org.apache.fop.pdf.PDFStream Maven / Gradle / Ivy
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/*
* 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.
*/
/* $Id: PDFStream.java 1760942 2016-09-15 14:37:18Z ssteiner $ */
package org.apache.fop.pdf;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.Arrays;
/**
* Class representing a PDF stream.
*
* A derivative of the PDF Object, a PDF Stream has not only a dictionary
* but a stream of PDF commands. The stream of commands is where the real
* work is done, the dictionary just provides information like the stream
* length.
*/
public class PDFStream extends AbstractPDFStream {
/**
* The stream of PDF commands
*/
protected StreamCache data;
private transient Writer streamWriter;
private transient char[] charBuffer;
/**
* Create an empty stream object
*/
public PDFStream() {
setUp();
}
public PDFStream(PDFDictionary dictionary) {
super(dictionary);
setUp();
}
public PDFStream(PDFDictionary dictionary, boolean encodeOnTheFly) {
super(dictionary, encodeOnTheFly);
setUp();
}
public PDFStream(boolean encodeOnTheFly) {
super(encodeOnTheFly);
setUp();
}
private void setUp() {
try {
data = StreamCacheFactory.getInstance().createStreamCache();
this.streamWriter = new OutputStreamWriter(
getBufferOutputStream(), PDFDocument.ENCODING);
//Buffer to minimize calls to the converter
this.streamWriter = new java.io.BufferedWriter(this.streamWriter);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
/**
* Append data to the stream
*
* @param s the string of PDF to add
*/
public void add(String s) {
try {
this.streamWriter.write(s);
} catch (IOException ex) {
//TODO throw the exception and catch it elsewhere
ex.printStackTrace();
}
}
/**
* Append data to the stream
*
* @param sb the string buffer of PDF to add
*/
public void add(StringBuffer sb) {
try {
int nHave = sb.length();
if (charBuffer == null) {
charBuffer = new char [ nHave * 2 ];
} else {
int nAvail = charBuffer.length;
if (nAvail < nHave) {
int nAlloc = nAvail;
while (nAlloc < nHave) {
nAlloc *= 2;
}
charBuffer = new char [ nAlloc ];
}
}
sb.getChars(0, nHave, charBuffer, 0);
this.streamWriter.write(charBuffer, 0, nHave);
} catch (IOException ex) {
//TODO throw the exception and catch it elsewhere
ex.printStackTrace();
}
}
private void flush() throws IOException {
this.streamWriter.flush();
}
/**
* Returns a Writer that writes to the OutputStream of the buffer.
* @return the Writer
*/
public Writer getBufferWriter() {
return this.streamWriter;
}
/**
* Returns an OutputStream that can be used to write to the buffer which is used
* to build up the PDF stream.
* @return the OutputStream
* @throws IOException In case of an I/O problem
*/
public OutputStream getBufferOutputStream() throws IOException {
if (this.streamWriter != null) {
flush(); //Just to be sure
}
return this.data.getOutputStream();
}
/**
* Used to set the contents of the PDF stream.
* @param data the contents as a byte array
* @throws IOException in case of an I/O problem
*/
public void setData(byte[] data) throws IOException {
this.data.clear();
this.data.write(data);
}
/**
* Returns the size of the content.
* @return size of the content
*/
public int getDataLength() {
try {
flush();
return data.getSize();
} catch (Exception e) {
//TODO throw the exception and catch it elsewhere
e.printStackTrace();
return 0;
}
}
/** {@inheritDoc} */
protected int getSizeHint() throws IOException {
flush();
return data.getSize();
}
/** {@inheritDoc} */
protected void outputRawStreamData(OutputStream out) throws IOException {
flush();
data.outputContents(out);
}
/**
* {@inheritDoc}
*/
public int output(OutputStream stream) throws IOException {
final int len = super.output(stream);
//Now that the data has been written, it can be discarded.
// this.data = null;
return len;
}
public int streamHashCode() throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
outputRawStreamData(bos);
return Arrays.hashCode(bos.toByteArray());
}
}