Mega Code Archive
General IO stream manipulation utilities
<![CDATA[
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.CharArrayWriter;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
/**
* General IO stream manipulation utilities.
* <p>
* This class provides static utility methods for input/output operations.
* <ul>
* <li>closeQuietly - these methods close a stream ignoring nulls and exceptions
* <li>toXxx/read - these methods read data from a stream
* <li>write - these methods write data to a stream
* <li>copy - these methods copy all the data from one stream to another
* <li>contentEquals - these methods compare the content of two streams
* </ul>
* <p>
* The byte-to-char methods and char-to-byte methods involve a conversion step.
* Two methods are provided in each case, one that uses the platform default
* encoding and the other which allows you to specify an encoding. You are
* encouraged to always specify an encoding because relying on the platform
* default can lead to unexpected results, for example when moving from
* development to production.
* <p>
* All the methods in this class that read a stream are buffered internally.
* This means that there is no cause to use a <code>BufferedInputStream</code>
* or <code>BufferedReader</code>. The default buffer size of 4K has been shown
* to be efficient in tests.
* <p>
* Wherever possible, the methods in this class do <em>not</em> flush or close
* the stream. This is to avoid making non-portable assumptions about the
* streams' origin and further use. Thus the caller is still responsible for
* closing streams after use.
* <p>
* Origin of code: Excalibur.
*
* @author Peter Donald
* @author Jeff Turner
* @author Matthew Hawthorne
* @author Stephen Colebourne
* @author Gareth Davis
* @author Ian Springer
* @author Niall Pemberton
* @author Sandy McArthur
* @version $Id: IOUtils.java 481854 2006-12-03 18:30:07Z scolebourne $
*/
public class IOUtils {
// NOTE: This class is focussed on InputStream, OutputStream, Reader and
// Writer. Each method should take at least one of these as a parameter,
// or return one of them.
/**
* The Unix directory separator character.
*/
public static final char DIR_SEPARATOR_UNIX = '/';
/**
* The Windows directory separator character.
*/
public static final char DIR_SEPARATOR_WINDOWS = '\\';
/**
* The system directory separator character.
*/
public static final char DIR_SEPARATOR = File.separatorChar;
/**
* The Unix line separator string.
*/
public static final String LINE_SEPARATOR_UNIX = "\n";
/**
* The Windows line separator string.
*/
public static final String LINE_SEPARATOR_WINDOWS = "\r\n";
/**
* The system line separator string.
*/
public static final String LINE_SEPARATOR;
static {
// avoid security issues
StringWriter buf = new StringWriter(4);
PrintWriter out = new PrintWriter(buf);
out.println();
LINE_SEPARATOR = buf.toString();
}
/**
* The default buffer size to use.
*/
private static final int DEFAULT_BUFFER_SIZE = 1024 * 4;
/**
* Instances should NOT be constructed in standard programming.
*/
public IOUtils() {
super();
}
//-----------------------------------------------------------------------
/**
* Unconditionally close an <code>Reader</code>.
* <p>
* Equivalent to {@link Reader#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
*
* @param input the Reader to close, may be null or already closed
*/
public static void closeQuietly(Reader input) {
try {
if (input != null) {
input.close();
}
} catch (IOException ioe) {
// ignore
}
}
/**
* Unconditionally close a <code>Writer</code>.
* <p>
* Equivalent to {@link Writer#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
*
* @param output the Writer to close, may be null or already closed
*/
public static void closeQuietly(Writer output) {
try {
if (output != null) {
output.close();
}
} catch (IOException ioe) {
// ignore
}
}
/**
* Unconditionally close an <code>InputStream</code>.
* <p>
* Equivalent to {@link InputStream#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
*
* @param input the InputStream to close, may be null or already closed
*/
public static void closeQuietly(InputStream input) {
try {
if (input != null) {
input.close();
}
} catch (IOException ioe) {
// ignore
}
}
/**
* Unconditionally close an <code>OutputStream</code>.
* <p>
* Equivalent to {@link OutputStream#close()}, except any exceptions will be ignored.
* This is typically used in finally blocks.
