WEB源码(ASP,PHP,...)

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Java

MultipartStream.java：源码内容
							
package com.gamvan.fileUpload;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import com.gamvan.tools.TypeChange;
public class MultipartStream{
    /**
     * 取当前读取进度
     */
    private long readsBytes = 0;
    
    /**
     * The maximum length of <code>header-part</code> that will be
     * processed (10 kilobytes = 10240 bytes.).
     */
    public static final int HEADER_PART_SIZE_MAX = 10240;
    
    /**
     * The default length of the buffer used for processing a request.
     */
    protected static final int DEFAULT_BUFSIZE = 4096;
    /**
     * A byte sequence that marks the end of <code>header-part</code>
     * (<code>CRLFCRLF</code>).
     */
    protected static final byte[] HEADER_SEPARATOR = {0x0D, 0x0A, 0x0D, 0x0A};
    /**
     * A byte sequence that that follows a delimiter that will be
     * followed by an encapsulation (<code>CRLF</code>).
     */
    protected static final byte[] FIELD_SEPARATOR = { 0x0D, 0x0A };
    /**
     * A byte sequence that that follows a delimiter of the last
     * encapsulation in the stream (<code>--</code>).
     */
    protected static final byte[] STREAM_TERMINATOR = { 0x2D, 0x2D };
    /**
     * The input stream from which data is read.
     */
    private InputStream input;
    /**
     * The length of the boundary token plus the leading <code>CRLF--</code>.
     */
    private int boundaryLength;
    /**
     * The amount of data, in bytes, that must be kept in the buffer in order
     * to detect delimiters reliably.
     */
    private int keepRegion;
    /**
     * The byte sequence that partitions the stream.
     */
    private byte[] boundary;
    /**
     * The length of the buffer used for processing the request.
     */
    private int bufSize;
    /**
     * The buffer used for processing the request.
     */
    private byte[] buffer;
    /**
     * The index of first valid character in the buffer.
     * <br>
     * 0 <= head < bufSize
     */
    private int head;
    /**
     * The index of last valid characer in the buffer + 1.
     * <br>
     * 0 <= tail <= bufSize
     */
    private int tail;
    /**
     * The content encoding to use when reading headers.
     */
    private String headerEncoding;
    /**
     * Default constructor.
     *
     * @see #MultipartStream(InputStream, byte[], int)
     * @see #MultipartStream(InputStream, byte[])
     *
     */
    public MultipartStream()
    {
    }
    public MultipartStream(InputStream input, byte[] boundary,int bufSize){
        this.input = input;
        this.bufSize = bufSize;
        this.buffer = new byte[bufSize];
        // We prepend CR/LF to the boundary to chop trailng CR/LF from
        // body-data tokens.
        this.boundary = new byte[boundary.length + 4];
        this.boundaryLength = boundary.length + 4;
        this.keepRegion = boundary.length + 3;
        this.boundary[0] = 0x0D;
        this.boundary[1] = 0x0A;
        this.boundary[2] = 0x2D;
        this.boundary[3] = 0x2D;
        System.arraycopy(boundary, 0, this.boundary, 4, boundary.length);
        head = 0;
        tail = 0;
    }
    public MultipartStream(InputStream input, byte[] boundary) throws IOException{
        this(input, boundary, DEFAULT_BUFSIZE);
    }
    
    public String getHeaderEncoding(){
        return headerEncoding;
    }
    
    public void setHeaderEncoding(String encoding){
        headerEncoding = encoding;
    }
    
    public byte readByte() throws IOException{
        // Buffer depleted ?
        if (head == tail){
            head = 0;
            // Refill.
            tail = input.read(buffer, head, bufSize);
            if (tail == -1){
                // No more data available.
                throw new IOException("No more data is available");
            }
        }
        return buffer[head++];
    }
    
    /**
     * 
     * @return
     * @throws MalformedStreamException
     */
    public boolean readBoundary() throws MalformedStreamException{
        byte[] marker = new byte[2];
        boolean nextChunk = false;
        head += boundaryLength;
        try{
            marker[0] = readByte();
            marker[1] = readByte();
            if (arrayequals(marker, STREAM_TERMINATOR, 2)){
                nextChunk = false;
            }else if (arrayequals(marker, FIELD_SEPARATOR, 2)){
                nextChunk = true;
            }else{
                throw new MalformedStreamException(
                        "Unexpected characters follow a boundary");
            }
        }
        catch (IOException e)
        {
            throw new MalformedStreamException("Stream ended unexpectedly");
        }
        return nextChunk;
    }
    
