BufferedWriter flush() in Java

flush(): This method is available in the java.io.BufferedWriter class of Java.

Syntax:

void java.io.BufferedWriter.flush() throws IOException

This method flushes the stream.

Parameters: NA

Returns: NA

Throws:

IOException - If an I/O error occurs

Approach 1: When no exception

Java

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

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

        FileWriter fileWriter = new FileWriter("D:\\hello.txt");
        BufferedWriter bufferedWriter = 
                          new BufferedWriter(fileWriter);

        bufferedWriter.flush();

        System.out.println("Successfully flushes buffer stream");
        bufferedWriter.close();
    }
}

Output:

Successfully flushes buffer stream

Approach 2: IOException

Java

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

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

        FileWriter fileWriter = new FileWriter("D:\\hello.txt");
        BufferedWriter bufferedWriter = 
                     new BufferedWriter(fileWriter);

        bufferedWriter.close();
        bufferedWriter.flush();

        System.out.println("Successfully flushes buffer stream");

    }
}

Output:

Exception in thread "main" java.io.IOException: Stream closed
	at java.base/java.io.BufferedWriter.ensureOpen(BufferedWriter.java:107)
	at java.base/java.io.BufferedWriter.flushBuffer(BufferedWriter.java:117)
	at java.base/java.io.BufferedWriter.flush(BufferedWriter.java:256)