArgumentException: org.hibernate.hql.ast.QuerySyntaxException: Article is not mapped [Select count(article.id) from Article article] at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:601) at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:96) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:358) at $Proxy15.createQuery(Unknown Source) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:601) at org.springframework.orm.jpa.JpaTemplate$CloseSuppressingInvocationHandler.invoke(JpaTemplate.java:404) at $Proxy16.createQuery(Unknown Source) at org.springframework.orm.jpa.JpaTemplate$9.doInJpa(JpaTemplate.java:313) at org.springframework.orm.jpa.JpaTemplate.execute(JpaTemplate.java:184) ... 36 more Caused by: org.hibernate.hql.ast.QuerySyntaxException: Article is not mapped [Select count(article.id) from Article article] at org.hibernate.hql.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:181) at org.hibernate.hql.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:110) at org.hibernate.hql.ast.tree.FromClause.addFromElement(FromClause.java:93) at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:277) at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3056) at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:2945) at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:688) at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:544) at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:281) at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:229) at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:251) at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:183) at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:134) at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:101) at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:80) at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:94) at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:156) at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:135) at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1650) at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:93) ... 50 more
说明对象和实体之间映射出问题。
修改方法：在实体类头部加上：
@Entity @Table (name="ARTICLE")