*
* @param output the OutputStream to close, may be null or already closed
*/
public static void closeQuietly(OutputStream output) {
try {
if (output != null) {
output.close();
}
} catch (IOException ioe) {
// ignore
}
}
/**
* Get the contents of a <code>String</code> as a <code>byte[]</code>
* using the default character encoding of the platform.
* <p>
* This is the same as {@link String#getBytes()}.
*
* @param input the <code>String</code> to convert
* @return the requested byte array
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs (never occurs)
* @deprecated Use {@link String#getBytes()}
*/
public static byte[] toByteArray(String input) throws IOException {
return input.getBytes();
}
// read char[]
//-----------------------------------------------------------------------
/**
* Get the contents of an <code>InputStream</code> as a character array
* using the default character encoding of the platform.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
*
* @param is the <code>InputStream</code> to read from
* @return the requested character array
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static char[] toCharArray(InputStream is) throws IOException {
CharArrayWriter output = new CharArrayWriter();
copy(is, output);
return output.toCharArray();
}
/**
* Get the contents of an <code>InputStream</code> as a character array
* using the specified character encoding.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
*
* @param is the <code>InputStream</code> to read from
* @param encoding the encoding to use, null means platform default
* @return the requested character array
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static char[] toCharArray(InputStream is, String encoding)
throws IOException {
CharArrayWriter output = new CharArrayWriter();
copy(is, output, encoding);
return output.toCharArray();
}
/**
* Get the contents of a <code>Reader</code> as a character array.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedReader</code>.
*
* @param input the <code>Reader</code> to read from
* @return the requested character array
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static char[] toCharArray(Reader input) throws IOException {
CharArrayWriter sw = new CharArrayWriter();
copy(input, sw);
return sw.toCharArray();
}
// read toString
//-----------------------------------------------------------------------
/**
* Get the contents of an <code>InputStream</code> as a String
* using the default character encoding of the platform.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
*
* @param input the <code>InputStream</code> to read from
* @return the requested String
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
*/
public static String toString(InputStream input) throws IOException {
StringWriter sw = new StringWriter();
copy(input, sw);
return sw.toString();
}
/**
* Get the contents of an <code>InputStream</code> as a String
* using the specified character encoding.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
*
* @param input the <code>InputStream</code> to read from
* @param encoding the encoding to use, null means platform default
* @return the requested String
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
*/
public static String toString(InputStream input, String encoding)
throws IOException {
StringWriter sw = new StringWriter();
copy(input, sw, encoding);
return sw.toString();
}
/**
* Get the contents of a <code>Reader</code> as a String.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedReader</code>.
*
* @param input the <code>Reader</code> to read from
* @return the requested String
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
*/
public static String toString(Reader input) throws IOException {
StringWriter sw = new StringWriter();
copy(input, sw);
return sw.toString();
}
/**
* Get the contents of a <code>byte[]</code> as a String
* using the default character encoding of the platform.
*
* @param input the byte array to read from
* @return the requested String
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs (never occurs)
* @deprecated Use {@link String#String(byte[])}
*/
public static String toString(byte[] input) throws IOException {
return new String(input);
}
/**
* Get the contents of a <code>byte[]</code> as a String
* using the specified character encoding.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
*
* @param input the byte array to read from
* @param encoding the encoding to use, null means platform default
* @return the requested String
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs (never occurs)
* @deprecated Use {@link String#String(byte[],String)}
*/
public static String toString(byte[] input, String encoding)
throws IOException {
if (encoding == null) {
return new String(input);
} else {
return new String(input, encoding);
}
}
// readLines
//-----------------------------------------------------------------------
/**
* Get the contents of an <code>InputStream</code> as a list of Strings,
* one entry per line, using the default character encoding of the platform.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
*
* @param input the <code>InputStream</code> to read from, not null
* @return the list of Strings, never null
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static List readLines(InputStream input) throws IOException {
InputStreamReader reader = new InputStreamReader(input);
return readLines(reader);
}
/**
* Get the contents of an <code>InputStream</code> as a list of Strings,
* one entry per line, using the specified character encoding.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
*
* @param input the <code>InputStream</code> to read from, not null
* @param encoding the encoding to use, null means platform default
* @return the list of Strings, never null
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static List readLines(InputStream input, String encoding) throws IOException {
if (encoding == null) {
return readLines(input);
} else {
InputStreamReader reader = new InputStreamReader(input, encoding);
return readLines(reader);
}
}
/**
* Get the contents of a <code>Reader</code> as a list of Strings,
* one entry per line.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedReader</code>.
