简单Struts问题？

<logic:present name="personbean" scope="request">
<bean:write name="personbean" property="userName" />!
</logic:present>
一样的

那应该两个name都是属于模型组件PersonBean了，是一样的,以吧。

不过多了一层保证，本来他会在各个生命周期里面找这个name为personbean的对象

看看我下面这个为什么出不来呢？
hello.jsp
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %><html:html locale="true">
  <head>
    <title><bean:message key="hello.jsp.title"/></title>
    <html:base/>
  </head>
  <body bgcolor="white"><p>    <h2><font color="#FF0000">
<bean:message key="hello.jsp.body" /></font><br><hr>
<bean:message key="hello.jsp.page.heading"/></h2><p>   <html:errors/><p>    <logic:present name="PersonBean" scope="request">
       <h2>
     <bean:write name="PersonBean" property="userName"/>!<p>
         <bean:write name="PersonBean" property="passWord"/>!<p>
       </h2>
    </logic:present>
    <html:form action="/HelloWorld.do" focus="userName" >      <bean:message key="hello.jsp.prompt.person"/><br>
      <html:text property="userName" size="16" maxlength="16"/><br>
  <bean:message key="hello.jsp.prompt.password"/><br>
      <html:password property="passWord" size="16" maxlength="16"/><br>
      <html:submit property="submit" value="Submit"/>
      <html:reset/>    </html:form><br>  </body>
</html:html>

package helloapp;import javax.servlet.http.HttpServletRequest;import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionMapping;public final class HelloForm extends ActionForm {    private String userName = null;
    private String passWord = null;    public String getUserName() {
        return (this.userName);
    }    public void setUserName(String userName) {
        this.userName = userName;
    }    public void reset(ActionMapping mapping, HttpServletRequest request) {
        this.userName = null;
    }
    public ActionErrors validate(ActionMapping mapping,
                                 HttpServletRequest request) {        ActionErrors errors = new ActionErrors();        if ((userName == null) || (userName.length() < 1))
            errors.add("username", new ActionMessage("hello.no.username.error"));          if ((passWord == null) || (passWord.length() < 1))
            errors.add("password", new ActionMessage("hello.no.username.error"));
        return errors;
    }
  public String getPassWord()
  {
    return passWord;
  }
  public void setPassWord(String passWord)
  {
    this.passWord = passWord;
  }
}

package helloapp;import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletResponse;import org.apache.struts.action.Action;
import org.apache.struts.action.ActionMessage;
import org.apache.struts.action.ActionMessages;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.util.MessageResources;public final class HelloAction extends Action {    public ActionForward execute(ActionMapping mapping,
                                 ActionForm form,
                                 HttpServletRequest request,
                                 HttpServletResponse response)
    throws Exception {        // These "messages" come from the ApplicationResources.properties file
        MessageResources messages = getResources(request);        /*
         * Validate the request parameters specified by the user
         * Note: Basic field validation done in HelloForm.java
         *       Business logic validation done in HelloAction.java
         */
        ActionMessages errors = new ActionMessages();
        String userName = (String)((HelloForm) form).getUserName();
        String passWord = (String)((HelloForm)form).getPassWord();
        String badUserName = "Monster";        if (userName.equalsIgnoreCase(badUserName)) {
           errors.add("username", new ActionMessage("hello.dont.talk.to.monster", badUserName ));
           saveErrors(request, errors);
           return (new ActionForward(mapping.getInput()));
        }
        PersonBean pb = new PersonBean();
        pb.setUserName(userName);
        pb.setPassWord(passWord);
        request.setAttribute("personbean",pb.getUserName());
        request.setAttribute("password",pb.getPassWord());
        // Remove the Form Bean - don't need to carry values forward
        request.removeAttribute(mapping.getAttribute());        // Forward control to the specified success URI
        return (mapping.findForward("SayHello"));    }
}

request.setAttribute("personbean",pb.getUserName());
改成
request.setAttribute("personbean",pb);

我顶！中国IT人才网( http://www.itbbs.net.cn )!中国IT人才网( http://www.itbbs.net.cn )!中国IT人才网( http://www.itbbs.net.cn )!中国IT人才网( http://www.itbbs.net.cn )!中国IT人才网( http://www.itbbs.net.cn )!中国IT人才网( http://www.itbbs.net.cn )!中国IT人才网( http://www.itbbs.net.cn )!中国IT人才网( http://www.itbbs.net.cn )!中国IT人才网( http://www.itbbs.net.cn )!中国IT人才网( http://www.itbbs.net.cn )!中国IT人才网( http://www.itbbs.net.cn )!
免费招聘、求职。IT人工作的天堂。希望能够为大家所用。

request.setAttribute("personbean",pb.getUserName());
改成
request.setAttribute("personbean",pb);为什么，难道不一样吗？

<bean:write name="PersonBean" property="userName"/>
这是个对象，personBean里面有这个userName的属性，你那个只是一个字符对象而已
^_^，结贴啊，你在广州吗

根本不能这个问题，我改了一样的。
照理说，request.setAttribute("personbean",pb.getUserName());
没有错误把pb.getUserName()放入名字为personbean里。

难道这里的personbean
request.setAttribute("PersonBean",pb);
request.setAttribute("PersonBean",pb);
要跟这里的personbean对住 <logic:present name="PersonBean" scope="request">
       <h2>
     <bean:write name="PersonBean" property="userName"/>!<p>
         <bean:write name="PersonBean" property="passWord"/>!<p>
       </h2>
    </logic:present>那为什么我如果不填内容，提交上去会出错，不会执行ActionForm里的 if ((userName == null) || (userName.length() < 1))
            errors.add("username", new ActionMessage("hello.no.username.error"));          if ((passWord == null) || (passWord.length() < 1))
            errors.add("password", new ActionMessage("hello.no.username.error"));
        return errors;

我看了，但还是不太理解？能否解释一下， classjava(原始野人)

request.setAttribute("personbean",pb.getUserName());
改成
request.setAttribute("personbean",pb);
request.setAttribute("userName",pb.getUserName());

现在可以了，我觉得是这个原因。在request.setAttribute("key",name)
这里也要改成。
<logic:present name="key" scope="request">
       <h2>
     <bean:write name="key" property="userName"/>!<p>
         <bean:write name="key" property="passWord"/>!<p>
       </h2>
    </logic:present>是不是这样的，反正我是这样调试出来的。

那为什么我如果不填内容，提交上去会出错，不会执行ActionForm里的 if ((userName == null) || (userName.length() < 1))
            errors.add("username", new ActionMessage("hello.no.username.error"));          if ((passWord == null) || (passWord.length() < 1))
            errors.add("password", new ActionMessage("hello.no.username.error"));
        return errors;

现在可以了，我觉得是这个原因。在request.setAttribute("key",name) //这个地方的name应该是一个FormObject, 不应该是单个文本框，后面的才有效
<logic:present name="key" scope="request">
       <h2>
     <bean:write name="key" property="userName"/>!<p>
         <bean:write name="key" property="passWord"/>!<p>
       </h2>
    </logic:present>

调试易

简单Struts问题？

解决方案 »