请教jsp参数传递的问题------------我只有32分了，不好意思
本文导语: 我要使用jsp来实现文件上载。在真正上载之前，希望可以取回文件名进行一下是否存在的校验。 但是在from中如果指定了ENCTYPE="multipart/form-data" ，使用getParameter就取不会任何参数。 我使用window.location来传递参数，IE5.0...
但是在from中如果指定了ENCTYPE="multipart/form-data" ，使用getParameter就取不会任何参数。
我使用window.location来传递参数，IE5.0无法接收。IE5.5以上可以。
请问还有其他方法可以解决吗？？比如说在action时传递？我试图传递过，结果它println到界面上，而不是作为参数传递了
非常感谢！！
程序如下：
String proc = request.getParameter("proc");
String filename = request.getParameter("filename");
String upload = request.getParameter("upload");
System.out.println("---upload-----upload----" + upload);
System.out.println("---upload-----proc----" + proc)；
int w = 45 ;
%>
Upload a file
function doSubmit()
{
document.form.submit();
return true;
}
function onUpload()
{
alert("---"+ document.form.filename.value);
window.location ="/testupload.jsp?"+"proc=upload1&filename="+ document.form.filename.value;
return true;
}
上载文件
点击"浏览"按键找到你希望上载的本地文件，点击"上载"开始文件上载过程。
|
// Copyright (C) 1998 by Jason Hunter . All rights reserved.
// Use of this class is limited. Please see the LICENSE for more information.
package com.oreilly.servlet;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import java.lang.*;
import javax.servlet.http.*;
/**
* A utility class to handle multipart/form-data requests,
* the kind of requests that support file uploads. This class can
* receive arbitrarily large files (up to an artificial limit you can set),
* and fairly efficiently too.
* It cannot handle nested data (multipart content within multipart content)
* or internationalized content (such as non Latin-1 filenames).
*
* It's used like this:
*
* MultipartRequest multi = new MultipartRequest(req, ".");
*
* out.println("Params:");
* Enumeration params = multi.getParameterNames();
* while (params.hasMoreElements()) {
* String name = (String)params.nextElement();
* String value = multi.getParameter(name);
* out.println(name + " = " + value);
* }
* out.println();
*
* out.println("Files:");
* Enumeration files = multi.getFileNames();
* while (files.hasMoreElements()) {
* String name = (String)files.nextElement();
* String filename = multi.getFilesystemName(name);
* String type = multi.getContentType(name);
* File f = multi.getFile(name);
* out.println("name: " + name);
* out.println("filename: " + filename);
* out.println("type: " + type);
* if (f != null) {
* out.println("f.toString(): " + f.toString());
* out.println("f.getName(): " + f.getName());
* out.println("f.exists(): " + f.exists());
* out.println("f.length(): " + f.length());
* out.println();
* }
* }
*
*
* A client can upload files using an HTML form with the following structure.
* Note that not all browsers support file uploads.
*
* <FORM ACTION="/servlet/Handler/index.html" METHOD=POST
* ENCTYPE="multipart/form-data">
* What is your name? <INPUT TYPE=TEXT NAME=submitter> <BR>
* Which file to upload? <INPUT TYPE=FILE NAME=file> <BR>
* <INPUT TYPE=SUBMIT>
* </FORM>
*
*
* The full file upload specification is contained in experimental RFC 1867,
* available at
* http://www.ietf.org/rfc/rfc1867.txt.
