Admin: 1 версия

2010-06-01T06:02:51Z

1 версия

в 18:01, 31 мая 2010

2010-05-31T18:01:43Z

Новая страница

== BufferedWriter out of FileWriter ==



<source lang="java">
/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Sun Microsystems nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class BufferedCopy {
public static void main(String[] args) throws IOException {
BufferedReader inputStream = null;
BufferedWriter outputStream = null;
try {
inputStream = new BufferedReader(new FileReader("xanadu.txt"));
outputStream = new BufferedWriter(new FileWriter("characteroutput.txt"));
int c;
while ((c = inputStream.read()) != -1) {
outputStream.write(c);
}
} finally {
if (inputStream != null) {
inputStream.close();
}
if (outputStream != null) {
outputStream.close();
}
}
}
}
</source>



== Copy Characters between FileReader and FileWriter ==



<source lang="java">
/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Sun Microsystems nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
public class CopyCharacters {
public static void main(String[] args) throws IOException {
FileReader inputStream = null;
FileWriter outputStream = null;
try {
inputStream = new FileReader("xanadu.txt");
outputStream = new FileWriter("characteroutput.txt");
int c;
while ((c = inputStream.read()) != -1) {
outputStream.write(c);
}
} finally {
if (inputStream != null) {
inputStream.close();
}
if (outputStream != null) {
outputStream.close();
}
}
}
}
</source>



== Copy file character by character with FileReader and FileWriter ==



<source lang="java">

import java.io.FileReader;
import java.io.FileWriter;
class FileCopy {
public static void main(String args[]) throws Exception {
FileReader fr = new FileReader(args[0]);
// Create a file writer
FileWriter fw = new FileWriter(args[1]);
// Read and copy characters
int i;
while ((i = fr.read()) != -1) {
fw.write(i);
}
fw.close();
fr.close();
}
}
</source>



== extends FilterWriter and extends FilterReader ==



<source lang="java">
/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Sun Microsystems nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
import java.io.FileReader;
import java.io.FileWriter;
import java.io.FilterReader;
import java.io.FilterWriter;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;
public class CounterDemo {
public static void main(String[] args) throws IOException {
CountReader cr = new CountReader(new FileReader("xanadu.txt"), "e");
CountWriter cw = new CountWriter(new FileWriter("outagain.txt"), "e");
int c = 0;
while ((c = cr.read()) != -1) {
cw.write(c);
}
System.out.println(cr.getCount());
System.out.println(cw.getCount());
cr.close();
cw.close();
}
}
/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name of Sun Microsystems nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
class CountWriter extends FilterWriter {
private int count = 0;
private char lookFor = 0;
public CountWriter(Writer in, char lookFor) {
super(in);
this.lookFor = lookFor;
}
public void write(int character) throws IOException {
super.write(character);
if ((char) character == lookFor) {
count++;
}
}
public void write(char[] cbuf) throws IOException {
super.write(cbuf);
int length = cbuf.length;
for (int i = 0; i < length; i++) {
if (cbuf[i] == lookFor) {
count++;
}
}
}
public void write(char[] cbuf, int off, int len) throws IOException {
super.write(cbuf, off, len);
int length = cbuf.length;
for (int i = 0; i < length; i++) {
if (cbuf[i] == lookFor) {
count++;
}
}
}
public void write(String str) throws IOException {
super.write(str);
int length = str.length();
for (int i = 0; i < length; i++) {
if (str.charAt(i) == lookFor) {
count++;
}
}
}
public void write(String str, int off, int len) throws IOException {
super.write(str, off, len);
int length = str.length();
for (int i = 0; i < length; i++) {
if (str.charAt(i) == lookFor) {
count++;
}
}
}
public int getCount() {
return count;
}
}
/*
* Copyright (c) 1995 - 2008 Sun Microsystems, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name of Sun Microsystems nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
class CountReader extends FilterReader {
private int count = 0;
private char lookFor = 0;
public CountReader(Reader in, char lookFor) {
super(in);
this.lookFor = lookFor;
}
public int read() throws IOException {
int character = super.read();
if ((char) character == lookFor) {
count++;
}
return character;
}
public int read(char[] cbuf) throws IOException {
int numChars = super.read(cbuf);
int length = cbuf.length;
for (int i = 0; i < length; i++) {
if (cbuf[i] == lookFor) {
count++;
}
}
return numChars;
}
public int read(char[] cbuf, int off, int len) throws IOException {
int numChars = super.read(cbuf, off, len);
int length = cbuf.length;
for (int i = 0; i < length; i++) {
if (cbuf[i] == lookFor) {
count++;
}
}
return numChars;
}
public void reset() throws IOException {
super.reset();
count = 0;
}
public boolean markSupported() {
return false;
}
public void mark(int readAheadLimit) throws IOException {
throw new IOException("CountReader does not support the mark() operation.");
}
public int getCount() {
return count;
}
}
</source>



== Write string to file with FileWriter ==



<source lang="java">

import java.io.FileWriter;
class FileWriterDemo {
public static void main(String args[]) throws Exception {
FileWriter fw = new FileWriter(args[0]);
// Write strings to the file
for (int i = 0; i < 12; i++) {
fw.write("Line " + i + "\n");
}
// Close file writer
fw.close();
}
}
</source>

← Предыдущая	Версия 06:02, 1 июня 2010
(нет различий)

Java/File Input Output/FileWriter - История изменений

Admin: 1 версия

в 18:01, 31 мая 2010