    
    
    public void setBoundary(byte[] boundary) //设置边界
        throws IllegalBoundaryException
    {
        if (boundary.length != boundaryLength - 4){
            throw new IllegalBoundaryException("The length of a boundary token can not be changed");
        }
        System.arraycopy(boundary, 0, this.boundary, 4, boundary.length);
    }
    
/*
 * 
 * 
 * 
 */    
    public String readHeaders() throws MalformedStreamException{
        int i = 0;
        byte b[] = new byte[1];
        // to support multi-byte characters
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int sizeMax = HEADER_PART_SIZE_MAX;
        int size = 0;
        while (i < 4){
            try{
                b[0] = readByte();
            }catch (IOException e){
                throw new MalformedStreamException("Stream ended unexpectedly");
            }
            size++; //当前读取字节数
            readsBytes += size; //读取进度 
            
            if (b[0] == HEADER_SEPARATOR[i]){
                i++;
            }else{
                i = 0;
            }
            if (size <= sizeMax){
                baos.write(b[0]);
            }
        }
        String headers = null;
        if (headerEncoding != null){
            try{
                headers = baos.toString(headerEncoding);
                
            }catch (UnsupportedEncodingException e){
                // Fall back to platform default if specified encoding is not
                // supported.
                headers = baos.toString();
            }
        }else{
            headers = baos.toString();
        }
        return headers;
    }
    
    public int readBodyData(OutputStream output,HttpServletRequest req) throws MalformedStreamException, IOException{
        boolean done = false;
        int pad;
        int pos;
        int bytesRead;
        int total = 0;
        
        HttpSession session = req.getSession();
        
        while (!done)
        {
            // Is boundary token present somewere in the buffer?
            pos = findSeparator();
            if (pos != -1)
            {
                // Write the rest of the data before the boundary.
                output.write(buffer, head, pos - head);
                total += pos - head;
                head = pos;
                done = true;
            }
            else
            {
                // Determine how much data should be kept in the
                // buffer.
                if (tail - head > keepRegion)
                {
                    pad = keepRegion;
                }
                else
                {
                    pad = tail - head;
                }
                // Write out the data belonging to the body-data.
                output.write(buffer, head, tail - head - pad);
                // Move the data to the beging of the buffer.
                
                total += tail - head - pad;
                System.arraycopy(buffer, tail - pad, buffer, 0, pad);
                
               //if(readsBytes==0)
                //readsBytes = total; //当前读取的字节数。
                
                // Refill buffer with new data.
                head = 0;
                bytesRead = input.read(buffer, pad, bufSize - pad);
                if (bytesRead != -1)
                {
                    tail = pad + bytesRead;
                }
                else
                {
                    // The last pad amount is left in the buffer.
                    // Boundary can't be in there so write out the
                    // data you have and signal an error condition.
                    output.write(buffer, 0, pad);
                    output.flush();
                    total += pad;
                    throw new MalformedStreamException(
                            "Stream ended unexpectedly");
                }
            }
            /************************************
             * 读取进度
             ************************************/
            session.setAttribute("readsBytes", TypeChange.longToString(total));
            /***************************************/ 
        }
        output.flush();
        readsBytes = total;
        return total;
    }
    
    /**
     * 
     * @return
     * @throws MalformedStreamException
     * @throws IOException
     */
    public int discardBodyData() throws MalformedStreamException,IOException{
        boolean done = false;
        int pad;
        int pos;
        int bytesRead;
        int total = 0;
        while (!done){
            // Is boundary token present somewere in the buffer?
            pos = findSeparator();
            if (pos != -1){
                // Write the rest of the data before the boundary.
                total += pos - head;
                head = pos;
                done = true;
            }else{
                // Determine how much data should be kept in the
                // buffer.
                if (tail - head > keepRegion)
                {
                    pad = keepRegion;
                }
                else
                {
                    pad = tail - head;
                }
                total += tail - head - pad;
                // Move the data to the beging of the buffer.
                System.arraycopy(buffer, tail - pad, buffer, 0, pad);
                // Refill buffer with new data.
                head = 0;
                bytesRead = input.read(buffer, pad, bufSize - pad);
             
                if (bytesRead != -1)
                {
                    tail = pad + bytesRead;
                }
                else
                {
                    // The last pad amount is left in the buffer.
                    // Boundary can't be in there so signal an error
                    // condition.
                    total += pad;
                    throw new MalformedStreamException(
                            "Stream ended unexpectedly");
                }
            }
        }
        readsBytes = total;
        return total;
    }
    