*
* @author Jason Hunter, Copyright © 1998-1999
* @version 1.6, 00/03/19, better WebSphere 2.x/3.x content type workaround
* @version 1.5, 00/02/04, added auto MacBinary decoding for IE on Mac
* @version 1.4, 00/01/05, added getParameterValues(),
* WebSphere 2.x getContentType() workaround,
* stopped writing empty "unknown" file
* @version 1.3, 99/12/28, IE4 on Win98 lastIndexOf("boundary=") workaround
* @version 1.2, 99/12/20, IE4 on Mac readNextPart() workaround
* @version 1.1, 99/01/15, JSDK readLine() bug workaround
* @version 1.0, 98/09/18
*/
public class MultipartRequest {
private static final int DEFAULT_MAX_POST_SIZE = 1024 * 1024 * 10; // 1 Meg
private static final String NO_FILE = "unknown";
private HttpServletRequest req;
private File dir=null;
private int maxSize;
private String tempFilename; //add by lzl
private boolean defaultFileFlag=false; //add by lzl
private int fileNo=1; //add by lzl
private Hashtable fileFullPaths; // add by wguzgg
private Hashtable fileLengths; //add by wguzgg
private Hashtable fileLocalPaths; // add by wguzgg
private Hashtable parameters = new Hashtable(); // name - Vector of values
private Hashtable files = new Hashtable(); // name - UploadedFile
//add by wguzgg
public long getFileLengths(String fn) {
Long fl=(Long)fileLengths.get(fn);
return fl.longValue();
}
//add by wguzgg
public String getFileFullPath(String fn) {
String fp=(String)fileFullPaths.get(fn);
return fp;
}
//add by wguzgg
public String getFileLocalPath(String fn) {
String flp=(String)fileLocalPaths.get(fn);
return flp;
}
//add by lzl
public MultipartRequest(HttpServletRequest request,String saveDirectory,boolean fileFlag) throws IOException {
this(request, saveDirectory, DEFAULT_MAX_POST_SIZE,fileFlag);
}
/**
* Constructs a new MultipartRequest to handle the specified request,
* saving any uploaded files to the given directory, and limiting the
* upload size to 1 Megabyte. If the content is too large, an
* IOException is thrown. This constructor actually parses the
* multipart/form-data and throws an IOException if there's any
* problem reading or parsing the request.
*
* @param request the servlet request
* @param saveDirectory the directory in which to save any uploaded files
* @exception IOException if the uploaded content is larger than 1 Megabyte
* or there's a problem reading or parsing the request
*/
public MultipartRequest(HttpServletRequest request,
String saveDirectory) throws IOException {
this(request, saveDirectory, DEFAULT_MAX_POST_SIZE);
}
/**
* Constructs a new MultipartRequest to handle the specified request,
* saving any uploaded files to the given directory, and limiting the
* upload size to the specified length. If the content is too large, an
* IOException is thrown. This constructor actually parses the
* multipart/form-data and throws an IOException if there's any
* problem reading or parsing the request.
*
* @param request the servlet request
* @param saveDirectory the directory in which to save any uploaded files
* @param maxPostSize the maximum size of the POST content
* @exception IOException if the uploaded content is larger than
* maxPostSize or there's a problem reading or parsing the request
*/
public MultipartRequest(HttpServletRequest request,
String saveDirectory,
int maxPostSize) throws IOException {
// Sanity check values
if (request == null)
throw new IllegalArgumentException("request cannot be null");
if (saveDirectory == null)
throw new IllegalArgumentException("saveDirectory cannot be null");
if (maxPostSize type2.length() ? type1 : type2);
}
if (type == null ||
!type.toLowerCase().startsWith("multipart/form-data")) {
throw new IOException("Posted content type isn't multipart/form-data");
}
// Get the boundary string; it's included in the content type.
// Should look something like "------------------------12012133613061"
String boundary = extractBoundary(type);
if (boundary == null) {
throw new IOException("Separation boundary was not specified");
}
// Construct the special input stream we'll read from
MultipartInputStreamHandler in =
new MultipartInputStreamHandler(req.getInputStream(), length);
// Read the first line, should be the first boundary
String line = in.readLine();
if (line == null) {
throw new IOException("Corrupt form data: premature ending");
}
// Verify that the line is the boundary
if (!line.startsWith(boundary)) {
throw new IOException("Corrupt form data: no leading boundary");
}
// Now that we're just beyond the first boundary, loop over each part
boolean done = false;
while (!done) {
done = readNextPart(in, boundary);
}
}
/**
* A utility method that reads an individual part. Dispatches to
* readParameter() and readAndSaveFile() to do the actual work. A
* subclass can override this method for a better optimized or
* differently behaved implementation.
