org.elasticsearch.common.io.Streams Maven / Gradle / Ivy
/*
* Licensed to ElasticSearch and Shay Banon under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. ElasticSearch 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.elasticsearch.common.io;
import com.google.common.base.Charsets;
import org.elasticsearch.common.Preconditions;
import org.elasticsearch.common.io.stream.BytesStreamOutput;
import org.elasticsearch.common.io.stream.CachedStreamOutput;
import java.io.*;
/**
* Simple utility methods for file and stream copying.
* All copy methods use a block size of 4096 bytes,
* and close all affected streams when done.
*
* Mainly for use within the framework,
* but also useful for application code.
*/
public abstract class Streams {
public static final int BUFFER_SIZE = 1024 * 8;
//---------------------------------------------------------------------
// Copy methods for java.io.File
//---------------------------------------------------------------------
/**
* Copy the contents of the given input File to the given output File.
*
* @param in the file to copy from
* @param out the file to copy to
* @return the number of bytes copied
* @throws IOException in case of I/O errors
*/
public static long copy(File in, File out) throws IOException {
Preconditions.checkNotNull(in, "No input File specified");
Preconditions.checkNotNull(out, "No output File specified");
return copy(new BufferedInputStream(new FileInputStream(in)),
new BufferedOutputStream(new FileOutputStream(out)));
}
/**
* Copy the contents of the given byte array to the given output File.
*
* @param in the byte array to copy from
* @param out the file to copy to
* @throws IOException in case of I/O errors
*/
public static void copy(byte[] in, File out) throws IOException {
Preconditions.checkNotNull(in, "No input byte array specified");
Preconditions.checkNotNull(out, "No output File specified");
ByteArrayInputStream inStream = new ByteArrayInputStream(in);
OutputStream outStream = new BufferedOutputStream(new FileOutputStream(out));
copy(inStream, outStream);
}
/**
* Copy the contents of the given input File into a new byte array.
*
* @param in the file to copy from
* @return the new byte array that has been copied to
* @throws IOException in case of I/O errors
*/
public static byte[] copyToByteArray(File in) throws IOException {
Preconditions.checkNotNull(in, "No input File specified");
return copyToByteArray(new BufferedInputStream(new FileInputStream(in)));
}
//---------------------------------------------------------------------
// Copy methods for java.io.InputStream / java.io.OutputStream
//---------------------------------------------------------------------
public static long copy(InputStream in, OutputStream out) throws IOException {
return copy(in, out, new byte[BUFFER_SIZE]);
}
/**
* Copy the contents of the given InputStream to the given OutputStream.
* Closes both streams when done.
*
* @param in the stream to copy from
* @param out the stream to copy to
* @return the number of bytes copied
* @throws IOException in case of I/O errors
*/
public static long copy(InputStream in, OutputStream out, byte[] buffer) throws IOException {
Preconditions.checkNotNull(in, "No InputStream specified");
Preconditions.checkNotNull(out, "No OutputStream specified");
try {
long byteCount = 0;
int bytesRead;
while ((bytesRead = in.read(buffer)) != -1) {
out.write(buffer, 0, bytesRead);
byteCount += bytesRead;
}
out.flush();
return byteCount;
} finally {
try {
in.close();
} catch (IOException ex) {
// do nothing
}
try {
out.close();
} catch (IOException ex) {
// do nothing
}
}
}
/**
* Copy the contents of the given byte array to the given OutputStream.
* Closes the stream when done.
*
* @param in the byte array to copy from
* @param out the OutputStream to copy to
* @throws IOException in case of I/O errors
*/
public static void copy(byte[] in, OutputStream out) throws IOException {
Preconditions.checkNotNull(in, "No input byte array specified");
Preconditions.checkNotNull(out, "No OutputStream specified");
try {
out.write(in);
} finally {
try {
out.close();
} catch (IOException ex) {
// do nothing
}
}
}
/**
* Copy the contents of the given InputStream into a new byte array.
* Closes the stream when done.
