Default constructor cannot handle exception type SocketException thrown by implicit super constructor

Question

I'm working on an android app that will be able to switch between 3G and 4G manually by making a call and sending out a package simultaneously. When I end the call, the package will continue to send keeping the phone in 3G, but then when I push a button, it terminates the package.

I'm fine on most of the code, but I got the program to send the package from someone else and I'm a bit confused on how I get it running, specifically this one error I'm getting when I declare the field socket. I get an error message saying "Default constructor cannot handle exception type SocketException thrown by implicit super constructor. Must define an explicit constructor."

Here's my class file for the package:

package com.example.derpphone;

import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.util.TimerTask;
public class timer extends TimerTask {


    DatagramSocket socket = new DatagramSocket();
    @Override
    public void run() {     
                if (socket != null) {
                                   byte[] bytes = new byte[100];
                    SocketAddress serverAddress = new InetSocketAddress("131.179.176.74",
                            9998);
                    try {
                        DatagramPacket packet = new DatagramPacket(bytes,
                                bytes.length, serverAddress);
                        socket.send(packet);                    

                    } catch (Exception e) {

                    }
                }
            }
}

Answer 1

Change your code to:

DatagramSocket socket; 

public timer() throws Exception {
    socket = new DatagramSocket();
}

When you write:

DatagramSocket socket = new DatagramSocket();

without a default constructor, it is equivalent to:

DatagramSocket socket;

public timer() {  
    super();
    socket = new DatagramSocket();
}

As DatagramSocket constructor throws an exception, this needs to be caught or declared.

Answer 2

it means that

DatagramSocket socket = new DatagramSocket();

could throw an SocketException, because default constructor DatagramSocket() declares so, It must be handled or re-throw back, and there is no way to handle it like this so you would nee a constructor around it

change it to

DatagramSocket socket;

public timer throws SocketException { 
    this.socket = new DatagramSocket();
}