How to read DataInputStream to the end without catching EOFException in Java?

In some cases, when reading the content of the file, if the end of the file is reached in this case, EOFException will be thrown.

Especially, this exception is thrown when reading data with Input stream objects. In other cases, a specific value will be thrown when reaching the end of the file.

In the DataInputStream class, it provides various methods, such asreadboolean(),readByte(),readChar()Etc., the original value read. When using these methods to read data from the file, EOFException will be thrown when reaching the end of the file.

Example

The following program demonstrates how to handle EOFException in Java.

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Scanner;
public class AIOBSample {
　　　public static void main(String[] args) throws Exception {
　　　　　　//Read data from the user
　　　　　　Scanner sc = new Scanner(System.in);
　　　　　　System.out.println("Enter a String: ");
　　　　　　String data = sc.nextLine();
　　　　　　byte[] buf = data.getBytes();
　　　　　　//Write it to the file
　　　　　　DataOutputStream dos = new DataOutputStream(new FileOutputStream("D:\\data.txt"));
　　　　　　for (byte b : buf) {
　　　　　　　　　dos.writeChar(b);
　　　　　　}
　　　　　　dos.flush();
　　　　　　//Reading from the above created file using readChar() method
　　　　　　DataInputStream dis = new DataInputStream(new FileInputStream("D:\\data.txt"));
　　　　　　while(true) {
　　　　　　　　　char ch;
　　　　　　　　　ch = dis.readChar();
　　　　　　　　　System.out.print(ch);
　　　　　　}
　　　}
}

Output Result

Enter a String:
hello how are you
helException in thread "main" lo how are youjava.io.EOFException
　　　at java.io.DataInputStream.readChar(Unknown Source)
　　　at MyPackage.AIOBSample.main(AIOBSample.java:27)

read from DataInputStream without catching an exception

You cannot useDataInputStreamThe class reads the content of the file until it reaches the end of the file. You can use other subclasses of the InputStream interface if needed.

Example

In the following example, we use the FileInputStream class instead of DataInputStream to rewrite the above program to read data from the file.

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Scanner;
public class AIOBSample {
　　　public static void main(String[] args) throws Exception {
　　　　　　//Read data from the user
　　　　　　Scanner sc = new Scanner(System.in);
　　　　　　System.out.println("Enter a String: ");
　　　　　　String data = sc.nextLine();
　　　　　　byte[] buf = data.getBytes();
　　　　　　//Write it to the file
　　　　　　DataOutputStream dos = new DataOutputStream(new FileOutputStream("D:\\data.txt"));
　　　　　　for (byte b : buf) {
　　　　　　　　　dos.writeChar(b);
　　　　　　}
　　　　　　dos.flush();
　　　　　　//Reading from the above created file using readChar() method
　　　　　　File file = new File("D:\\data.txt");
　　　　　　FileInputStream fis = new FileInputStream(file);
　　　　　　byte b[] = new byte[(int) file.length()];
　　　　　　fis.read(b);
　　　　　　System.out.println("contents of the file: ");+new String(b));
　　　}
}

Output Result

Enter a String:
Hello how are you
contents of the file: H e l l o h o w a r e y o u