Code Snippets:File Operations

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

public class FileOperation {

/**
* @param args
*/
public static void main(String[] args) {
FileOperation fio = new FileOperation();
//Creating a source file
File sourceFile=new File("test.txt");
//Creating a destination file
File destinationFile=new File("testDest.txt");

// Writing to a file
fio.writeFile("test.txt", "Writing inside files is fun.");
// Reading from a file
fio.readFile("test.txt");
// Copy from a source file to a destination file
fio.copyFile(sourceFile, destinationFile);

}

// Read from a file
void readFile(String fileName) {
BufferedReader bufferedReader;
String line;

try {
bufferedReader = new BufferedReader(new FileReader(fileName));

while ((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
bufferedReader.close();
} catch (IOException e) {
System.out.println("Error reading file");
}

}

// Write to a file
void writeFile(String fileName, String aText) {
BufferedWriter bufferedWriter;

try {
// FileWriter(fileName,true) constructor allows to append
// the data at the end of the file
bufferedWriter = new BufferedWriter(new FileWriter(fileName, true));
bufferedWriter.append(aText);
bufferedWriter.close();
} catch (IOException e) {
System.out.println("Error writing to file");
}
}

// copy from source file to destination file
void copyFile(File fileSource, File fileDestination) {
// Declare variables
InputStream inputStream = null;
OutputStream outputStream = null;

try {
// Declare variables
int nLen = 0;
inputStream = new FileInputStream(fileSource);
outputStream = new FileOutputStream(fileDestination);

// Transfer bytes from in to out
byte[] bBuffer = new byte[1024];
while ((nLen = inputStream.read(bBuffer)) > 0) {
outputStream.write(bBuffer, 0, nLen);
}

// Flush
outputStream.flush();
} catch (IOException e) {
System.out.println("Error while copying file");
}

finally {
// Close streams
try {
if (inputStream != null)
inputStream.close();
if (outputStream != null)
outputStream.close();
} catch (IOException eError) {
}
}

}
}