Struts 2 Json Result Hibernate LazyInitialization - 如何在休眠会话中反序列化 [英] Struts 2 Json Result Hibernate LazyInitialization - How to deserialize within a hibernate session
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问题描述
我正在尝试实现 Hibernate 会话/事务拦截器以避免 LazyInitializationException on json 结果导致 Struts2，但我还是得到了这个异常:
I'm trying to implement a Hibernate session/transaction interceptor to avoid LazyInitializationException on json results in Struts2, but I get this exception anyway:
245968 [http-8080-7] ERROR util.HibernateEndTransInterceptor - org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.reflect.InvocationTargetException
org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.reflect.InvocationTargetException
at org.apache.struts2.json.JSONWriter.bean(JSONWriter.java:238)
at org.apache.struts2.json.JSONWriter.processCustom(JSONWriter.java:171)
at org.apache.struts2.json.JSONWriter.process(JSONWriter.java:161)
at org.apache.struts2.json.JSONWriter.value(JSONWriter.java:127)
at org.apache.struts2.json.JSONWriter.write(JSONWriter.java:95)
at org.apache.struts2.json.JSONUtil.serialize(JSONUtil.java:116)
at org.apache.struts2.json.JSONResult.createJSONString(JSONResult.java:196)
at org.apache.struts2.json.JSONResult.execute(JSONResult.java:170)
at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:374)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:278)
at util.HibernateEndTransInterceptor.intercept(HibernateEndTransInterceptor.java:55)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:176)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265)
at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:236)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:236)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:190)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:75)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:90)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:243)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171)
at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:176)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:192)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:187)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at util.HibernateBeginTransInterceptor.intercept(HibernateBeginTransInterceptor.java:32)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at util.LoginInterceptor.intercept(LoginInterceptor.java:36)
at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:249)
at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:511)
at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:831)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:652)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1203)
at java.lang.Thread.run(Thread.java:722)
Caused by: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.reflect.InvocationTargetException
at org.apache.struts2.json.JSONWriter.bean(JSONWriter.java:238)
at org.apache.struts2.json.JSONWriter.processCustom(JSONWriter.java:171)
at org.apache.struts2.json.JSONWriter.process(JSONWriter.java:161)
at org.apache.struts2.json.JSONWriter.value(JSONWriter.java:127)
at org.apache.struts2.json.JSONWriter.add(JSONWriter.java:363)
at org.apache.struts2.json.JSONWriter.bean(JSONWriter.java:223)
... 73 more
Caused by: org.apache.struts2.json.JSONException: org.apache.struts2.json.JSONException: java.lang.reflect.InvocationTargetException
at org.apache.struts2.json.JSONWriter.bean(JSONWriter.java:238)
at org.apache.struts2.json.JSONWriter.processCustom(JSONWriter.java:171)
at org.apache.struts2.json.JSONWriter.process(JSONWriter.java:161)
at org.apache.struts2.json.JSONWriter.value(JSONWriter.java:127)
at org.apache.struts2.json.JSONWriter.add(JSONWriter.java:363)
at org.apache.struts2.json.JSONWriter.bean(JSONWriter.java:223)
... 78 more
Caused by: org.apache.struts2.json.JSONException: java.lang.reflect.InvocationTargetException
at org.apache.struts2.json.JSONWriter.bean(JSONWriter.java:238)
at org.apache.struts2.json.JSONWriter.processCustom(JSONWriter.java:171)
at org.apache.struts2.json.JSONWriter.process(JSONWriter.java:161)
at org.apache.struts2.json.JSONWriter.value(JSONWriter.java:127)
at org.apache.struts2.json.JSONWriter.add(JSONWriter.java:363)
at org.apache.struts2.json.JSONWriter.bean(JSONWriter.java:223)
... 83 more
Caused by: java.lang.reflect.InvocationTargetException
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.apache.struts2.json.JSONWriter.bean(JSONWriter.java:218)
... 88 more
Caused by: org.hibernate.LazyInitializationException: could not initialize proxy - no Session
at org.hibernate.proxy.AbstractLazyInitializer.initialize(AbstractLazyInitializer.java:165)
at org.hibernate.proxy.AbstractLazyInitializer.getImplementation(AbstractLazyInitializer.java:272)
at org.hibernate.proxy.pojo.javassist.JavassistLazyInitializer.invoke(JavassistLazyInitializer.java:185)
at com.lm.model.common.Language_$$_javassist_0.getName(Language_$$_javassist_0.java)
... 93 more
我的拦截器如下所示:
package util;
import java.util.Map;
import org.apache.log4j.Logger;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import util.hibernate.HibernateUtil;
import com.lm.action.ActionsConstants;
import com.lm.action.user.Constants;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.Interceptor;
public class HibernateEndTransInterceptor implements Interceptor, Constants, ActionsConstants {
private static final long serialVersionUID = -8734958511612355789L;
private static SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
private transient Logger log = Logger.getLogger(HibernateEndTransInterceptor.class);
private Session s=null;
private Transaction t=null;
@Override
public void destroy() {
}
@Override
public void init() {
}
@Override
public String intercept(final ActionInvocation invocation) throws Exception {
/*invocation.addPreResultListener(new PreResultListener() {
@Override
public void beforeResult(ActionInvocation arg0, String arg1) {
Map<String, ResultConfig> resultsMap = invocation.getProxy().getConfig().getResults();
//ResultConfig finalResultConfig = resultsMap.get(resultCode);
}
});*/
Map<String,Object> strutsSession = invocation.getInvocationContext().getSession();
String res=null;
try {
s=sessionFactory.openSession();
t = s.beginTransaction();
strutsSession.put("hibernateSession", s);
strutsSession.put("hibernateTransaction", t);
res=invocation.invoke();
t.commit();
} catch (Throwable t2) {
log.error(t2,t2);
try {
t.rollback();
} catch (Throwable t3) {
log.error(t3,t3);
}
} finally {
try {
s.close();
} catch (Throwable t) {
log.error(t,t);
}
strutsSession.remove("hibernateSession");
strutsSession.remove("hibernateTransaction");
}
return res;
}
}
这不起作用，我什至在 trans.commit() 和 session.close(); 之前得到了 LazyInitializationExceptionp>
This is not working, I'm getting LazyInitializationException even before trans.commit() and session.close();
推荐答案
好的，我终于解决了将泛型 DAO(带有会话和事务)注入到 genericAction 的问题.这适用于 JSONResults &带有惰性休眠 bean 的 jsp.