*
* @param input the <code>Reader</code> to read from, not null
* @return the list of Strings, never null
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static List readLines(Reader input) throws IOException {
BufferedReader reader = new BufferedReader(input);
List list = new ArrayList();
String line = reader.readLine();
while (line != null) {
list.add(line);
line = reader.readLine();
}
return list;
}
//-----------------------------------------------------------------------
/**
* Convert the specified string to an input stream, encoded as bytes
* using the default character encoding of the platform.
*
* @param input the string to convert
* @return an input stream
* @since Commons IO 1.1
*/
public static InputStream toInputStream(String input) {
byte[] bytes = input.getBytes();
return new ByteArrayInputStream(bytes);
}
/**
* Convert the specified string to an input stream, encoded as bytes
* using the specified character encoding.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
*
* @param input the string to convert
* @param encoding the encoding to use, null means platform default
* @throws IOException if the encoding is invalid
* @return an input stream
* @since Commons IO 1.1
*/
public static InputStream toInputStream(String input, String encoding) throws IOException {
byte[] bytes = encoding != null ? input.getBytes(encoding) : input.getBytes();
return new ByteArrayInputStream(bytes);
}
// write byte[]
//-----------------------------------------------------------------------
/**
* Writes bytes from a <code>byte[]</code> to an <code>OutputStream</code>.
*
* @param data the byte array to write, do not modify during output,
* null ignored
* @param output the <code>OutputStream</code> to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(byte[] data, OutputStream output)
throws IOException {
if (data != null) {
output.write(data);
}
}
/**
* Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code>
* using the default character encoding of the platform.
* <p>
* This method uses {@link String#String(byte[])}.
*
* @param data the byte array to write, do not modify during output,
* null ignored
* @param output the <code>Writer</code> to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(byte[] data, Writer output) throws IOException {
if (data != null) {
output.write(new String(data));
}
}
/**
* Writes bytes from a <code>byte[]</code> to chars on a <code>Writer</code>
* using the specified character encoding.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* This method uses {@link String#String(byte[], String)}.
*
* @param data the byte array to write, do not modify during output,
* null ignored
* @param output the <code>Writer</code> to write to
* @param encoding the encoding to use, null means platform default
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(byte[] data, Writer output, String encoding)
throws IOException {
if (data != null) {
if (encoding == null) {
write(data, output);
} else {
output.write(new String(data, encoding));
}
}
}
// write char[]
//-----------------------------------------------------------------------
/**
* Writes chars from a <code>char[]</code> to a <code>Writer</code>
* using the default character encoding of the platform.
*
* @param data the char array to write, do not modify during output,
* null ignored
* @param output the <code>Writer</code> to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(char[] data, Writer output) throws IOException {
if (data != null) {
output.write(data);
}
}
/**
* Writes chars from a <code>char[]</code> to bytes on an
* <code>OutputStream</code>.
* <p>
* This method uses {@link String#String(char[])} and
* {@link String#getBytes()}.
*
* @param data the char array to write, do not modify during output,
* null ignored
* @param output the <code>OutputStream</code> to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(char[] data, OutputStream output)
throws IOException {
if (data != null) {
output.write(new String(data).getBytes());
}
}
/**
* Writes chars from a <code>char[]</code> to bytes on an
* <code>OutputStream</code> using the specified character encoding.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* This method uses {@link String#String(char[])} and
* {@link String#getBytes(String)}.
*
* @param data the char array to write, do not modify during output,
* null ignored
* @param output the <code>OutputStream</code> to write to
* @param encoding the encoding to use, null means platform default
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(char[] data, OutputStream output, String encoding)
throws IOException {
if (data != null) {
if (encoding == null) {
write(data, output);
} else {
output.write(new String(data).getBytes(encoding));
}
}
}
// write String
//-----------------------------------------------------------------------
/**
* Writes chars from a <code>String</code> to a <code>Writer</code>.
