Java tutorial
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); } }