*
* @param in the stream from which to read the part
* @param boundary the boundary separating parts
* @return a flag indicating whether this is the last part
* @exception IOException if there's a problem reading or parsing the
* request
*
* @see readParameter
* @see readAndSaveFile
*/
protected boolean readNextPart(MultipartInputStreamHandler in,
String boundary) throws IOException {
// Read the first line, should look like this:
// content-disposition: form-data; name="field1"; filename="file1.txt"
String line = in.readLine();
if (line == null) {
// No parts left, we're done
return true;
}
else if (line.length() == 0) {
// IE4 on Mac sends an empty line at the end; treat that as the end.
// Thanks to Daniel Lemire and Henri Tourigny for this fix.
return true;
}
// Parse the content-disposition line
String[] dispInfo = extractDispositionInfo(line);
String disposition = dispInfo[0];
String name = dispInfo[1];
String filename = dispInfo[2];
// Now onto the next line. This will either be empty
// or contain a Content-Type and then an empty line.
line = in.readLine();
if (line == null) {
// No parts left, we're done
return true;
}
// Get the content type, or null if none specified
String contentType = extractContentType(line);
if (contentType != null) {
// Eat the empty line
line = in.readLine();
if (line == null || line.length() > 0) { // line should be empty
throw new
IOException("Malformed line after content type: " + line);
}
}
else {
// Assume a default content type
contentType = "application/octet-stream";
}
// Now, finally, we read the content (end after reading the boundary)
if (filename == null) {
// This is a parameter, add it to the vector of values
String value = readParameter(in, boundary);
if (value.equals("")) {
value = null; // treat empty strings like nulls
}
Vector existingValues = (Vector)parameters.get(name);
if (existingValues == null) {
existingValues = new Vector();
parameters.put(name, existingValues);
}
existingValues.addElement(value);
}
else {
// This is a file
readAndSaveFile(in, boundary, filename, contentType,name);
if (fileLocalPaths==null) //add by wguzgg
fileLocalPaths=new Hashtable(); //add by wguzgg
fileLocalPaths.put(new String(filename),dir.getAbsolutePath()); //add by wguzgg
if (fileLengths==null) //add by wguzgg
fileLengths=new Hashtable(); //add by wguzgg
File f = new File(dir + File.separator + filename); //add by wguzgg
Long fileLength=new Long(f.length()); //add by wguzgg
fileLengths.put(new String(filename),fileLength); //add by wguzgg
if (filename.equals(NO_FILE)) {
files.put(name, new UploadedFile(null, null, null));
}
else {
if(fileNo==1 && !defaultFileFlag){
String fileType=filename.substring(filename.indexOf("."));
filename=""+tempFilename+fileType.trim();
}
files.put(name,new UploadedFile(dir.toString(), filename, contentType));
fileNo++;
}
}
return false; // there's more to read
}
/**
* A utility method that reads a single part of the multipart request
* that represents a parameter. A subclass can override this method
* for a better optimized or differently behaved implementation.
*
* @param in the stream from which to read the parameter information
* @param boundary the boundary signifying the end of this part
* @return the parameter value
* @exception IOException if there's a problem reading or parsing the
* request
*/
protected String readParameter(MultipartInputStreamHandler in,
String boundary) throws IOException {
StringBuffer sbuf = new StringBuffer();
String line;
while ((line = in.readLine()) != null) {
if (line.startsWith(boundary)) break;
sbuf.append(line + "rn"); // add the rn in case there are many lines
}
if (sbuf.length() == 0) {
return null; // nothing read
}
sbuf.setLength(sbuf.length() - 2); // cut off the last line's rn
return sbuf.toString(); // no URL decoding needed
}
/**
* A utility method that reads a single part of the multipart request
* that represents a file, and saves the file to the given directory.
* A subclass can override this method for a better optimized or
* differently behaved implementation.
