该程序的主要代码,我引用网友的,并做了一些改进.上这个帖子的原因之一,是为了修正之前自己的一些误解.
概述:
一些网友,包括我,也曾经试图通过 input type 为 file的控件,获取其文件的完整路径.后来我发现行不通,这也许是web设计者的事,本来这个控件就是用来上传用的,所以,在前端,可以通过 input type='file'的控件将待上传的文件包装起来,然后通过请求,以流的形式将请求发送给服务器端,然后服务器端通过获取请求对应的流进行处理,然后往服务器端写文件.
一下是源码:
首先上贴客户端代码:
<html>
<head>
<title>前台-接收文件</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<form name="frm" method="post" action="handleFile.jsp"
ENCTYPE="multipart/form-data">
<input type="file" name="filept">
<br />
<br />
<input type="submit" name="submit" value="上传">
</form>
</body>
</html>
然后定义一个'上传文件类' - JspFileUpload,用来上传从客户端发送的文件:
package spt.uploader; import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Hashtable;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest; /**JSP上传文件类
* @author Administrator
*2015-1-3
*/
public class JspFileUpload {
/** request对象 */
private HttpServletRequest request = null;
/** 上传文件的路径 */
private String uploadPath = null;
/** 每次读取得字节的大小 */
private static int BUFSIZE = 1024 * 8;
/** 存储参数的Hashtable */
private Hashtable paramHt = new Hashtable();
/** 存储上传的文件的文件名的ArrayList */
private ArrayList updFileArr = new ArrayList(); /**
* 设定request对象.
*
* @param request
* HttpServletRequest request对象.
*/
public void setRequest(HttpServletRequest request) {
this.request = request;
} /**
* 设定文件上传路径。
*
* @param path
* 用户指定的文件的上传路径。
*/
public void setUploadPath(String path) {
this.uploadPath = path;
} /**
* 文件上传处理主程序。
*
* @return int 操作结果 0 文件操作成功；1 request对象不存在。 2 没有设定文件保存路径或者文件保存路径不正确；3
* 没有设定正确的enctype；4 文件操作异常。
*/
public int process() {
int status = 0;
// 文件上传前，对request对象，上传路径以及enctype进行check.
status = preCheck();
// 出错的时候返回错误代码.
if (status != 0)
return status;
try {
// 参数或者文件名
String name = null;
// 参数的value
String value = null;
// 读取的流是否为文件的标志位
boolean fileFlag = false;
// 要存储的文件。
File tmpFile = null;
// 上传的文件的名字
String fName = null;
FileOutputStream baos = null;
BufferedOutputStream bos = null;
//存储参数的Hashtable
paramHt = new Hashtable();
updFileArr = new ArrayList();
int rtnPos = 0;
byte[] buffs = new byte[BUFSIZE * 8];
//取得ContentType
String contentType = request.getContentType();
int index = contentType.indexOf("boundary=");
String boundary = "--" + contentType.substring(index + 9);
String endBoundary = boundary + "--";
//从request对象中取得流。
ServletInputStream sis = request.getInputStream();
// 读取1行
while ((rtnPos = sis.readLine(buffs, 0, buffs.length)) != -1) {
String strBuff = new String(buffs, 0, rtnPos);
// 读取1行数据.
