java - Struts 2 Json 结果 Hibernate LazyInitialization - 如何在 hibernate session 中反序列化

Question

我正在尝试实现一个 Hibernate session /事务拦截器，以避免在 Struts2 中对 json 结果产生 LazyInitializationException，但无论如何我都会遇到此异常:

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

我的拦截器看起来像这样:

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，我在 trans.commit() 和 session.close(); 之前就得到了 LazyInitializationException

Answer 1

不要重新实现weel。如果您需要在 View 概念中实现打开 session ，请使用 Hibernate Full Plugin .如果您想修复 LazyInitializationException，请将 FetchType.EAGER 放入集合中。