*
* @param in the stream from which to read the file
* @param boundary the boundary signifying the end of this part
* @param dir the directory in which to save the uploaded file
* @param filename the name under which to save the uploaded file
* @exception IOException if there's a problem reading or parsing the
* request
*/
protected void readAndSaveFile(MultipartInputStreamHandler in,
String boundary,
String filename,
String contentType,
String name) throws IOException {
OutputStream out = null;
// A filename of NO_FILE means no file was sent, so just read to the
// next boundary and ignore the empty contents
if (filename.equals(NO_FILE)) {
out = new ByteArrayOutputStream(); // write to nowhere
}
// A MacBinary file goes through a decoder
else if (contentType.equals("application/x-macbinary")){
File f = new File(dir + File.separator + filename);
out = new MacBinaryDecoderOutputStream(
new BufferedOutputStream(
new FileOutputStream(f), 8 * 1024));
}
// A real file's contents are written to disk
else {
if(fileNo==1 && !defaultFileFlag){
String fileType=filename.substring(filename.indexOf("."));
filename=""+tempFilename+fileType.trim();
}
File f = new File(dir + File.separator + filename);
out = new BufferedOutputStream(new FileOutputStream(f), 8 * 1024);
}
byte[] bbuf = new byte[100 * 1024]; // 100K
int result;
String line;
// ServletInputStream.readLine() has the annoying habit of
// adding a rn to the end of the last line.
// Since we want a byte-for-byte transfer, we have to cut those chars.
boolean rnflag = false;
while ((result = in.readLine(bbuf, 0, bbuf.length)) != -1) {
// Check for boundary
if (result > 2 && bbuf[0] == '-' && bbuf[1] == '-') { // quick pre-check
line = new String(bbuf, 0, result); //has edited by lzl
if (line.startsWith(boundary)) break;
}
// Are we supposed to write rn for the last iteration?
if (rnflag) {
out.write('r'); out.write('n');
rnflag = false;
}
// Write the buffer, postpone any ending rn
if (result >= 2 &&
bbuf[result - 2] == 'r' &&
bbuf[result - 1] == 'n') {
out.write(bbuf, 0, result - 2); // skip the last 2 chars
rnflag = true; // make a note to write them on the next iteration
}
else {
out.write(bbuf, 0, result);
}
}
out.flush();
out.close();
}
// Extracts and returns the boundary token from a line.
//
private String extractBoundary(String line) {
// Use lastIndexOf() because IE 4.01 on Win98 has been known to send the
// "boundary=" string multiple times. Thanks to David Wall for this fix.
int index = line.lastIndexOf("boundary=");
if (index == -1) {
return null;
}
String boundary = line.substring(index + 9); // 9 for "boundary="
// The real boundary is always preceeded by an extra "--"
boundary = "--" + boundary;
return boundary;
}
// Extracts and returns disposition info from a line, as a String array
// with elements: disposition, name, filename. Throws an IOException
// if the line is malformatted.
//
private String[] extractDispositionInfo(String line) throws IOException {
// Return the line's data as an array: disposition, name, filename
String[] retval = new String[3];
// Convert the line to a lowercase string without the ending rn
// Keep the original line for error messages and for variable names.
String origline = line;
line = origline.toLowerCase();
// Get the content disposition, should be "form-data"
int start = line.indexOf("content-disposition: ");
int end = line.indexOf(";");
if (start == -1 || end == -1) {
throw new IOException("Content disposition corrupt: " + origline);
}
String disposition = line.substring(start + 21, end);
if (!disposition.equals("form-data")) {
throw new IOException("Invalid content disposition: " + disposition);
}
// Get the field name
start = line.indexOf("name="", end); // start at last semicolon
end = line.indexOf(""", start + 7); // skip name="
if (start == -1 || end == -1) {
throw new IOException("Content disposition corrupt: " + origline);
}
String name = origline.substring(start + 6, end);
// Get the filename, if given
String filename = null;
start = line.indexOf("filename="", end + 2); // start after name
end = line.indexOf(""", start + 10); // skip filename="
if (start != -1 && end != -1) { // note the !=
filename = origline.substring(start + 10, end);
String temp=new String(filename); //add by wguzgg
// The filename may contain a full path. Cut to just the filename.
