怎样用JavaServlet或JavaBean作上传文件的处理,详细些或有什么资料??我的分只给一个人哦。

CDSoftwareWj 2001-08-28 03:15:41
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CDSoftwareWj 2001-08-29
老大不能用呀,光是语法错就是一堆,改了也不行,哎,我还是自己写一个吧,谢谢你的热情 hehe^^ 下次见。
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haibei 2001-08-28
我看到的一些资料
用jspsmartupload bean组件,在www.jspsmart.com或http://lapse.ibbi.net/
下载
一个开放源码的上传文件
ycshowtop(Bug制造机)

/*

* A utility class to handle <tt>multipart/form-data</tt> 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 co
ntent)
* or internationalized content (such as non Latin-1 filenames).
* <p>
* It's used like this:
* <blockquote><pre>

*指定上传文件最大字节
* MultipartRequest multi = new MultipartRequest(req, ".", 2*1024);
或使用默认2M,
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();
* }
* }
* </pre></blockquote>
*
* A client can upload files using an HTML form with the following str
ucture.
* Note that not all browsers support file uploads.
* <blockquote><pre>
* <FORM ACTION="/servlet/Handler" 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>
* </pre></blockquote>
* <p>

*/

import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class MultipartRequest {

private static final int DEFAULT_MAX_POST_SIZE = 1024 * 1024; // 1Meg
private static final String NO_FILE = "unknown";

private HttpServletRequest req;
private File dir;
private int maxSize;

private Hashtable parameters = new Hashtable(); // name - Vector of values
private Hashtable files = new Hashtable(); // name - UploadedFile

/**
* 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
* <tt>multipart/form-data</tt> 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
* <tt>multipart/form-data</tt> 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
* <tt>maxPostSize</tt> 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 <= 0)
{
throw new IllegalArgumentException("maxPostSize must be positive");
}

// Save the request, dir, and max size
req = request;
dir = new File(saveDirectory);
maxSize = maxPostSize;

// Check saveDirectory is truly a directory
if (!dir.isDirectory())
throw new IllegalArgumentException("Not a directory: " + saveDirectory);

// Check saveDirectory is writable
if (!dir.canWrite())
throw new IllegalArgumentException("Not writable: " + saveDirectory);

// Now parse the request saving data to "parameters" and "files";

// write the file contents to the saveDirectory
readRequest();
}

/**
* Constructor with an old signature, kept for backward compatibility.
* Without this constructor, a servlet compiled against a previous version
* of this class (pre 1.4) would have to be recompiled to link with this
* version. This constructor supports the linking via the old signature.
* Callers must simply be careful to pass in an HttpServletRequest.
*
*/
public MultipartRequest(ServletRequest request,String saveDirectory)
throws IOException
{
this((HttpServletRequest)request, saveDirectory);
}

/**
* Constructor with an old signature, kept for backward compatibility.
* Without this constructor, a servlet compiled against a previous version
* of this class (pre 1.4) would have to be recompiled to link with this
* version. This constructor supports the linking via the old signature.
* Callers must simply be careful to pass in an HttpServletRequest.
*
*/
public MultipartRequest(ServletRequest request,String saveDirectory,int maxPostSize)
throws IOException
{
this((HttpServletRequest)request, saveDirectory, maxPostSize);
}

/**
* Returns the names of all the parameters as an Enumeration of
* Strings. It returns an empty Enumeration if there are no parameters.
*
* @return the names of all the parameters as an Enumeration of Strings
*/

public Enumeration getParameterNames()
{
return parameters.keys();
}

/**
* Returns the names of all the uploaded files as an Enumeration of
* Strings. It returns an empty Enumeration if there are no uploaded
* files. Each file name is the name specified by the form, not by
* the user.
*
* @return the names of all the uploaded files as an Enumeration of Strings
*/

public Enumeration getFileNames()
{
return files.keys();
}

/**
* Returns the value of the named parameter as a String, or null if
* the parameter was not sent or was sent without a value. The value
* is guaranteed to be in its normal, decoded form. If the parameter
* has multiple values, only the last one is returned (for backward
* compatibility). For parameters with multiple values, it's possible
* the last "value" may be null.
*
* @param name the parameter name
* @return the parameter value
*/

public String getParameter(String name)
{
try {
Vector values = (Vector)parameters.get(name);
if (values == null ¦¦ values.size() == 0)
{
return null;
}
String value = (String)values.elementAt(values.size() - 1);
return value;
}
catch (Exception e)
{
return null;
}
}