*
* @param data the <code>String</code> to write, null ignored
* @param output the <code>Writer</code> to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(String data, Writer output) throws IOException {
if (data != null) {
output.write(data);
}
}
/**
* Writes chars from a <code>String</code> to bytes on an
* <code>OutputStream</code> using the default character encoding of the
* platform.
* <p>
* This method uses {@link String#getBytes()}.
*
* @param data the <code>String</code> to write, null ignored
* @param output the <code>OutputStream</code> to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(String data, OutputStream output)
throws IOException {
if (data != null) {
output.write(data.getBytes());
}
}
/**
* Writes chars from a <code>String</code> to bytes on an
* <code>OutputStream</code> using the specified character encoding.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* This method uses {@link String#getBytes(String)}.
*
* @param data the <code>String</code> to write, null ignored
* @param output the <code>OutputStream</code> to write to
* @param encoding the encoding to use, null means platform default
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(String data, OutputStream output, String encoding)
throws IOException {
if (data != null) {
if (encoding == null) {
write(data, output);
} else {
output.write(data.getBytes(encoding));
}
}
}
// write StringBuffer
//-----------------------------------------------------------------------
/**
* Writes chars from a <code>StringBuffer</code> to a <code>Writer</code>.
*
* @param data the <code>StringBuffer</code> to write, null ignored
* @param output the <code>Writer</code> to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(StringBuffer data, Writer output)
throws IOException {
if (data != null) {
output.write(data.toString());
}
}
/**
* Writes chars from a <code>StringBuffer</code> to bytes on an
* <code>OutputStream</code> using the default character encoding of the
* platform.
* <p>
* This method uses {@link String#getBytes()}.
*
* @param data the <code>StringBuffer</code> to write, null ignored
* @param output the <code>OutputStream</code> to write to
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(StringBuffer data, OutputStream output)
throws IOException {
if (data != null) {
output.write(data.toString().getBytes());
}
}
/**
* Writes chars from a <code>StringBuffer</code> to bytes on an
* <code>OutputStream</code> using the specified character encoding.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* This method uses {@link String#getBytes(String)}.
*
* @param data the <code>StringBuffer</code> to write, null ignored
* @param output the <code>OutputStream</code> to write to
* @param encoding the encoding to use, null means platform default
* @throws NullPointerException if output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void write(StringBuffer data, OutputStream output,
String encoding) throws IOException {
if (data != null) {
if (encoding == null) {
write(data, output);
} else {
output.write(data.toString().getBytes(encoding));
}
}
}
// writeLines
//-----------------------------------------------------------------------
/**
* Writes the <code>toString()</code> value of each item in a collection to
* an <code>OutputStream</code> line by line, using the default character
* encoding of the platform and the specified line ending.
*
* @param lines the lines to write, null entries produce blank lines
* @param lineEnding the line separator to use, null is system default
* @param output the <code>OutputStream</code> to write to, not null, not closed
* @throws NullPointerException if the output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void writeLines(Collection lines, String lineEnding,
OutputStream output) throws IOException {
if (lines == null) {
return;
}
if (lineEnding == null) {
lineEnding = LINE_SEPARATOR;
}
for (Iterator it = lines.iterator(); it.hasNext(); ) {
Object line = it.next();
if (line != null) {
output.write(line.toString().getBytes());
}
output.write(lineEnding.getBytes());
}
}
/**
* Writes the <code>toString()</code> value of each item in a collection to
* an <code>OutputStream</code> line by line, using the specified character
* encoding and the specified line ending.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
*
* @param lines the lines to write, null entries produce blank lines
* @param lineEnding the line separator to use, null is system default
* @param output the <code>OutputStream</code> to write to, not null, not closed
* @param encoding the encoding to use, null means platform default
* @throws NullPointerException if the output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void writeLines(Collection lines, String lineEnding,
OutputStream output, String encoding) throws IOException {
if (encoding == null) {
writeLines(lines, lineEnding, output);
} else {
if (lines == null) {
return;
}
if (lineEnding == null) {
lineEnding = LINE_SEPARATOR;
}
for (Iterator it = lines.iterator(); it.hasNext(); ) {
Object line = it.next();
if (line != null) {
output.write(line.toString().getBytes(encoding));
}
output.write(lineEnding.getBytes(encoding));
}
}
}
/**
* Writes the <code>toString()</code> value of each item in a collection to
* a <code>Writer</code> line by line, using the specified line ending.
