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Java Source | 1997-05-20 | 5.4 KB | 175 lines |
- /*
- * @(#)StringBufferInputStream.java 1.16 97/01/25
- *
- * Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
- *
- * This software is the confidential and proprietary information of Sun
- * Microsystems, Inc. ("Confidential Information"). You shall not
- * disclose such Confidential Information and shall use it only in
- * accordance with the terms of the license agreement you entered into
- * with Sun.
- *
- * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
- * SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
- * PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES
- * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
- * THIS SOFTWARE OR ITS DERIVATIVES.
- *
- * CopyrightVersion 1.1_beta
- *
- */
-
- package java.io;
-
- /**
- * This class allows an application to create an input stream in
- * which the bytes read are supplied by the contents of a string.
- * Applications can also read bytes from a byte array by using a
- * <code>ByteArrayInputStream</code>.
- * <p>
- * Only the low eight bits of each character in the string are used by
- * this class.
- *
- * @author Arthur van Hoff
- * @version 1.16, 01/25/97
- * @see java.io.ByteArrayInputStream
- * @see java.io.StringReader
- * @since JDK1.0
- * @deprecated This class does not properly convert characters into bytes. As
- * of JDK 1.1, the preferred way to create a stream from a
- * string is via the <code>StringReader</code> class.
- */
- public
- class StringBufferInputStream extends InputStream {
- /**
- * The string from which bytes are read.
- *
- * @since JDK1.0
- */
- protected String buffer;
-
- /**
- * The index of the next character to read from the input stream buffer.
- *
- * @see java.io.StringBufferInputStream#buffer
- * @since JDK1.0
- */
- protected int pos;
-
- /**
- * The number of valid characters in the input stream buffer.
- *
- * @see java.io.StringBufferInputStream#buffer
- * @since JDK1.0
- */
- protected int count;
-
- /**
- * Creates a string input stream to read data from the specified string.
- *
- * @param s the underlying input buffer.
- * @since JDK1.0
- */
- public StringBufferInputStream(String s) {
- this.buffer = s;
- count = s.length();
- }
-
- /**
- * Reads the next byte of data from this input stream. The value
- * byte is returned as an <code>int</code> in the range
- * <code>0</code> to <code>255</code>. If no byte is available
- * because the end of the stream has been reached, the value
- * <code>-1</code> is returned.
- * <p>
- * The <code>read</code> method of
- * <code>StringBufferInputStream</code> cannot block. It returns the
- * low eight bits of the next character in this input stream's buffer.
- *
- * @return the next byte of data, or <code>-1</code> if the end of the
- * stream is reached.
- * @since JDK1.0
- */
- public synchronized int read() {
- return (pos < count) ? (buffer.charAt(pos++) & 0xFF) : -1;
- }
-
- /**
- * Reads up to <code>len</code> bytes of data from this input stream
- * into an array of bytes.
- * <p>
- * The <code>read</code> method of
- * <code>StringBufferInputStream</code> cannot block. It copies the
- * low eight bits from the characters in this input stream's buffer into
- * the byte array argument.
- *
- * @param b the buffer into which the data is read.
- * @param off the start offset of the data.
- * @param len the maximum number of bytes read.
- * @return the total number of bytes read into the buffer, or
- * <code>-1</code> if there is no more data because the end of
- * the stream has been reached.
- * @since JDK1.0
- */
- public synchronized int read(byte b[], int off, int len) {
- if (pos >= count) {
- return -1;
- }
- if (pos + len > count) {
- len = count - pos;
- }
- if (len <= 0) {
- return 0;
- }
- String s = buffer;
- int cnt = len;
- while (--cnt >= 0) {
- b[off++] = (byte)s.charAt(pos++);
- }
-
- return len;
- }
-
- /**
- * Skips <code>n</code> bytes of input from this input stream. Fewer
- * bytes might be skipped if the end of the input stream is reached.
- *
- * @param n the number of bytes to be skipped.
- * @return the actual number of bytes skipped.
- * @since JDK1.0
- */
- public synchronized long skip(long n) {
- if (n < 0) {
- return 0;
- }
- if (n > count - pos) {
- n = count - pos;
- }
- pos += n;
- return n;
- }
-
- /**
- * Returns the number of bytes that can be read from the input
- * stream without blocking.
- *
- * @return the value of <code>count - pos</code>, which is the
- * number of bytes remaining to be read from the input buffer.
- * @since JDK1.0
- */
- public synchronized int available() {
- return count - pos;
- }
-
- /**
- * Resets the input stream to begin reading from the first character
- * of this input stream's underlying buffer.
- *
- * @since JDK1.0
- */
- public synchronized void reset() {
- pos = 0;
- }
- }
-