/* | |
* Licensed to the Apache Software Foundation (ASF) under one or more | |
* contributor license agreements. See the NOTICE file distributed with | |
* this work for additional information regarding copyright ownership. | |
* The ASF licenses this file to You under the Apache License, Version 2.0 | |
* (the "License"); you may not use this file except in compliance with | |
* the License. You may obtain a copy of the License at | |
* | |
* http://www.apache.org/licenses/LICENSE-2.0 | |
* | |
* Unless required by applicable law or agreed to in writing, software | |
* distributed under the License is distributed on an "AS IS" BASIS, | |
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
* See the License for the specific language governing permissions and | |
* limitations under the License. | |
*/ | |
package org.apache.struts2.jasper.xmlparser; | |
import org.apache.struts2.jasper.compiler.Localizer; | |
import java.io.IOException; | |
import java.io.InputStream; | |
import java.io.Reader; | |
/** | |
* A simple ASCII byte reader. This is an optimized reader for reading | |
* byte streams that only contain 7-bit ASCII characters. | |
* | |
* @author Andy Clark, IBM | |
* | |
* @version $Id: ASCIIReader.java 466606 2006-10-21 23:07:12Z markt $ | |
*/ | |
public class ASCIIReader | |
extends Reader { | |
// | |
// Constants | |
// | |
/** Default byte buffer size (2048). */ | |
public static final int DEFAULT_BUFFER_SIZE = 2048; | |
// | |
// Data | |
// | |
/** Input stream. */ | |
protected InputStream fInputStream; | |
/** Byte buffer. */ | |
protected byte[] fBuffer; | |
// | |
// Constructors | |
// | |
/** | |
* Constructs an ASCII reader from the specified input stream | |
* and buffer size. | |
* | |
* @param inputStream The input stream. | |
* @param size The initial buffer size. | |
*/ | |
public ASCIIReader(InputStream inputStream, int size) { | |
fInputStream = inputStream; | |
fBuffer = new byte[size]; | |
} | |
// | |
// Reader methods | |
// | |
/** | |
* Read a single character. This method will block until a character is | |
* available, an I/O error occurs, or the end of the stream is reached. | |
* | |
* <p> Subclasses that intend to support efficient single-character input | |
* should override this method. | |
* | |
* @return The character read, as an integer in the range 0 to 127 | |
* (<tt>0x00-0x7f</tt>), or -1 if the end of the stream has | |
* been reached | |
* | |
* @exception IOException If an I/O error occurs | |
*/ | |
public int read() throws IOException { | |
int b0 = fInputStream.read(); | |
if (b0 > 0x80) { | |
throw new IOException(Localizer.getMessage("jsp.error.xml.invalidASCII", | |
Integer.toString(b0))); | |
} | |
return b0; | |
} // read():int | |
/** | |
* Read characters into a portion of an array. This method will block | |
* until some input is available, an I/O error occurs, or the end of the | |
* stream is reached. | |
* | |
* @param ch Destination buffer | |
* @param offset Offset at which to start storing characters | |
* @param length Maximum number of characters to read | |
* | |
* @return The number of characters read, or -1 if the end of the | |
* stream has been reached | |
* | |
* @exception IOException If an I/O error occurs | |
*/ | |
public int read(char ch[], int offset, int length) throws IOException { | |
if (length > fBuffer.length) { | |
length = fBuffer.length; | |
} | |
int count = fInputStream.read(fBuffer, 0, length); | |
for (int i = 0; i < count; i++) { | |
int b0 = fBuffer[i]; | |
if (b0 > 0x80) { | |
throw new IOException(Localizer.getMessage("jsp.error.xml.invalidASCII", | |
Integer.toString(b0))); | |
} | |
ch[offset + i] = (char)b0; | |
} | |
return count; | |
} // read(char[],int,int) | |
/** | |
* Skip characters. This method will block until some characters are | |
* available, an I/O error occurs, or the end of the stream is reached. | |
* | |
* @param n The number of characters to skip | |
* | |
* @return The number of characters actually skipped | |
* | |
* @exception IOException If an I/O error occurs | |
*/ | |
public long skip(long n) throws IOException { | |
return fInputStream.skip(n); | |
} // skip(long):long | |
/** | |
* Tell whether this stream is ready to be read. | |
* | |
* @return True if the next read() is guaranteed not to block for input, | |
* false otherwise. Note that returning false does not guarantee that the | |
* next read will block. | |
* | |
* @exception IOException If an I/O error occurs | |
*/ | |
public boolean ready() throws IOException { | |
return false; | |
} // ready() | |
/** | |
* Tell whether this stream supports the mark() operation. | |
*/ | |
public boolean markSupported() { | |
return fInputStream.markSupported(); | |
} // markSupported() | |
/** | |
* Mark the present position in the stream. Subsequent calls to reset() | |
* will attempt to reposition the stream to this point. Not all | |
* character-input streams support the mark() operation. | |
* | |
* @param readAheadLimit Limit on the number of characters that may be | |
* read while still preserving the mark. After | |
* reading this many characters, attempting to | |
* reset the stream may fail. | |
* | |
* @exception IOException If the stream does not support mark(), | |
* or if some other I/O error occurs | |
*/ | |
public void mark(int readAheadLimit) throws IOException { | |
fInputStream.mark(readAheadLimit); | |
} // mark(int) | |
/** | |
* Reset the stream. If the stream has been marked, then attempt to | |
* reposition it at the mark. If the stream has not been marked, then | |
* attempt to reset it in some way appropriate to the particular stream, | |
* for example by repositioning it to its starting point. Not all | |
* character-input streams support the reset() operation, and some support | |
* reset() without supporting mark(). | |
* | |
* @exception IOException If the stream has not been marked, | |
* or if the mark has been invalidated, | |
* or if the stream does not support reset(), | |
* or if some other I/O error occurs | |
*/ | |
public void reset() throws IOException { | |
fInputStream.reset(); | |
} // reset() | |
/** | |
* Close the stream. Once a stream has been closed, further read(), | |
* ready(), mark(), or reset() invocations will throw an IOException. | |
* Closing a previously-closed stream, however, has no effect. | |
* | |
* @exception IOException If an I/O error occurs | |
*/ | |
public void close() throws IOException { | |
fInputStream.close(); | |
} // close() | |
} // class ASCIIReader |