日期:2014-05-17  浏览次数:20750 次

求救:Unable to intantiate Action!
本人新手,在学struts2,在提交表单后总是抛出java.lang.InstantiationException异常。
jsp页面如下:
HTML code
<%@ page language="java" contentType="text/html; charset=gbk"
    pageEncoding="gbk"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
    <head>
        <meta http-equiv="Content-Type"
            content="text/html; charset=ISO-8859-1">
        <title>Insert title here</title>
    </head>
    <body>
        <s:form action="upload" enctype="multipart/form-data" theme="simple">
            <table border="1" align="center">
                <tr>
                    <td>
                        username:
                    </td>
                    <td>
                        <s:textfield name="username"></s:textfield>
                    </td>
                </tr>
                <tr>
                <td>
                    passwors:
                </td>
                <td>
                    <s:password name="password"></s:password>
                </td>
                </tr>
                <tr>
                <td>
                    file:
                </td>
                <td>
                    <s:file name="file"></s:file>
                </td>
                </tr>
                <tr>
                <td>
                    <s:submit value="submit"></s:submit>
                </td>
                <td>
                    <s:reset value="reset"></s:reset>
                </td>
                </tr>
            </table>
        </s:form>
    </body>
</html>

action代码如下:
Java code
package com.test.action;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public abstract class UploadAction extends ActionSupport {
    private String username;
    private String password;
    private File file;
    private String fileFileName;
    private String fileContentType;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public File getFile() {
        return file;
    }
    public void setFile(File file) {
        this.file = file;
    }
    public String getFileFileName() {
        return fileFileName;
    }
    public void setFileFileName(String fileFileName) {
        this.fileFileName = fileFileName;
    }
    public String getFileContentType() {
        return fileContentType;
    }
    public void setFileContentType(String fileContentType) {
        this.fileContentType = fileContentType;
    }
    public String execute()throws Exception
    {
        InputStream is = new FileInputStream(file);
        String root = ServletActionContext.getRequest().getRealPath("/upload");
        
        Fil