*
* @param in the stream to copy from
* @return the new byte array that has been copied to
* @throws IOException in case of I/O errors
*/
public static byte[] copyToByteArray(InputStream in) throws IOException {
CachedStreamOutput.Entry cachedEntry = CachedStreamOutput.popEntry();
try {
BytesStreamOutput out = cachedEntry.bytes();
copy(in, out);
return out.bytes().copyBytesArray().toBytes();
} finally {
CachedStreamOutput.pushEntry(cachedEntry);
}
}
//---------------------------------------------------------------------
// Copy methods for java.io.Reader / java.io.Writer
//---------------------------------------------------------------------
/**
* Copy the contents of the given Reader to the given Writer.
* Closes both when done.
*
* @param in the Reader to copy from
* @param out the Writer to copy to
* @return the number of characters copied
* @throws IOException in case of I/O errors
*/
public static int copy(Reader in, Writer out) throws IOException {
Preconditions.checkNotNull(in, "No Reader specified");
Preconditions.checkNotNull(out, "No Writer specified");
try {
int byteCount = 0;
char[] buffer = new char[BUFFER_SIZE];
int bytesRead;
while ((bytesRead = in.read(buffer)) != -1) {
out.write(buffer, 0, bytesRead);
byteCount += bytesRead;
}
out.flush();
return byteCount;
} finally {
try {
in.close();
} catch (IOException ex) {
// do nothing
}
try {
out.close();
} catch (IOException ex) {
// do nothing
}
}
}
/**
* Copy the contents of the given String to the given output Writer.
* Closes the write when done.
*
* @param in the String to copy from
* @param out the Writer to copy to
* @throws IOException in case of I/O errors
*/
public static void copy(String in, Writer out) throws IOException {
Preconditions.checkNotNull(in, "No input String specified");
Preconditions.checkNotNull(out, "No Writer specified");
try {
out.write(in);
} finally {
try {
out.close();
} catch (IOException ex) {
// do nothing
}
}
}
/**
* Copy the contents of the given Reader into a String.
* Closes the reader when done.
*
* @param in the reader to copy from
* @return the String that has been copied to
* @throws IOException in case of I/O errors
*/
public static String copyToString(Reader in) throws IOException {
StringWriter out = new StringWriter();
copy(in, out);
return out.toString();
}
public static String copyToStringFromClasspath(ClassLoader classLoader, String path) throws IOException {
InputStream is = classLoader.getResourceAsStream(path);
if (is == null) {
throw new FileNotFoundException("Resource [" + path + "] not found in classpath with class loader [" + classLoader + "]");
}
return copyToString(new InputStreamReader(is, Charsets.UTF_8));
}
public static String copyToStringFromClasspath(String path) throws IOException {
InputStream is = Streams.class.getResourceAsStream(path);
if (is == null) {
throw new FileNotFoundException("Resource [" + path + "] not found in classpath");
}
return copyToString(new InputStreamReader(is, Charsets.UTF_8));
}
public static byte[] copyToBytesFromClasspath(String path) throws IOException {
InputStream is = Streams.class.getResourceAsStream(path);
if (is == null) {
throw new FileNotFoundException("Resource [" + path + "] not found in classpath");
}
return copyToByteArray(is);
}
public static int readFully(Reader reader, char[] dest) throws IOException {
return readFully(reader, dest, 0, dest.length);
}
public static int readFully(Reader reader, char[] dest, int offset, int len) throws IOException {
int read = 0;
while (read < len) {
final int r = reader.read(dest, offset + read, len - read);
if (r == -1) {
break;
}
read += r;
}
return read;
}
public static int readFully(InputStream reader, byte[] dest) throws IOException {
return readFully(reader, dest, 0, dest.length);
}
public static int readFully(InputStream reader, byte[] dest, int offset, int len) throws IOException {
int read = 0;
while (read < len) {
final int r = reader.read(dest, offset + read, len - read);
if (r == -1) {
break;
}
read += r;
}
return read;
}
}