*
* @param lines the lines to write, null entries produce blank lines
* @param lineEnding the line separator to use, null is system default
* @param writer the <code>Writer</code> to write to, not null, not closed
* @throws NullPointerException if the input is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void writeLines(Collection lines, String lineEnding,
Writer writer) throws IOException {
if (lines == null) {
return;
}
if (lineEnding == null) {
lineEnding = LINE_SEPARATOR;
}
for (Iterator it = lines.iterator(); it.hasNext(); ) {
Object line = it.next();
if (line != null) {
writer.write(line.toString());
}
writer.write(lineEnding);
}
}
// copy from InputStream
//-----------------------------------------------------------------------
/**
* Copy bytes from an <code>InputStream</code> to an
* <code>OutputStream</code>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
* <p>
* Large streams (over 2GB) will return a bytes copied value of
* <code>-1</code> after the copy has completed since the correct
* number of bytes cannot be returned as an int. For large streams
* use the <code>copyLarge(InputStream, OutputStream)</code> method.
*
* @param input the <code>InputStream</code> to read from
* @param output the <code>OutputStream</code> to write to
* @return the number of bytes copied
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @throws ArithmeticException if the byte count is too large
* @since Commons IO 1.1
*/
public static int copy(InputStream input, OutputStream output) throws IOException {
long count = copyLarge(input, output);
if (count > Integer.MAX_VALUE) {
return -1;
}
return (int) count;
}
/**
* Copy bytes from a large (over 2GB) <code>InputStream</code> to an
* <code>OutputStream</code>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
*
* @param input the <code>InputStream</code> to read from
* @param output the <code>OutputStream</code> to write to
* @return the number of bytes copied
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.3
*/
public static long copyLarge(InputStream input, OutputStream output)
throws IOException {
byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
long count = 0;
int n = 0;
while (-1 != (n = input.read(buffer))) {
output.write(buffer, 0, n);
count += n;
}
return count;
}
/**
* Copy bytes from an <code>InputStream</code> to chars on a
* <code>Writer</code> using the default character encoding of the platform.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
* <p>
* This method uses {@link InputStreamReader}.
*
* @param input the <code>InputStream</code> to read from
* @param output the <code>Writer</code> to write to
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void copy(InputStream input, Writer output)
throws IOException {
InputStreamReader in = new InputStreamReader(input);
copy(in, output);
}
/**
* Copy bytes from an <code>InputStream</code> to chars on a
* <code>Writer</code> using the specified character encoding.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedInputStream</code>.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* This method uses {@link InputStreamReader}.
*
* @param input the <code>InputStream</code> to read from
* @param output the <code>Writer</code> to write to
* @param encoding the encoding to use, null means platform default
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void copy(InputStream input, Writer output, String encoding)
throws IOException {
if (encoding == null) {
copy(input, output);
} else {
InputStreamReader in = new InputStreamReader(input, encoding);
copy(in, output);
}
}
// copy from Reader
//-----------------------------------------------------------------------
/**
* Copy chars from a <code>Reader</code> to a <code>Writer</code>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedReader</code>.
* <p>
* Large streams (over 2GB) will return a chars copied value of
* <code>-1</code> after the copy has completed since the correct
* number of chars cannot be returned as an int. For large streams
* use the <code>copyLarge(Reader, Writer)</code> method.
*
* @param input the <code>Reader</code> to read from
* @param output the <code>Writer</code> to write to
* @return the number of characters copied
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @throws ArithmeticException if the character count is too large
* @since Commons IO 1.1
*/
public static int copy(Reader input, Writer output) throws IOException {
long count = copyLarge(input, output);
if (count > Integer.MAX_VALUE) {
return -1;
}
return (int) count;
}
/**
* Copy chars from a large (over 2GB) <code>Reader</code> to a <code>Writer</code>.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedReader</code>.
