Admin: 1 версия

2010-06-01T05:19:52Z

1 версия

в 17:44, 31 мая 2010

2010-05-31T17:44:27Z

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== Append string to a text file ==



<source lang="java">
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.PrintStream;
public class Main {
public static void main(String[] argv) {
append(new File("c:\\a.txt"), "value");
}
public static void append(File aFile, String content) {
try {
PrintStream p = new PrintStream(new BufferedOutputStream(new FileOutputStream(aFile, true)));
p.println(content);
p.close();
} catch (Exception e) {
e.printStackTrace();
System.err.println(aFile);
}
}
}</source>



== BufferedOutputStream ==

<p>You should always wrap your OutputStream with a BufferedOutputStream for better performance.
The BufferedOutputStream class has two constructors that accept an OutputStream.</p>



<source lang="java">
public BufferedOutputStream (OutputStream out)
public BufferedOutputStream (OutputStream out, int bufferSize)</source>



== Create DataInputStream out of BufferedInputStream ==



<source lang="java">
import java.io.BufferedInputStream;
import java.io.DataInputStream;
import java.io.EOFException;
import java.io.FileInputStream;
import java.io.IOException;
public class PrimeReader {
public static void main(String[] arguments) {
try {
FileInputStream file = new FileInputStream("400primes.dat");
BufferedInputStream buff = new BufferedInputStream(file);
DataInputStream data = new DataInputStream(buff);
try {
while (true) {
int in = data.readInt();
System.out.print(in + " ");
}
} catch (EOFException eof) {
buff.close();
}
} catch (IOException e) {
System.out.println("Error - " + e.toString());
}
}
}</source>



== Create DataOutputStream out of BufferedOutputStream ==



<source lang="java">
import java.io.BufferedOutputStream;
import java.io.DataOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class PrimeWriter {
public static void main(String[] arguments) {
int[] primes = new int[400];
int numPrimes = 0;
int candidate = 2;
while (numPrimes < 400) {
primes[numPrimes] = candidate;
numPrimes++;
candidate++;
}
try {
FileOutputStream file = new FileOutputStream("p.dat");
BufferedOutputStream buff = new BufferedOutputStream(file);
DataOutputStream data = new DataOutputStream(buff);
for (int i = 0; i < 400; i++)
data.writeInt(primes[i]);
data.close();
} catch (IOException e) {
System.out.println("Error - " + e.toString());
}
}
}</source>



== Write byte array to file using BufferedOutputStream ==



<source lang="java">
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream(new File("C:/Demo"));
BufferedOutputStream bos = new BufferedOutputStream(fos);
bos.write("this is a test".getBytes());
bos.flush();
bos.close();
}
}</source>



== Write byte to file using BufferedOutputStream ==



<source lang="java">
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/Demo.txt");
BufferedOutputStream bos = new BufferedOutputStream(fos);
byte b = 66;
// write a character represented by ascii 66 i.e. "B"
bos.write(b);
bos.flush();
bos.close();
}
}</source>



== Write to file using BufferedOutputStream ==



<source lang="java">
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
BufferedOutputStream bufferedOutput = new BufferedOutputStream(new FileOutputStream(
"yourFile.txt"));
bufferedOutput.write("Line one".getBytes());
bufferedOutput.write("\n".getBytes());
bufferedOutput.write(65);
bufferedOutput.close();
}
}</source>

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Admin: 1 версия

в 17:44, 31 мая 2010