int slash =
Math.max(filename.lastIndexOf('/'), filename.lastIndexOf('\'));
if (slash > -1) {
filename = filename.substring(slash + 1); // past last slash
}
if (filename.equals("")) filename = NO_FILE; // sanity check
if (fileFullPaths==null) //add by wguzgg
fileFullPaths=new Hashtable(); //add by wguzgg
fileFullPaths.put(new String(filename),temp); //add by wguzgg
}
// Return a String array: disposition, name, filename
retval[0] = disposition;
retval[1] = name;
retval[2] = filename;
return retval;
}
// Extracts and returns the content type from a line, or null if the
// line was empty. Throws an IOException if the line is malformatted.
//
private String extractContentType(String line) throws IOException {
String contentType = null;
// Convert the line to a lowercase string
String origline = line;
line = origline.toLowerCase();
// Get the content type, if any
if (line.startsWith("content-type")) {
int start = line.indexOf(" ");
if (start == -1) {
throw new IOException("Content type corrupt: " + origline);
}
contentType = line.substring(start + 1);
}
else if (line.length() != 0) { // no content type, so should be empty
throw new IOException("Malformed line after disposition: " + origline);
}
return contentType;
}
}
// A class to hold information about an uploaded file.
//
class UploadedFile {
private String dir;
private String filename;
private String type;
UploadedFile(String dir, String filename, String type) {
this.dir = dir;
this.filename = filename;
this.type = type;
}
public String getContentType() {
return type;
}
public String getFilesystemName() {
return filename;
}
public File getFile() {
if (dir == null || filename == null) {
return null;
}
else {
return new File(dir + File.separator + filename);
}
}
}
// A class to aid in reading multipart/form-data from a ServletInputStream.
// It keeps track of how many bytes have been read and detects when the
// Content-Length limit has been reached. This is necessary since some
// servlet engines are slow to notice the end of stream.
//
// Mac users: The Mac doesn't like class names which exceed 32 characters
// (including the ".class") so while this class is usable from a JAR
// anywhere, it won't compile on a Mac.
//
class MultipartInputStreamHandler {
ServletInputStream in;
int totalExpected;
int totalRead = 0;
byte[] buf = new byte[8 * 1024];
public MultipartInputStreamHandler(ServletInputStream in,
int totalExpected) {
this.in = in;
this.totalExpected = totalExpected;
}
// Reads the next line of input. Returns null to indicate the end
// of stream.
//
public String readLine() throws IOException {
StringBuffer sbuf = new StringBuffer();
int result;
String line;
do {
result = this.readLine(buf, 0, buf.length); // this.readLine() does +=
if (result != -1) {
sbuf.append(new String(buf, 0, result)); //has edited by lzl
}
} while (result == buf.length); // loop only if the buffer was filled
if (sbuf.length() == 0) {
return null; // nothing read, must be at the end of stream
}
sbuf.setLength(sbuf.length() - 2); // cut off the trailing rn
return sbuf.toString();
}
// A pass-through to ServletInputStream.readLine() that keeps track
// of how many bytes have been read and stops reading when the
// Content-Length limit has been reached.
//
public int readLine(byte b[], int off, int len) throws IOException {
if (totalRead >= totalExpected) {
return -1;
}
else {
if (len > (totalExpected - totalRead)) {
len = totalExpected - totalRead; // keep from reading off end
}
int result = in.readLine(b, off, len);
if (result > 0) {
totalRead += result;
}
return result;
}
}
}
// Class to filters MacBinary files to normal files on the fly
// Optimized for speed more than readability
class MacBinaryDecoderOutputStream extends FilterOutputStream {
int bytesFiltered = 0;
int dataForkLength = 0;
public MacBinaryDecoderOutputStream(OutputStream out) {
super(out);
}
public void write(int b) throws IOException {
// Bytes 83 through 86 are a long representing the data fork length
// Check
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