bodycontentimpl.java

这是一个法律事务所系统源码

/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:  
 *       "This product includes software developed by the 
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written 
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 */ 

package org.apache.jasper.runtime;

import java.io.IOException;
import java.io.Writer;
import java.io.Reader;
import java.io.CharArrayReader;
import java.io.PrintWriter;

import javax.servlet.ServletResponse;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyContent;

import org.apache.jasper.Constants;

/**
 * Write text to a character-output stream, buffering characters so as
 * to provide for the efficient writing of single characters, arrays,
 * and strings. 
 *
 * Provide support for discarding for the output that has been buffered. 
 *
 * @author Rajiv Mordani
 */
public class BodyContentImpl extends BodyContent {

    private char[] cb;
    protected int bufferSize = Constants.DEFAULT_BUFFER_SIZE;
    private int nextChar;
    static String lineSeparator = System.getProperty("line.separator");


    public BodyContentImpl (JspWriter writer) {
        super(writer);
	cb = new char[bufferSize];
	nextChar = 0;
    }

    /**
     * Write a single character.
     *
     */
    public void write(int c) throws IOException {
        synchronized (lock) {
            if (nextChar >= bufferSize) {
	        reAllocBuff (0);
	    }
            cb[nextChar++] = (char) c;
        }
    }

    private void reAllocBuff (int len) {
        //Need to re-allocate the buffer since it is to be
	//unbounded according to the updated spec..

        char[] tmp = new char [bufferSize];
	System.arraycopy(cb, 0, tmp, 0, cb.length);

	//XXX Should it be multiple of DEFAULT_BUFFER_SIZE??

	if (len <= Constants.DEFAULT_BUFFER_SIZE) {
	    cb = new char [bufferSize + Constants.DEFAULT_BUFFER_SIZE];
	    bufferSize += Constants.DEFAULT_BUFFER_SIZE;
	} else {
	    cb = new char [bufferSize + len];
	    bufferSize += len;
	}
	System.arraycopy(tmp, 0, cb, 0, tmp.length);
	tmp = null;
    }

    /**
     * Write a portion of an array of characters.
     *
     * <p> Ordinarily this method stores characters from the given array into
     * this stream's buffer, flushing the buffer to the underlying stream as
     * needed.  If the requested length is at least as large as the buffer,
     * however, then this method will flush the buffer and write the characters
     * directly to the underlying stream.  Thus redundant
     * <code>DiscardableBufferedWriter</code>s will not copy data unnecessarily.
     *
     * @param  cbuf  A character array
     * @param  off   Offset from which to start reading characters
     * @param  len   Number of characters to write
     *
     */
    public void write(char cbuf[], int off, int len) 
        throws IOException 
    {
        synchronized (lock) {

            if ((off < 0) || (off > cbuf.length) || (len < 0) ||
                ((off + len) > cbuf.length) || ((off + len) < 0)) {
                throw new IndexOutOfBoundsException();
            } else if (len == 0) {
                return;
            } 

            if (len >= bufferSize - nextChar)
		   reAllocBuff (len);

            System.arraycopy(cbuf, off, cb, nextChar, len);
	    nextChar+=len;
        }
    }

    /**
     * Write an array of characters.  This method cannot be inherited from the
     * Writer class because it must suppress I/O exceptions.
     */
    public void write(char buf[]) throws IOException {
	write(buf, 0, buf.length);
    }

    /**
     * Write a portion of a String.
     *
     * @param  s     String to be written
     * @param  off   Offset from which to start reading characters
     * @param  len   Number of characters to be written
     *
     */
    public void write(String s, int off, int len) throws IOException {
        synchronized (lock) {
	    if (len >= bufferSize - nextChar)
	        reAllocBuff(len);

            s.getChars(off, off + len, cb, nextChar);
	    nextChar += len;
        }
    }

    /**
     * Write a string.  This method cannot be inherited from the Writer class
     * because it must suppress I/O exceptions.
     */
    public void write(String s) throws IOException {
	write(s, 0, s.length());
    }


    /**
     * Write a line separator.  The line separator string is defined by the
     * system property <tt>line.separator</tt>, and is not necessarily a single
     * newline ('\n') character.
     *
     * @exception  IOException  If an I/O error occurs
     */

    public void newLine() throws IOException {
	synchronized (lock) {
	    write(lineSeparator);
	}
    }

    /**
     * Print a boolean value.  The string produced by <code>{@link
     * java.lang.String#valueOf(boolean)}</code> is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link
     * #write(int)}</code> method.
     *
     * @param      b   The <code>boolean</code> to be printed
     * @throws	   java.io.IOException
     */

    public void print(boolean b) throws IOException {
	write(b ? "true" : "false");
    }

    /**
     * Print a character.  The character is translated into one or more bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link
     * #write(int)}</code> method.
     *
     * @param      c   The <code>char</code> to be printed
     * @throws	   java.io.IOException
     */

    public void print(char c) throws IOException {
	write(String.valueOf(c));
    }

    /**
     * Print an integer.  The string produced by <code>{@link
     * java.lang.String#valueOf(int)}</code> is translated into bytes according
     * to the platform's default character encoding, and these bytes are
     * written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      i   The <code>int</code> to be printed
     * @see        java.lang.Integer#toString(int)
     * @throws	   java.io.IOException
     */

    public void print(int i) throws IOException {
	write(String.valueOf(i));
    }

    /**
     * Print a long integer.  The string produced by <code>{@link
     * java.lang.String#valueOf(long)}</code> is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      l   The <code>long</code> to be printed
     * @see        java.lang.Long#toString(long)
     * @throws	   java.io.IOException
     */

    public void print(long l) throws IOException {
	write(String.valueOf(l));
    }

    /**
     * Print a floating-point number.  The string produced by <code>{@link
     * java.lang.String#valueOf(float)}</code> is translated into bytes
     * according to the platform's default character encoding, and these bytes
     * are written in exactly the manner of the <code>{@link #write(int)}</code>
     * method.
     *
     * @param      f   The <code>float</code> to be printed
     * @see        java.lang.Float#toString(float)
     * @throws	   java.io.IOException
     */

    public void print(float f) throws IOException {
	write(String.valueOf(f));
    }

    /**
     * Print a double-precision floating-point number.  The string produced by
     * <code>{@link java.lang.String#valueOf(double)}</code> is translated into
     * bytes according to the platform's default character encoding, and these
     * bytes are written in exactly the manner of the <code>{@link
     * #write(int)}</code> method.
     *
     * @param      d   The <code>double</code> to be printed
     * @see        java.lang.Double#toString(double)