Java में FileInputStream और FileOutputStream
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FileInputStream input = new FileInputStream("file_name");
FileOutputStream output = new FileOutputStream("file_name");
output.write(bytes);Writing Bytes with FileOutputStream
FileOutputStream characters के बजाय एक file में raw bytes लिखता है, इसे images या serialized objects जैसे binary data के लिए सही choice बनाते हुए जहां कोई text encoding apply नहीं होती।
उदाहरण: Writing Bytes with FileOutputStream
import java.io.FileOutputStream;
import java.io.IOException;
public class Main {
public static void main(String[] args) throws IOException {
FileOutputStream out = new FileOutputStream("data.bin");
out.write(65); // raw byte, not text
out.close();
System.out.println("Written");
}
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Reading Bytes with FileInputStream
FileInputStream उसी तरह एक file से raw bytes वापस पढ़ता है, binary round-tripping के लिए FileOutputStream के साथ जोड़ा जाता है — एक String के बजाय एक byte[] buffer में पढ़ते हुए।
उदाहरण: Reading Bytes with FileInputStream
// Import java.io.FileOutputStream so it can be used by its short name
import java.io.FileOutputStream;
// Import java.io.FileInputStream so it can be used by its short name
import java.io.FileInputStream;
import java.io.IOException;
// Define the class Main
public class Main {
// Program entry point: the JVM starts running here
public static void main(String[] args) throws IOException {
// Create a new FileOutputStream object and store it in out
FileOutputStream out = new FileOutputStream("data.bin");
out.write(65);
out.close();
// Create a new FileInputStream object and store it in in
FileInputStream in = new FileInputStream("data.bin");
// Print a line to the console
System.out.println(in.read());
in.close();
}
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Copying Binary Files
एक binary file copy करने का मतलब है एक FileInputStream से chunks में bytes पढ़ना और हर chunk सीधे एक FileOutputStream में लिखना, bytes को कभी text के रूप में interpret किए बिना।
उदाहरण: Copying Binary Files
// Import java.io.FileOutputStream so it can be used by its short name
import java.io.FileOutputStream;
// Import java.io.FileInputStream so it can be used by its short name
import java.io.FileInputStream;
import java.io.IOException;
// Define the class Main
public class Main {
// Program entry point: the JVM starts running here
public static void main(String[] args) throws IOException {
// Create a new FileOutputStream object and store it in out
FileOutputStream out = new FileOutputStream("source.bin");
out.write(new byte[]{1, 2, 3});
out.close();
// Create a new FileInputStream object and store it in in
FileInputStream in = new FileInputStream("source.bin");
FileOutputStream copy = new FileOutputStream("copy.bin");
// Declare buffer and set it to new byte[1024]
byte[] buffer = new byte[1024];
int len;
// Repeat while (len = in.read(buffer)) != -1 is true
while ((len = in.read(buffer)) != -1) {
copy.write(buffer, 0, len);
}
in.close();
copy.close();
System.out.println("Copied");
}
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Auto-Close Try-With-Resources
Try-with-resources byte streams के लिए बिल्कुल वही तरीके से काम करता है जैसे character streams के लिए, copy operation पूरा होने या throw करने पर दोनों input और output streams अपने आप बंद करते हुए।
उदाहरण: Auto-Close Try-With-Resources
import java.io.FileOutputStream;
import java.io.IOException;
public class Main {
public static void main(String[] args) throws IOException {
try (FileOutputStream out = new FileOutputStream("data.bin")) { // auto-closed
out.write(65);
}
System.out.println("Closed automatically");
}
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String to Bytes conversion
String.getBytes() text को raw bytes में convert करता है (एक specified या default charset उपयोग करके) जब आपको एक character-oriented stream के बजाय एक byte-oriented stream से string data लिखनी है।
उदाहरण: String to Bytes conversion
// Import java.io.FileOutputStream so it can be used by its short name
import java.io.FileOutputStream;
// Import java.io.IOException so it can be used by its short name
import java.io.IOException;
// Define the class Main
public class Main {
// Program entry point: the JVM starts running here
public static void main(String[] args) throws IOException {
// Declare bytes and set it to "Hello".getBytes()
byte[] bytes = "Hello".getBytes();
// Try code that might throw an exception
try (FileOutputStream out = new FileOutputStream("text.bin")) {
out.write(bytes);
}
// Print a line to the console
System.out.println("Written as bytes");
}
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- Encoding specify किए बिना text के लिए byte streams उपयोग करना।
- बिना buffering के एक समय में एक byte से एक file पढ़ना, जो धीमा है।
- Streams बंद करना भूल जाना।
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