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2010-06-01T05:20:35Z

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в 17:44, 31 мая 2010

2010-05-31T17:44:27Z

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== Create DataOutputStream from BufferedOutputStream ==



<source lang="java">
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class MainClass {
public static void main(String[] args) throws IOException {
DataOutputStream out2 = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(
"Data.txt")));
out2.writeDouble(3.14159);
out2.writeUTF("Square root of 2");
out2.close();
DataInputStream in5 = new DataInputStream(new BufferedInputStream(new FileInputStream(
"Data.txt")));
System.out.println(in5.readDouble());
System.out.println(in5.readUTF());
}
}</source>



== Create DataOutputStream from ByteArrayOutputStream ==



<source lang="java">
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class MainClass {
public static void main(String args[]) throws IOException {
int howMany = 20;
// To avoid resizing the buffer, calculate the size of the
// byte array in advance.
ByteArrayOutputStream bout = new ByteArrayOutputStream(howMany * 4);
DataOutputStream dout = new DataOutputStream(bout);
for (int i = 0; i <= 20; i++) {
dout.writeInt(i);
}
FileOutputStream fout = new FileOutputStream("fibonacci.dat");
try {
bout.writeTo(fout);
fout.flush();
} finally {
fout.close();
}
}
}</source>



== DataOutputStream and DataInputStream: write and read primitive data type to a file ==



<source lang="java">
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception{
int idA = 1;
String nameA = "City";
int populationA = 5;
float tempA = 1.0f;
int idB = 2;
String nameB = "S";
int populationB = 2;
float tempB = 1.45f;
FileOutputStream fos = new FileOutputStream("cities.dat");
DataOutputStream dos = new DataOutputStream(fos);
dos.writeInt(idA);
dos.writeUTF(nameA);
dos.writeInt(populationA);
dos.writeFloat(tempA);
dos.writeInt(idB);
dos.writeUTF(nameB);
dos.writeInt(populationB);
dos.writeFloat(tempB);
dos.flush();
dos.close();
FileInputStream fis = new FileInputStream("cities.dat");
DataInputStream dis = new DataInputStream(fis);
int cityId = dis.readInt();
System.out.println("City Id: " + cityId);
String cityName = dis.readUTF();
System.out.println("City Name: " + cityName);
int cityPopulation = dis.readInt();
System.out.println("City Population: " + cityPopulation);
float cityTemperature = dis.readFloat();
System.out.println("City Temperature: " + cityTemperature);
}
}</source>



== Determine number of bytes written to DataOutputStream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/Bytes.txt");
DataOutputStream dos = new DataOutputStream(fos);
dos.writeBytes("this is a test");
int bytesWritten = dos.size();
System.out.println("Total " + bytesWritten + " bytes are written to stream.");
dos.close();
}
}</source>



== Flush output stream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/WriteByte.txt");
DataOutputStream dos = new DataOutputStream(fos);
dos.writeBytes("this is a test");
dos.flush();
dos.close();
}
}</source>



== Write boolean to a file using DataOutputStream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/WriteBoolean.txt");
DataOutputStream dos = new DataOutputStream(fos);
boolean b = false;
dos.writeBoolean(b);
dos.close();
}
}</source>



== Write byte to a file using DataOutputStream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/WriteByte.txt");
DataOutputStream dos = new DataOutputStream(fos);
int i = 1;
dos.writeByte(i);
dos.close();
}
}</source>



== Write char to a file using DataOutputStream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/WriteChar.txt");
DataOutputStream dos = new DataOutputStream(fos);
int ch = 65;
dos.writeChar(ch);
dos.close();
}
}</source>



== Write double and UTF string using DataOutputStream with BufferedOutputStream backended ==



<source lang="java">
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
public class MainClass {
public static void main(String[] args) throws IOException {
DataOutputStream out2 = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(
"Data.txt")));
out2.writeDouble(3.14159);
out2.writeUTF("Square root of 2");
out2.close();
DataInputStream in5 = new DataInputStream(new BufferedInputStream(new FileInputStream(
"Data.txt")));
System.out.println(in5.readDouble());
System.out.println(in5.readUTF());
}
}</source>



== Write float to a file using DataOutputStream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/WriteFloat.txt");
DataOutputStream dos = new DataOutputStream(fos);
float f = 5.314f;
dos.writeFloat(f);
dos.close();
}
}</source>



== Write integers using DataOutputStream ==



<source lang="java">
import java.io.BufferedOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
public class MainClass {
public static void main(String[] args) throws IOException {
DataOutputStream dos = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(
new File("temp.tmp"))));
for (int i = 0; i < 10; i++)
dos.writeInt(i);
dos.close();
}
}</source>



== Write int to a file using DataOutputStream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception{
FileOutputStream fos = new FileOutputStream("C:/Int.txt");
DataOutputStream dos = new DataOutputStream(fos);
int i = 100;
dos.writeInt(i);
dos.close();
}
}</source>



== Write long to a file using DataOutputStream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/WriteLong.txt");
DataOutputStream dos = new DataOutputStream(fos);
long l = 65;
dos.writeLong(l);
dos.close();
}
}</source>



== Write short to a file using DataOutputStream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/WriteShort.txt");
DataOutputStream dos = new DataOutputStream(fos);
short s = 1;
dos.writeShort(s);
dos.close();
}
}</source>



== Write String as bytes to a file using DataOutputStream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/Bytes.txt");
DataOutputStream dos = new DataOutputStream(fos);
String str = "this is test";
dos.writeBytes(str);
dos.close();
}
}</source>



== Write String as characters to a file using DataOutputStream ==



<source lang="java">
import java.io.DataOutputStream;
import java.io.FileOutputStream;
public class Main {
public static void main(String[] args) throws Exception {
FileOutputStream fos = new FileOutputStream("C:/Chars.txt");
DataOutputStream dos = new DataOutputStream(fos);
String str = "this is a test";
dos.writeChars(str);
dos.close();
}
}</source>

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Admin: 1 версия

в 17:44, 31 мая 2010