в 17:43, 31 мая 2010

2010-05-31T17:43:48Z

Admin: 1 версия

2010-05-31T14:31:51Z

1 версия

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== Buffer: hasRemaining() ==



<source lang="java">

import java.io.FileInputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
public class Main {
private static final int BSIZE = 1024;
public static void main(String[] args) throws Exception {
FileChannel fc = new FileInputStream("data.txt").getChannel();
ByteBuffer buff = ByteBuffer.allocate(BSIZE);
fc.read(buff);
buff.flip();
while (buff.hasRemaining())
System.out.print((char) buff.get());
}
}

</source>



== Buffer: limit(int newLimit) ==



<source lang="java">

import static java.lang.Math.ceil;
import static java.lang.Math.min;
import static java.lang.Math.sqrt;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.LongBuffer;
import java.nio.channels.FileChannel;
public class MainClass {
public static void main(String[] args) {
int count = 100;
long[] numbers = new long[count];
for (int i = 0; i < numbers.length; i++) {
numbers[i] = i;
}
File aFile = new File("data.bin");
FileOutputStream outputFile = null;
try {
outputFile = new FileOutputStream(aFile);
} catch (FileNotFoundException e) {
e.printStackTrace(System.err);
System.exit(1);
}
FileChannel file = outputFile.getChannel();
final int BUFFERSIZE = 100;
ByteBuffer buf = ByteBuffer.allocate(BUFFERSIZE);
LongBuffer longBuf = buf.asLongBuffer();
int numberWritten = 0;
while (numberWritten < numbers.length) {
longBuf.put(numbers, numberWritten, min(longBuf.capacity(), numbers.length - numberWritten));
buf.limit(8 * longBuf.position());
try {
file.write(buf);
numberWritten += longBuf.position();
} catch (IOException e) {
e.printStackTrace(System.err);
System.exit(1);
}
longBuf.clear();
buf.clear();
}
try {
System.out.println("File written is " + file.size() + " bytes.");
outputFile.close();
} catch (IOException e) {
e.printStackTrace(System.err);
System.exit(1);
}
}
}

</source>



== Buffer: remaining() ==



<source lang="java">

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.FileNotFoundException;
import java.nio.ByteBuffer;
import java.nio.LongBuffer;
import java.nio.BufferUnderflowException;
import java.nio.channels.FileChannel;
public class MainClass {
public static void main(String[] args) {
File aFile = new File("data.dat");
FileInputStream inFile = null;
try {
inFile = new FileInputStream(aFile);
} catch (FileNotFoundException e) {
e.printStackTrace(System.err);
System.exit(1);
}
FileChannel inChannel = inFile.getChannel();
final int COUNT = 6;
ByteBuffer buf = ByteBuffer.allocate(8 * COUNT);
long[] data = new long[COUNT];
try {
int pos = 0;
while (inChannel.read(buf) != -1) {
try {
((ByteBuffer) (buf.flip())).asLongBuffer().get(data);
pos = data.length;
} catch (BufferUnderflowException e) {
LongBuffer longBuf = buf.asLongBuffer();
pos = longBuf.remaining();
longBuf.get(data, 0, pos);
}
System.out.println();
for (int i = 0; i < pos; i++) {
System.out.printf("%10d", data[i]);
}
buf.clear();
}
System.out.println("\nEOF reached.");
inFile.close();
} catch (IOException e) {
e.printStackTrace(System.err);
System.exit(1);
}
}
}

</source>

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в 17:43, 31 мая 2010

Admin: 1 версия