*
* @param input the <code>Reader</code> to read from
* @param output the <code>Writer</code> to write to
* @return the number of characters copied
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.3
*/
public static long copyLarge(Reader input, Writer output) throws IOException {
char[] buffer = new char[DEFAULT_BUFFER_SIZE];
long count = 0;
int n = 0;
while (-1 != (n = input.read(buffer))) {
output.write(buffer, 0, n);
count += n;
}
return count;
}
/**
* Copy chars from a <code>Reader</code> to bytes on an
* <code>OutputStream</code> using the default character encoding of the
* platform, and calling flush.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedReader</code>.
* <p>
* Due to the implementation of OutputStreamWriter, this method performs a
* flush.
* <p>
* This method uses {@link OutputStreamWriter}.
*
* @param input the <code>Reader</code> to read from
* @param output the <code>OutputStream</code> to write to
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void copy(Reader input, OutputStream output)
throws IOException {
OutputStreamWriter out = new OutputStreamWriter(output);
copy(input, out);
// XXX Unless anyone is planning on rewriting OutputStreamWriter, we
// have to flush here.
out.flush();
}
/**
* Copy chars from a <code>Reader</code> to bytes on an
* <code>OutputStream</code> using the specified character encoding, and
* calling flush.
* <p>
* This method buffers the input internally, so there is no need to use a
* <code>BufferedReader</code>.
* <p>
* Character encoding names can be found at
* <a href="http://www.iana.org/assignments/character-sets">IANA</a>.
* <p>
* Due to the implementation of OutputStreamWriter, this method performs a
* flush.
* <p>
* This method uses {@link OutputStreamWriter}.
*
* @param input the <code>Reader</code> to read from
* @param output the <code>OutputStream</code> to write to
* @param encoding the encoding to use, null means platform default
* @throws NullPointerException if the input or output is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static void copy(Reader input, OutputStream output, String encoding)
throws IOException {
if (encoding == null) {
copy(input, output);
} else {
OutputStreamWriter out = new OutputStreamWriter(output, encoding);
copy(input, out);
// XXX Unless anyone is planning on rewriting OutputStreamWriter,
// we have to flush here.
out.flush();
}
}
// content equals
//-----------------------------------------------------------------------
/**
* Compare the contents of two Streams to determine if they are equal or
* not.
* <p>
* This method buffers the input internally using
* <code>BufferedInputStream</code> if they are not already buffered.
*
* @param input1 the first stream
* @param input2 the second stream
* @return true if the content of the streams are equal or they both don't
* exist, false otherwise
* @throws NullPointerException if either input is null
* @throws IOException if an I/O error occurs
*/
public static boolean contentEquals(InputStream input1, InputStream input2)
throws IOException {
if (!(input1 instanceof BufferedInputStream)) {
input1 = new BufferedInputStream(input1);
}
if (!(input2 instanceof BufferedInputStream)) {
input2 = new BufferedInputStream(input2);
}
int ch = input1.read();
while (-1 != ch) {
int ch2 = input2.read();
if (ch != ch2) {
return false;
}
ch = input1.read();
}
int ch2 = input2.read();
return (ch2 == -1);
}
/**
* Compare the contents of two Readers to determine if they are equal or
* not.
* <p>
* This method buffers the input internally using
* <code>BufferedReader</code> if they are not already buffered.
*
* @param input1 the first reader
* @param input2 the second reader
* @return true if the content of the readers are equal or they both don't
* exist, false otherwise
* @throws NullPointerException if either input is null
* @throws IOException if an I/O error occurs
* @since Commons IO 1.1
*/
public static boolean contentEquals(Reader input1, Reader input2)
throws IOException {
if (!(input1 instanceof BufferedReader)) {
input1 = new BufferedReader(input1);
}
if (!(input2 instanceof BufferedReader)) {
input2 = new BufferedReader(input2);
}
int ch = input1.read();
while (-1 != ch) {
int ch2 = input2.read();
if (ch != ch2) {
return false;
}
ch = input1.read();
}
int ch2 = input2.read();
return (ch2 == -1);
}
}
]]>