org.apache.wicket.util.io.Streams Maven / Gradle / Ivy
/*
* 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.wicket.util.io;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.Reader;
import java.net.URL;
import java.net.URLConnection;
import java.util.Properties;
import org.apache.wicket.util.lang.Args;
/**
* Utilities methods for working with input and output streams.
*
* @author Jonathan Locke
* @author Igor Vaynberg
*/
public final class Streams
{
/**
* Writes the input stream to the output stream. Input is done without a Reader object, meaning
* that the input is copied in its raw form. After it is copied it will close the streams.
*
* @param in
* The input stream
* @param out
* The output stream
* @return Number of bytes copied from one stream to the other
* @throws IOException
*/
public static int copyAndClose(final InputStream in, final OutputStream out) throws IOException
{
try
{
return copy(in, out);
}
finally
{
IOUtils.closeQuietly(in);
IOUtils.closeQuietly(out);
}
}
/**
* Writes the input stream to the output stream. Input is done without a Reader object, meaning
* that the input is copied in its raw form.
*
* @param in
* The input stream
* @param out
* The output stream
* @return Number of bytes copied from one stream to the other
* @throws IOException
*/
public static int copy(final InputStream in, final OutputStream out) throws IOException
{
return copy(in, out, 4096);
}
/**
* Writes the input stream to the output stream. Input is done without a Reader object, meaning
* that the input is copied in its raw form.
*
* @param in
* The input stream
* @param out
* The output stream
* @param bufSize
* The buffer size. A good value is 4096.
* @return Number of bytes copied from one stream to the other
* @throws IOException
*/
public static int copy(final InputStream in, final OutputStream out, final int bufSize)
throws IOException
{
if (bufSize <= 0)
{
throw new IllegalArgumentException("The parameter 'bufSize' must not be <= 0");
}
final byte[] buffer = new byte[bufSize];
int bytesCopied = 0;
while (true)
{
int byteCount = in.read(buffer, 0, buffer.length);
if (byteCount <= 0)
{
break;
}
out.write(buffer, 0, byteCount);
bytesCopied += byteCount;
}
return bytesCopied;
}
/**
* Loads properties from an XML input stream into the provided properties object.
*
* @param properties
* The object to load the properties into
* @param inputStream
* @throws IOException
* When the input stream could not be read from
*/
public static void loadFromXml(final Properties properties, final InputStream inputStream)
throws IOException
{
if (properties == null)
{
throw new IllegalArgumentException("properties must not be null");
}
if (inputStream == null)
{
throw new IllegalArgumentException("inputStream must not be null");
}
properties.loadFromXML(inputStream);
}
/**
* Sets the connection to a URL as non-caching and returns the input stream.
*
* @param url
* the url to read from
* @return the input stream for this url
* @throws IOException when a connection cannot be opened
*/
public static InputStream readNonCaching(final URL url) throws IOException
{
Args.notNull(url, "url");
URLConnection urlConnection = url.openConnection();
urlConnection.setUseCaches(false);
InputStream inputStream = urlConnection.getInputStream();
return inputStream;
}
/**
* Reads a stream as a string.
*
* @param in
* The input stream
* @return The string
* @throws IOException
*/
public static String readString(final InputStream in) throws IOException
{
return readString(new BufferedReader(new InputStreamReader(in)));
}
/**
* Reads a string using a character encoding.
*
* @param in
* The input
* @param encoding
* The character encoding of the input data
* @return The string
* @throws IOException
*/
public static String readString(final InputStream in, final CharSequence encoding)
throws IOException
{
return readString(new BufferedReader(new InputStreamReader(in, encoding.toString())));
}
/**
* Reads all input from a reader into a string.
*
* @param in
* The input
* @return The string
* @throws IOException
*/
public static String readString(final Reader in) throws IOException
{
final StringBuilder buffer = new StringBuilder(2048);
int value;
while ((value = in.read()) != -1)
{
buffer.append((char)value);
}
return buffer.toString();
}
/**
* Private to prevent instantiation.
*/
private Streams()
{
}
}