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关于JSP <from enctype="MULTIPART/FORM-DATA"取不到数据的解决方法
自己在项目中,不用别人的开源包,也碰到了这样的情况,在网上查了好多文章,没见到有好的解决方案,特此写出此文章,希望能帮到你.方法如下:
UploadBean.java
package test.servlet;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Hashtable;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
/**
*
*
*
* Title: 文件上传类
*
* Description: 既能对文件进行上传,又能取得输入框的值,最多可同时上传255个文件
*
* Copyright: Copyright (c) 2008
*
* @version 1.0
*
*/
public class UploadBean {
private String[] sourceFile = new String[255]; // 源文件名
private String[] suffix = new String[255]; // 文件后缀名
private String canSuffix = ".gif.jpg.jpeg.png"; // 可上传的文件后缀名
private String objectPath = "c:/"; // 目标文件目录
private String[] objectFileName = new String[255]; // 目标文件名
private ServletInputStream sis = null; // 输入流
private String[] description = new String[255]; // 描述状态
private long size = 100 * 1024; // 限制大小
private int count = 0; // 已传输文件数目
private byte[] b = new byte[4096]; // 字节流存放数组
private boolean successful = true;
private Hashtable fields = new Hashtable();
public UploadBean() {
}
// 设置上传文件的后缀名
public void setSuffix(String canSuffix) {
this.canSuffix = canSuffix;
}
// 设置文件保存路径
public void setObjectPath(String objectPath) {
this.objectPath = objectPath;
}
// 设置文件保存路径
public void setSize(long maxSize) {
this.size = maxSize;
}
// 文件上传处理程序
public void setSourceFile(HttpServletRequest request) throws IOException {
sis = request.getInputStream();
int a = 0;
int k = 0;
String s = "";
while ((a = sis.readLine(b, 0, b.length)) != -1) {
s = new String(b, 0, a);
if ((k = s.indexOf("filename=/"")) != -1) {
// 取得文件数据
s = s.substring(k + 10);
k = s.indexOf("/"");
s = s.substring(0, k);
sourceFile[count] = s;
k = s.lastIndexOf(".");
suffix[count] = s.substring(k + 1);
if (canTransfer(count)) {
transferFile(count);
}
++count;
} else if ((k = s.indexOf("name=/"")) != -1) {
// 普通表单输入元素，获取输入元素名字
String fieldName = s.substring(k + 6, s.length() - 3);
sis.readLine(b, 0, b.length);
StringBuffer fieldValue = new StringBuffer(b.length);
while ((a = sis.readLine(b, 0, b.length)) != -1) {
s = new String(b, 0, a - 2);
if ((b[0] == 45) && (b[1] == 45) && (b[2] == 45)
&& (b[3] == 45) && (b[4] == 45)) {
break;
} else {
fieldValue.append(s);
}
}
fields.put(fieldName, fieldValue.toString());
}
if (!successful)
break;
}
}
// 取得表单元素值
public String getFieldValue(String fieldName) {
if (fields == null || fieldName == null) {
return null;
}
return (String) fields.get(fieldName);
}
// 取得上传文件数
public int getCount() {
return count;
}
// 取得目标路径
public String getObjectPath() {
return objectPath;
}
// 取得源文件名
public String[] getSourceFile() {
return sourceFile;
}
// 取得目标文件名
public String[] getObjectFileName() {
return objectFileName;
}
// 取得上传状态描述
public String[] getDescription() {
return description;
}
// 判断上传文件的类型
private boolean canTransfer(int i) {
suffix[i] = suffix[i].toLowerCase();
// 这个是用来传图片的，各位可以把后缀名改掉或者不要这个条件
if (sourceFile[i].equals("")
|| (!(canSuffix.indexOf("." + suffix[i]) >= 0))) {
description[i] = "ERR: File suffix is wrong.";
return false;
}
else {
return true;
}
}
// 上传文件转换
private void transferFile(int i) {
String x = Long.toString(new java.util.Date().getTime());
try {
objectFileName[i] = x + "." + suffix[i];
FileOutputStream out = new FileOutputStream(objectPath
+ objectFileName[i]);
int a = 0;
int k = 0;
long hastransfered = 0; // 标示已经传输的字节数
String s = "";
while ((a = sis.readLine(b, 0, b.length)) != -1) {
s = new String(b, 0, a);
if ((k = s.indexOf("Content-Type:")) != -1) {
break;
}
}
sis.readLine(b, 0, b.length);
while ((a = sis.readLine(b, 0, b.length)) != -1) {
s = new String(b, 0, a);
if ((b[0] == 45) && (b[1] == 45) && (b[2] == 45)
&& (b[3] == 45) && (b[4] == 45)) {
break;
}
out.write(b, 0, a);
hastransfered += a;
if (hastransfered >= size) {
description[count] = "ERR: The file " + sourceFile[count] +
" is too large to transfer. The whole process is interrupted.";
successful = false;
break;
}
}
if (successful) {
description[count] = "Right: The file " + sourceFile[count] +
" has been transfered successfully.";
}
out.close();
if (!successful) {
sis.close();
File tmp = new File(objectPath + objectFileName[count]);
tmp.delete();
}
}
catch (IOException ioe) {
description[i] = ioe.toString();
}
}
}
--------------------------------------------
<body>
<form action="UploadSubmit.jsp" enctype="MULTIPART/FORM-DATA"
method="post">
作者姓名:
<input type="text" name="Author" />
<br />
公司名称:
<input type="text" name="Company" />
<br />
选择文件1:
<input type="file" name="filename1" />
<br />
选择文件2:
<input type="file" name="filename2" />
<br />
选择文件3:
<input type="file" name="filename3" />
<br />
<input type="submit" value="上载" />
</form>
</body>
-----------------------------------------
UploadSubmit.jsp
<%@ page contentType="text/html;charset=gb2312"%>
<jsp:useBean id="fileBean" scope="page" class="test.servlet.UploadBean" />
<%
fileBean.setObjectPath("D:/Temp");
fileBean.setSize(10000*1024);
fileBean.setSuffix(".gif.jpg.png.jpge");
fileBean.setSourceFile(request);
String [] saSourceFile = fileBean.getSourceFile();
String [] saObjectFile = fileBean.getObjectFileName();
String [] saDescription = fileBean.getDescription();
int iCount = fileBean.getCount();
String sObjectPath = fileBean.getObjectPath();
for(int i=0;i<iCount;i++) {
out.println("<br>源始文件:");
out.println(saSourceFile[i]);
out.println("<br>目标文件:");
out.println(sObjectPath+saObjectFile[i]);
out.println("<br>上传说明:");
out.println(saDescription[i]);
out.println("<br>");
}
out.println("<br>作者:" + fileBean.getFieldValue("Author"));
out.println("<br>公司:" + fileBean.getFieldValue("Company"));
%>
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