if (strBuff.startsWith(boundary)) {
if (name != null && name.trim().length() > 0) {
if (fileFlag) {
bos.flush();
baos.close();
bos.close();
baos = null;
bos = null;
updFileArr.add(fName);
} else {
Object obj = paramHt.get(name);
ArrayList al = new ArrayList();
if (obj != null) {
al = (ArrayList) obj;
}
al.add(value);
System.out.println(value);
paramHt.put(name, al);
}
}
name = new String();
value = new String();
fileFlag = false;
fName = new String();
rtnPos = sis.readLine(buffs, 0, buffs.length);
if (rtnPos != -1) {
strBuff = new String(buffs, 0, rtnPos);
if (strBuff.toLowerCase().startsWith("content-disposition: form-data; ")) {
int nIndex = strBuff.toLowerCase().indexOf("name=\"");
int nLastIndex = strBuff.toLowerCase().indexOf("\"", nIndex + 6);
name = strBuff.substring(nIndex + 6, nLastIndex);
}
int fIndex = strBuff.toLowerCase().indexOf("filename=\"");
if (fIndex != -1) {
fileFlag = true;
int fLastIndex = strBuff.toLowerCase().indexOf("\"", fIndex + 10);
fName = strBuff.substring(fIndex + 10, fLastIndex);
fName = getFileName(fName);
if (fName == null || fName.trim().length() == 0) {
fileFlag = false;
sis.readLine(buffs, 0, buffs.length);
sis.readLine(buffs, 0, buffs.length);
sis.readLine(buffs, 0, buffs.length);
continue;
} else {
fName = getFileNameByTime(fName);
sis.readLine(buffs, 0, buffs.length);
sis.readLine(buffs, 0, buffs.length);
}
}
}
} else if (strBuff.startsWith(endBoundary)) {
if (name != null && name.trim().length() > 0) {
if (fileFlag) {
bos.flush();
baos.close();
bos.close();
baos = null;
bos = null;
updFileArr.add(fName);
} else {
Object obj = paramHt.get(name);
ArrayList al = new ArrayList();
if (obj != null) {
al = (ArrayList) obj;
}
al.add(value);
paramHt.put(name, al);
}
}
} else {
if (fileFlag) {
if (baos == null && bos == null) {
tmpFile = new File(uploadPath + fName);
baos = new FileOutputStream(tmpFile);
bos = new BufferedOutputStream(baos);
}
bos.write(buffs, 0, rtnPos);
baos.flush();
} else {
System.out.println("test :" + value + "--" + strBuff);
value = value + strBuff;
}
}
}
} catch (IOException e) {
status = 4;
}
return status;
} private int preCheck() {
int errCode = 0;
if (request == null) //不存在请求.
return 1;
if (uploadPath == null || uploadPath.trim().length() == 0) //上传文件路径错误.
return 2;
else {
File tmpF = new File(uploadPath);
if (!tmpF.exists())
return 2;
}
String contentType = request.getContentType();
if (contentType.indexOf("multipart/form-data") == -1)
return 3;
return errCode;
} public String getParameter(String name) {
String value = "";
if (name == null || name.trim().length() == 0)
return value;
value = (paramHt.get(name) == null) ? "" : (String) ((ArrayList) paramHt.get(name)).get(0);
return value;
} public String[] getParameters(String name) {
if (name == null || name.trim().length() == 0)
return null;
if (paramHt.get(name) == null)
return null;
ArrayList al = (ArrayList) paramHt.get(name);
String[] strArr = new String[al.size()];
for (int i = 0; i < al.size(); i++)
strArr[i] = (String) al.get(i);
return strArr;
} public int getUpdFileSize() {
return updFileArr.size();
} public String[] getUpdFileNames() {
String[] strArr = new String[updFileArr.size()];
for (int i = 0; i < updFileArr.size(); i++)
strArr[i] = (String) updFileArr.get(i);
return strArr;
} private String getFileName(String input) {
int fIndex = input.lastIndexOf("\\");
if (fIndex == -1) {
fIndex = input.lastIndexOf("/");
if (fIndex == -1) {
return input;
}
}
input = input.substring(fIndex + 1);
return input;
} private String getFileNameByTime(String input) {
int index = input.indexOf(".");
Date dt = new Date();
SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHHmmssSSS");
return input.substring(0, index) + sdf.format(dt) + input.substring(index);
}
}
最后定义一个.jsp文件,用来调用'上传文件类',并处理文件:
<%@ page contentType="text/html; charset=utf-8"%>
<%@ page import="spt.uploader.JspFileUpload"%> <html>
<head>
<title>后台-jsp-处理前端上传的文件.</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
//初始化
JspFileUpload jfu = new JspFileUpload();
//设定request对象
jfu.setRequest(request);
//设定上传文件的目标路径
jfu.setUploadPath("C:\\");
//上传处理
jfu.process();
//取得上传的文件的名字
String[] fileArr = jfu.getUpdFileNames();
//取得上传文件的个数
int fileNumber = jfu.getUpdFileSize();
//下面的是测试输出的代码。
out.println("fileArr size:" + fileArr.length);
if (fileArr.length > 0)
out.println("fileArr 0:" + fileArr[0]);
%>
</body>
</html>