QA's approach 2 Java - File Handling -FileInputStream & FileOutputStream Examples

File Handling - Learn through Examples

To have an insights into File Handling theory, follow the link - File Handling Theory  

Byte Stream implementation examples:

Example1. Read Data from file & write to another file using FileInputStream & FileOutputStream

The flow of Data in this example is structured as follows:

Create a package as follows with Input.txt, Output.txt & CopyBytes Class file

We are going to 

Read data from Input.txt to Input Stream & then to CopyBytes.java  

Write data from CopyBytes.java to Output Stream & then to Output.txt file

The below is the Execution logic file - > CopyBytes Class file 

package fileHandling;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;


public class CopyBytes {
public static void main(String[] args) throws IOException {

FileInputStream in = null;
FileOutputStream out = null;
String sourcePath = "C:/Users/user/workspace/New folder/javaForQA/src/fileHandling/Input.txt";
String desctinationPath = "C:/Users/user/workspace/New folder/javaForQA/src/fileHandling/Output.txt";
File sourceFile = null;
try {
// Open Connection of input stream to Input.txt [Source]

sourceFile = new File(sourcePath);

in = new FileInputStream("sourceFile");

// Open Connection of Output stream to Output.txt [Destination]

out = new FileOutputStream("desctinationPath");

int c;

// read data to input stream from Input.txt & then to Program variable 'c'

while ((c = in.read()) != -1) {

// Write the data read from input stream to C to Output stream
// to Output.txt

out.write(c);
}
} finally {
if (in != null) {
in.close();
}
if (out != null) {
out.close();
}
}
}
}

Open Input.txt & write some Text "Input Stream Test Data" & save it.

Execute the Program:

Shift+Alt+x, J

Output.txt file content is overidden by Input.txt file content.