    
    /**
     * 
     * @return
     * @throws IOException
     */
    public boolean skipPreamble() throws IOException{
        // First delimiter may be not preceeded with a CRLF.
        System.arraycopy(boundary, 2, boundary, 0, boundary.length - 2);
        boundaryLength = boundary.length - 2;
        try{
            // Discard all data up to the delimiter. 分隔符
            discardBodyData();
            // Read boundary - if succeded, the stream contains an
            // encapsulation.
            return readBoundary();
        }catch (MalformedStreamException e){
            return false;
        }
        finally{
            // Restore delimiter.
            System.arraycopy(boundary, 0, boundary, 2, boundary.length - 2);
            boundaryLength = boundary.length;
            boundary[0] = 0x0D;
            boundary[1] = 0x0A;
        }
    }
    
    
    public static boolean arrayequals(byte[] a, byte[] b, int count){
        for (int i = 0; i < count; i++)
        {
            if (a[i] != b[i])
            {
                return false;
            }
        }
        return true;
    }
    
    
    
    protected int findByte(byte value,int pos){
        for (int i = pos; i < tail; i++)
        {
            if (buffer[i] == value)
            {
                return i;
            }
        }
        return -1;
    }
    
    
    
    protected int findSeparator() {
        int first;
        int match = 0;
        int maxpos = tail - boundaryLength;
        for (first = head;
             (first <= maxpos) && (match != boundaryLength);
             first++)
        {
            first = findByte(boundary[0], first);
            if (first == -1 || (first > maxpos))
            {
                return -1;
            }
            for (match = 1; match < boundaryLength; match++)
            {
                if (buffer[first + match] != boundary[match])
                {
                    break;
                }
            }
        }
        if (match == boundaryLength)
        {
            return first - 1;
        }
        return -1;
    }
    
    
    public String toString(){
        StringBuffer sbTemp = new StringBuffer();
        sbTemp.append("boundary='");
        sbTemp.append(String.valueOf(boundary));
        sbTemp.append("'nbufSize=");
        sbTemp.append(bufSize);
        return sbTemp.toString();
    }
    
    
    public class MalformedStreamException extends IOException {
        /**
         * Constructs a <code>MalformedStreamException</code> with no
         * detail message.
         */
        public MalformedStreamException()
        {
            super();
        }
        /**
         * Constructs an <code>MalformedStreamException</code> with
         * the specified detail message.
         *
         * @param message The detail message.
         */
        public MalformedStreamException(String message)
        {
            super(message);
        }
    }
   
    public class IllegalBoundaryException extends IOException {
        /**
         * Constructs an <code>IllegalBoundaryException</code> with no
         * detail message.
         */
        public IllegalBoundaryException()
        {
            super();
        }
        /**
         * Constructs an <code>IllegalBoundaryException</code> with
         * the specified detail message.
         *
         * @param message The detail message.
         */
        public IllegalBoundaryException(String message)
        {
            super(message);
        }
    }
    /**
     * 读取进度
     */
    public long getReadsBytes(){
        return this.readsBytes;
    }
    
    // ------------------------------------------------------ Debugging methods
    // These are the methods that were used to debug this stuff.
    /*
    // Dump data.
    protected void dump()
    {
        System.out.println("01234567890");
        byte[] temp = new byte[buffer.length];
        for(int i=0; i<buffer.length; i++)
        {
            if (buffer[i] == 0x0D || buffer[i] == 0x0A)
            {
                temp[i] = 0x21;
            }
            else
            {
                temp[i] = buffer[i];
            }
        }
        System.out.println(new String(temp));
        int i;
        for (i=0; i<head; i++)
            System.out.print(" ");
        System.out.println("h");
        for (i=0; i<tail; i++)
            System.out.print(" ");
        System.out.println("t");
        System.out.flush();
    }
    // Main routine, for testing purposes only.
    //
    // @param args A String[] with the command line arguments.
    // @exception Exception, a generic exception.
    public static void main( String[] args )
        throws Exception
    {
        File boundaryFile = new File("boundary.dat");
        int boundarySize = (int)boundaryFile.length();
        byte[] boundary = new byte[boundarySize];
        FileInputStream input = new FileInputStream(boundaryFile);
        input.read(boundary,0,boundarySize);
        input = new FileInputStream("multipart.dat");
        MultipartStream chunks = new MultipartStream(input, boundary);
        int i = 0;
        String header;
        OutputStream output;
        boolean nextChunk = chunks.skipPreamble();
        while (nextChunk)
        {
            header = chunks.readHeaders();
            System.out.println("!"+header+"!");
            System.out.println("wrote part"+i+".dat");
            output = new FileOutputStream("part"+(i++)+".dat");
            chunks.readBodyData(output);
            nextChunk = chunks.readBoundary();
        }
    }
    */
}

						