我正在使用 Jersey 实现一个 Restful Web 服务。我有一个使用休眠将数据映射到数据库的包。我是使用 DAO 休眠的新手:
我在 GenericDao 类中有一个方法:
public abstract class GenericDAO<T> extends DAOFactory {
private final Class classe;
public GenericDAO(Class classe) {
this.classe = classe;
}
public List<T> findByCriteria(List<Criterion> list) throws Exception {
Criteria criteria = getSession().createCriteria(classe);
for (int i = 0; i < list.size(); i++)
criteria.add(list.get(i));
return criteria.list();
}
}
然后我有我的 DAO 类,如:
public class TaskDAO extends GenericDAO<Task> {
public TaskDAO() {
super(Task.class);
}
}
然后我在服务类中使用这个方法,它工作得很好,如下所示:
public Response get(long projectId, String username) {
List<Criterion> list = new ArrayList<Criterion>();
Criterion c = Restrictions.eq("project.id", projectId);
list.add(c);
List<Deliverable> deliverables = deliverableDAO.findByCriteria(list);
return deliverables
}
问题出在另一个 Service 类中的这个方法中:
public Response get(String username) {
List<Criterion> list = new ArrayList<Criterion>();
Criterion c = Restrictions.eq("user.username", username);
list.add(c);
List<Task> tasks = taskDAO.findByCriteria(list);
return tasks;
}
如您所见,“Restrictions.eq("project.id", projectId)" 对我来说很好,但是“Restrictions.eq("user.username", username)" 可能与 'user.username' 有问题,有
什么帮助吗?
堆栈跟踪中的错误如下:
javax.ws.rs.WebApplicationException: org.hibernate.QueryException: could not resolve property: user.username of: se.softwerk.timelog.model.Task
at se.softwerk.controller.services.TaskService.get(TaskService.java:29)
at se.softwerk.timelog.controller.TaskManager.taskList(TaskManager.java:72)
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 com.sun.jersey.spi.container.JavaMethodInvokerFactory$1.invoke(JavaMethodInvokerFactory.java:60)
at com.sun.jersey.server.impl.model.method.dispatch.AbstractResourceMethodDispatchProvider$ResponseOutInvoker._dispatch(AbstractResourceMethodDispatchProvider.java:205)
at com.sun.jersey.server.impl.model.method.dispatch.ResourceJavaMethodDispatcher.dispatch(ResourceJavaMethodDispatcher.java:75)
at com.sun.jersey.server.impl.uri.rules.HttpMethodRule.accept(HttpMethodRule.java:288)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.ResourceClassRule.accept(ResourceClassRule.java:108)
at com.sun.jersey.server.impl.uri.rules.RightHandPathRule.accept(RightHandPathRule.java:147)
at com.sun.jersey.server.impl.uri.rules.RootResourceClassesRule.accept(RootResourceClassesRule.java:84)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1469)
at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1400)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1349)
at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1339)
at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:416)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:537)
at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:708)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:928)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:539)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:298)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: org.hibernate.QueryException: could not resolve property: user.username of: se.softwerk.timelog.model.Task
at org.hibernate.persister.entity.AbstractPropertyMapping.propertyException(AbstractPropertyMapping.java:83)
at org.hibernate.persister.entity.AbstractPropertyMapping.toColumns(AbstractPropertyMapping.java:98)
at org.hibernate.persister.entity.BasicEntityPropertyMapping.toColumns(BasicEntityPropertyMapping.java:61)
at org.hibernate.persister.entity.AbstractEntityPersister.toColumns(AbstractEntityPersister.java:1801)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getColumns(CriteriaQueryTranslator.java:522)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.findColumns(CriteriaQueryTranslator.java:537)
at org.hibernate.criterion.SimpleExpression.toSqlString(SimpleExpression.java:66)
at org.hibernate.loader.criteria.CriteriaQueryTranslator.getWhereCondition(CriteriaQueryTranslator.java:419)
at org.hibernate.loader.criteria.CriteriaJoinWalker.<init>(CriteriaJoinWalker.java:123)
at org.hibernate.loader.criteria.CriteriaJoinWalker.<init>(CriteriaJoinWalker.java:92)
at org.hibernate.loader.criteria.CriteriaLoader.<init>(CriteriaLoader.java:93)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1464)
at org.hibernate.internal.CriteriaImpl.list(CriteriaImpl.java:374)
at se.softwerk.timelog.model.dao.GenericDAO.findByCriteria(GenericDAO.java:33)
at se.softwerk.controller.services.TaskService.get(TaskService.java:24)