iteye_5917 2011-04-03 23:09
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已采纳

Struts2类型转换器出了一个NullPointerException,那位大哥指点一下

LoginAction.java

package login;

import com.opensymphony.xwork2.Action;

public class LoginAction implements Action{
    
    private User user;

    private String tip;

    public String getTip() {
        return tip;
    }

    public void setTip(String tip) {
        this.tip = tip;
    }

    public String execute() throws Exception {
        
        if (getUser().getUsername().equals("123") && getUser().getPassword().equals("123")) {
            this.setTip("转化成功");
            return Action.SUCCESS;
        } else {
            this.setTip("转化失败");
            return Action.ERROR;
        }
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }
}

UserConverter.java

package login;

import java.util.Map;

import ognl.DefaultTypeConverter;

public class UserConverter extends DefaultTypeConverter {


    public Object convertValue(Map context, Object value, Class toType) {
        if (toType == User.class) {
            String[] params = (String[])value;
            User user = new User();
            String[] userValues = params[0].split(",");
            user.setUsername(userValues[0]);
            user.setPassword(userValues[1]);
            return user;
        } else if (toType == String.class){
            User user = (User)value;
            return "<" + user.getUsername() + "," + user.getPassword() + ">";
            
        }
        return null;
    }

}

Login.jsp

<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%>
<%@ taglib prefix="s" uri="/struts-tags" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>登陆页面</title>
  </head>
  
  <body>
    <s:form action="Login">
        <table align="center">
        <caption><h3>用户登陆</h3></caption>
            <tr>
                <td><s:textfield name="namepass" label="用户名和密码"/></td>
            </tr>
            <tr align="center">
                <td><s:submit value="登录"/></td>
            </tr>
        </table>
    </s:form>
  </body>
</html>

LoginAction-conversion.properties

user=login.UserConverter

struts.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC 
    "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
    "http://struts.apache.org/dtds/struts-2.0.dtd">
    
    
<struts>
    <package name="strutsqs" extends="struts-default">

        <action name="Login" class="login.LoginAction">
            <result name="success">/welcome.jsp</result>
        </action>
        
        
    </package>
</struts>

在Login.jsp页面中输入123,123，会出现下面的异常，各位大哥指点迷津

java.lang.NullPointerException
    login.LoginAction.execute(LoginAction.java:21)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    java.lang.reflect.Method.invoke(Unknown Source)
    com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:404)
    com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:267)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:229)
    com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:221)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:150)
    org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:48)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:123)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:167)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:105)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:83)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:207)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:74)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:127)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:107)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:206)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:115)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:143)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:121)
    com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:170)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:123)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:50)
    org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:504)
    org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:419)
  • 写回答

1条回答 默认 最新

  • cheng888qi 2011-04-04 11:09
    关注

    [quote][/quote]
    改成
    [code="html"]

    [/code]
    试试

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
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