Ok, finally I've solved adding injection of generic DAO (with session and transaction) to a genericAction. This works for JSONResults & jsp's with lazy hibernate beans.
感谢对bmorris591"和Roman C"的贡献(我不想要，甚至不需要所有这些插件).
Thanks for contributions to "bmorris591" and "Roman C" (I don't want, even need, all this plugin).
我留下我的例子，我希望我不会忘记任何事情......
I leave my examples, I hope I don't forget anything...
拦截器配置(struts.xml片段):
Interceptor configuration (struts.xml fragment):
<package name="lmp" extends="struts-default,json-default">
<interceptors>
<interceptor name="login" class="util.LoginInterceptor"/>
<interceptor name="hibernateSessionTransInjector" class="util.HibernateSessionTransInjectorInterceptor"/>
<interceptor-stack name="loggingStack">
<interceptor-ref name="login" />
<interceptor-ref name="defaultStack" />
<interceptor-ref name="hibernateSessionTransInjector"/>
</interceptor-stack>
</interceptors>
<default-interceptor-ref name="loggingStack"/>
<global-results>
<result name="login" type="redirectAction">login</result>
</global-results>
</package>
<package name="myAction" extends="lmp">
<action name="myAction" class="com.lmp.MyAction">
<result name="json" type="json">
<param name="ignoreHierarchy">false</param>
</result>
<result name="*">/jsp/myAction.jsp</result>
</action>
</package>
拦截器实现:
package util;
import org.apache.log4j.Logger;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import util.hibernate.HibernateUtil;
import com.lm.action.ActionsConstants;
import com.lm.action.user.Constants;
import com.lm.dao.DAO;
import com.opensymphony.xwork2.ActionInvocation;
import com.opensymphony.xwork2.interceptor.Interceptor;
public class HibernateSessionTransInjectorInterceptor implements Interceptor, Constants, ActionsConstants {
private static final long serialVersionUID = -8734958511612355789L;
private static SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
private transient Logger log = Logger.getLogger(HibernateSessionTransInjectorInterceptor.class);
@Override
public void destroy() {
}
@Override
public void init() {
}
@Override
public String intercept(final ActionInvocation invocation) throws Exception {
String res=null;
DAO dao=null;
try {
Session s=sessionFactory.openSession();
dao = new DAO(s);
dao.beginTransaction();
**invocation.getStack().setValue("dao", dao, true);**
res=invocation.invoke();
boolean rollback=(Boolean)invocation.getStack().findValue("rollbackTransaction", Boolean.class);
if (rollback)
dao.rollBackTransaction();
if (!dao.getT().wasRolledBack())
dao.commitTransaction();
} catch (Throwable t2) {
log.error(t2,t2);
if (dao!=null)
try {
dao.rollBackTransaction();
} catch (Throwable t3) {
log.error(t3,t3);
}
} finally {
if (dao!=null)
try {
dao.finallyClose();
} catch (Throwable t) {
log.error(t,t);
}
}
return res;
}
}
UserDAO 示例:
UserDAO example:
public class UserDAO extends DAO {
[...]
public UserDAO(Session s) {
super(s);
}
[...]
}
GenericDAO 示例:
GenericDAO example:
public class DAO {
protected static final transient Logger log = Logger.getLogger(DAO.class);
public static SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
public Session s = null;
public Transaction t = null;
public DAO(Session s) {
this.s=s;
}
public void beginTransaction(Transaction t) {
this.t=t;
}
private int exceptionErr=0;
public void beginTransaction() {
try {
t=s.beginTransaction();
} catch (Throwable t) {
log.error(t,t);
}
}
public void rollBackTransaction() {
if (t!=null && t.isActive())
t.rollback();
}
public void commitTransaction() {
if (t!=null && t.isActive())
t.commit();
}
public void finallyClose() {
if (t!=null && t.isActive())
t.rollback();
if (s!=null && s.isOpen())
s.close();
}
public Session getS() {
return s;
}
public void setS(Session s) {
this.s = s;
}
public Transaction getT() {
return t;
}
public void setT(Transaction t) {
this.t = t;
}
}
通用操作:
public class GenericAction extends ActionSupport {
private DAO dao=null; //Interceptor injects here
public GenericAction() {
}
...
@JSON(deserialize=false, serialize=false)
public DAO getDao() {
return dao;
}
@JSON(deserialize=false, serialize=false)
public void setDao(DAO dao) {
this.dao = dao;
}
}
我的行动:
public class MyAction extends GenericAction {
public MyAction() {
}
@Override
public String execute() throws Exception {
super.execute();
UserDAO userDAO=new UserDAO(getDao().getS());
OtherDAO otherDAO=new OtherDAO(getDao().getS());
userDAO.loadUsers(...);
return SUCCESS;
}
}
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