/**
* Returns the values of the named parameter as a String array, or null if
* the parameter was not sent. The array has one entry for each parameter
* field sent. If any field was sent without a value that entry is stored
* in the array as a null. The values are guaranteed to be in their
* normal, decoded form. A single value is returned as a one-element array.
*
* @param name the parameter name
* @return the parameter values
*/

public String[] getParameterValues(String name)
{
try {
Vector values = (Vector)parameters.get(name);
if (values == null ¦¦ values.size() == 0) {
return null;
}
String[] valuesArray = new String[values.size()];
values.copyInto(valuesArray);
return valuesArray;
}
catch (Exception e) {
return null;
}
}

/**
* Returns the filesystem name of the specified file, or null if the
* file was not included in the upload. A filesystem name is the name
* specified by the user. It is also the name under which the file is
* actually saved.
*
* @param name the file name
* @return the filesystem name of the file
*/

public String getFilesystemName(String name) {
try {
UploadedFile file = (UploadedFile)files.get(name);
return file.getFilesystemName(); // may be null
}
catch (Exception e) {
return null;
}
}

/**
* Returns the content type of the specified file (as supplied by the
* client browser), or null if the file was not included in the upload.
*
* @param name the file name
* @return the content type of the file
*/
public String getContentType(String name) {
try {
UploadedFile file = (UploadedFile)files.get(name);
return file.getContentType(); // may be null
}
catch (Exception e) {
return null;
}
}

/**
* Returns a File object for the specified file saved on the server's
* filesystem, or null if the file was not included in the upload.
*
* @param name the file name
* @return a File object for the named file
*/

public File getFile(String name) {
try {
UploadedFile file = (UploadedFile)files.get(name);
return file.getFile(); // may be null
}
catch (Exception e) {
return null;
}
}

/**
* The workhorse method that actually parses the request. A subclass
* can override this method for a better optimized or differently
* behaved implementation.
*
* @exception IOException if the uploaded content is larger than
* <tt>maxSize</tt> or there's a problem parsing the request
*/
protected void readRequest() throws IOException {
// Check the content length to prevent denial of service attacks
int length = req.getContentLength();
if (length > maxSize) {
throw new IOException("Posted content length of " + length + " exceeds limit of " + maxSize);
}

// Check the content type to make sure it's "multipart/form-data"

// Access header two ways to work around WebSphere oddities
String type = null;
String type1 = req.getHeader("Content-Type");
String type2 = req.getContentType();
// If one value is null, choose the other value
if (type1 == null && type2 != null) {
type = type2;
}
else if (type2 == null && type1 != null) {
type = type1;
}
// If neither value is null, choose the longer value
else if (type1 != null && type2 != null) {
type = (type1.length() > 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);
if (filename.equals(NO_FILE)) {
files.put(name, new UploadedFile(null, null, null));
}
else {
files.put(name,
new UploadedFile(dir.toString(), filename, contentType));
}
}
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 + "\r\n"); // add the \r\n 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 \r\n
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) 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 {
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 \r\n 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, "ISO-8859-1");
if (line.startsWith(boundary)) break;
}
// Are we supposed to write \r\n for the last iteration?
if (rnflag) {
out.write('\r'); out.write('\n');
rnflag = false;
}
// Write the buffer, postpone any ending \r\n
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 \r\n

// 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);
// 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
}

// 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, "ISO-8859-1"));
}
} 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 \r\n
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 <= 86 first to short circuit early in the common case
if (bytesFiltered <= 86 && bytesFiltered >= 83) {
int leftShift = (86 - bytesFiltered) * 8;
dataForkLength = dataForkLength ¦ (b & 0xff) << leftShift;
}
// Bytes 128 up to (128 + dataForkLength - 1) are the data fork
else if (bytesFiltered < (128 + dataForkLength) && bytesFiltered >= 128) {
out.write(b);
}
bytesFiltered++;
}

public void write(byte b[]) throws IOException {
write(b, 0, b.length);
}

public void write(byte b[], int off, int len) throws IOException {
// If the write is for content past the end of the data fork, ignore
if (bytesFiltered >= (128 + dataForkLength)) {
bytesFiltered += len;
}
// If the write is entirely within the data fork, write it directly
else if (bytesFiltered >= 128 &&
(bytesFiltered + len) <= (128 + dataForkLength)) {
out.write(b, off, len);
bytesFiltered += len;
}
// Otherwise, do the write a byte at a time to get the logic above
else {
for (int i = 0 ; i < len ; i++) {
write(b[off + i]);
}
}
}
}

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