com.rt.storage.api.client.util.IOUtils Maven / Gradle / Ivy
package com.rt.storage.api.client.util;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
/**
* Utilities for I/O streams.
*
* @author Yaniv Inbar
* @since 1.14
*/
public class IOUtils {
/**
* Writes the content provided by the given source input stream into the given destination output
* stream.
*
* The input stream is guaranteed to be closed at the end of this method.
*
*
Sample use:
*
*
* static void copy(InputStream inputStream, File file) throws IOException {
* FileOutputStream out = new FileOutputStream(file);
* try {
* IOUtils.copy(inputStream, out);
* } finally {
* out.close();
* }
* }
*
*
* @param inputStream source input stream
* @param outputStream destination output stream
*/
public static void copy(InputStream inputStream, OutputStream outputStream) throws IOException {
copy(inputStream, outputStream, true);
}
/**
* Writes the content provided by the given source input stream into the given destination output
* stream, optionally closing the input stream.
*
* Sample use:
*
*
* static void copy(InputStream inputStream, File file) throws IOException {
* FileOutputStream out = new FileOutputStream(file);
* try {
* IOUtils.copy(inputStream, out, true);
* } finally {
* out.close();
* }
* }
*
*
* @param inputStream source input stream
* @param outputStream destination output stream
* @param closeInputStream whether the input stream should be closed at the end of this method
*/
public static void copy(
InputStream inputStream, OutputStream outputStream, boolean closeInputStream)
throws IOException {
try {
ByteStreams.copy(inputStream, outputStream);
} finally {
if (closeInputStream) {
inputStream.close();
}
}
}
/**
* Computes and returns the byte content length for a streaming content by calling {@link
* StreamingContent#writeTo(OutputStream)} on a fake output stream that only counts bytes written.
*
* @param content streaming content
*/
public static long computeLength(StreamingContent content) throws IOException {
ByteCountingOutputStream countingStream = new ByteCountingOutputStream();
try {
content.writeTo(countingStream);
} finally {
countingStream.close();
}
return countingStream.count;
}
/**
* Serializes the given object value to a newly allocated byte array.
*
* @param value object value to serialize
* @since 1.16
*/
public static byte[] serialize(Object value) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
serialize(value, out);
return out.toByteArray();
}
/**
* Serializes the given object value to an output stream, and close the output stream.
*
* @param value object value to serialize
* @param outputStream output stream to serialize into
* @since 1.16
*/
public static void serialize(Object value, OutputStream outputStream) throws IOException {
try {
new ObjectOutputStream(outputStream).writeObject(value);
} finally {
outputStream.close();
}
}
/**
* Deserializes the given byte array into to a newly allocated object.
*
* @param bytes byte array to deserialize or {@code null} for {@code null} result
* @return new allocated object or {@code null} for {@code null} input
* @since 1.16
*/
public static S deserialize(byte[] bytes) throws IOException {
if (bytes == null) {
return null;
}
return deserialize(new ByteArrayInputStream(bytes));
}
/**
* Deserializes the given input stream into to a newly allocated object, and close the input
* stream.
*
* @param inputStream input stream to deserialize
* @since 1.16
*/
@SuppressWarnings("unchecked")
public static S deserialize(InputStream inputStream) throws IOException {
try {
return (S) new ObjectInputStream(inputStream).readObject();
} catch (ClassNotFoundException exception) {
IOException ioe = new IOException("Failed to deserialize object");
ioe.initCause(exception);
throw ioe;
} finally {
inputStream.close();
}
}
/**
* Returns whether the given file is a symbolic link.
*
* @since 1.16
*/
public static boolean isSymbolicLink(File file) throws IOException {
// first try using Java 7
try {
// use reflection here
Class filesClass = Class.forName("java.nio.file.Files");
Class pathClass = Class.forName("java.nio.file.Path");
Object path = File.class.getMethod("toPath").invoke(file);
return ((Boolean) filesClass.getMethod("isSymbolicLink", pathClass).invoke(null, path))
.booleanValue();
} catch (InvocationTargetException exception) {
Throwable cause = exception.getCause();
Throwables.propagateIfPossible(cause, IOException.class);
// shouldn't reach this point, but just in case...
throw new RuntimeException(cause);
} catch (ClassNotFoundException exception) {
// handled below
} catch (IllegalArgumentException exception) {
// handled below
} catch (SecurityException exception) {
// handled below
} catch (IllegalAccessException exception) {
// handled below
} catch (NoSuchMethodException exception) {
// handled below
}
// backup option compatible with earlier Java
// this won't work on Windows, which is where separator char is '\\'
if (File.separatorChar == '\\') {
return false;
}
File canonical = file;
if (file.getParent() != null) {
canonical = new File(file.getParentFile().getCanonicalFile(), file.getName());
}
return !canonical.getCanonicalFile().equals(canonical.getAbsoluteFile());
}
}