InputStream to String and Byte array
/*
* Copyright WizTools.org
* Licensed under the Apache License, Version 2.0:
* http://www.apache.org/licenses/LICENSE-2.0
*/
//package org.wiztools.commons;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.WritableByteChannel;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.MalformedInputException;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Common operations on java.io.Stream objects.
* @author subwiz
*/
public final class StreamUtil {
private static final Logger LOG = Logger.getLogger(StreamUtil.class.getName());
private StreamUtil(){}
private static CharBuffer decodeHelper(byte[] byteArray, int numberOfBytes, java.nio.charset.Charset charset) throws IOException {
CharsetDecoder decoder = charset.newDecoder();
CharBuffer charBuffer = null;
try {
charBuffer = decoder.decode(ByteBuffer.wrap(byteArray, 0,
numberOfBytes));
} catch (MalformedInputException ex) {
charBuffer = null;
}
return charBuffer;
}
/**
* Reads the stream and generates a String content using the charset specified.
* Stream will be closed at the end of the operation.
* @param in InputStream as the input.
* @param charset The charset to use to create the String object.
* @return The output String.
* @throws IOException
*/
public static String inputStream2String(final InputStream is,
final Charset charset) throws IOException {
try{
StringBuilder out = new StringBuilder();
byte[] b = new byte[4096];
byte[] savedBytes = new byte[1];
boolean hasSavedBytes = false;
CharsetDecoder decoder = charset.newDecoder();
for (int n; (n = is.read(b)) != -1;) {
if (hasSavedBytes) {
byte[] bTmp = new byte[savedBytes.length + b.length];
System.arraycopy(savedBytes, 0, bTmp, 0,
savedBytes.length);
System.arraycopy(b, 0, bTmp, savedBytes.length, b.length);
b = bTmp;
hasSavedBytes = false;
n = n + savedBytes.length;
}
CharBuffer charBuffer = decodeHelper(b, n, charset);
if (charBuffer == null) {
int nrOfChars = 0;
while (charBuffer == null) {
nrOfChars++;
charBuffer = decodeHelper(b, n - nrOfChars, charset);
if (nrOfChars > 10 && nrOfChars < n) {
try {
charBuffer = decoder.decode(ByteBuffer.wrap(b,
0, n));
} catch (MalformedInputException ex) {
throw new IOException(
"File not in supported encoding (" +
charset.displayName() + ")", ex);
}
}
}
savedBytes = new byte[nrOfChars];
hasSavedBytes = true;
for (int i = 0; i < nrOfChars; i++) {
savedBytes[i] = b[n - nrOfChars + i];
}
}
charBuffer.rewind(); // Bring the buffer's pointer to 0
out.append(charBuffer.toString());
}
if (hasSavedBytes) {
try {
CharBuffer charBuffer = decoder.decode(ByteBuffer.wrap(savedBytes, 0, savedBytes.length));
} catch (MalformedInputException ex) {
throw new IOException(
"File not in supported encoding (" + charset.displayName() + ")",
ex);
}
}
return out.toString();
}
finally{
if(is != null){
is.close();
}
}
}
/**
* Reads the InputStream and creates a byte[] of the content. The stream
* will be closed at the end of operation.
* @param is The input InputStream.
* @return The byte[] of the content read.
* @throws IOException
*/
public static byte[] inputStream2Bytes(final InputStream is) throws IOException{
try{
ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buf = new byte[1024*8];
int len = -1;
while((len = is.read(buf))!=-1){
baos.write(buf, 0, len);
}
return baos.toByteArray(); // baos doesn't need close!
}
finally{
is.close();
}
}
/**
* Copies the content read from InputStream to OutputStream. Uses the NIO Channels to copy.
* @param is The InputStream that is read.
* @param os The OutputStream where the data is written.
* @throws IOException
*/
public static void copy(final InputStream is, final OutputStream os) throws IOException {
final ReadableByteChannel inChannel = Channels.newChannel(is);
final WritableByteChannel outChannel = Channels.newChannel(os);
try{
final ByteBuffer buffer = ByteBuffer.allocate(65536);
while(true) {
int bytesRead = inChannel.read(buffer);
if(bytesRead == -1) break;
buffer.flip();
while(buffer.hasRemaining()) outChannel.write(buffer);
buffer.clear();
}
}
finally {
try{inChannel.close();}catch(IOException ex){LOG.log(Level.SEVERE, null, ex);}
try{outChannel.close();}catch(IOException ex){LOG.log(Level.SEVERE, null, ex);}
}
}
}
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