Code Works Well in Main Method but When I Try to Give Its Own Method I Get Compiler Error in Regards to IOExceptionWhen Calling the Method

Question

I thank everyone in advance for looking at this and hopefully this is any easy question to answer. I am in the process of learning Java and found a cool piece of code on the internet from http://code.runnable.com/Uu83dm5vSScIAACw/download-a-file-from-the-web-for-java-files-and-save

I modified it to basically call up a Google Static Map and then save it as a jpg. With this code it works perfectly

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;


public class DownloadFile2 {

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

         String fileName = "mapimg.jpg"; //The file that will be     saved on your computer
         URL link = new     URL("http://maps.googleapis.com/maps/api/staticmap?    center=44.667066,+-90.173632&zoom=13&scale=false&size=600x300&maptype=roa    dmap&format=png&visual_refresh=true&markers=size:mid%7Ccolor:0xff0000%7Cl    abel:0%7C44.667066,+-90.173632"); //The file that you want to download

     //Code to download
         InputStream in = new BufferedInputStream(link.openStream());
         ByteArrayOutputStream out = new ByteArrayOutputStream();
         byte[] buf = new byte[1024];
         int n = 0;
         while (-1!=(n=in.read(buf)))
         {
            out.write(buf, 0, n);
         }
         out.close();
         in.close();
         byte[] response = out.toByteArray();

         FileOutputStream fos = new FileOutputStream(fileName);
         fos.write(response);
         fos.close();
     //End download code

         System.out.println("Finished");

    }

}

---

Now this code runs great in the main method. What I am trying to do is put it in its own method and then call it from the main method like such:

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;


public class DownloadFile3 {

    public static void main(String[] args)
    {
        getMap();
    }

    public static void getMap() throws IOException
    {        
         String fileName = "mapimg.jpg"; //The file that will be     saved on your computer
         URL link = new     URL("http://maps.googleapis.com/maps/api/staticmap?    center=44.667066,+-90.173632&zoom=13&scale=false&size=600x300&maptype=roa    dmap&format=png&visual_refresh=true&markers=size:mid%7Ccolor:0xff0000%7Cl    abel:0%7C44.667066,+-90.173632"); //The file that you want to download

     //Code to download
         InputStream in = new BufferedInputStream(link.openStream());
         ByteArrayOutputStream out = new ByteArrayOutputStream();
         byte[] buf = new byte[1024];
         int n = 0;
         while (-1!=(n=in.read(buf)))
         {
            out.write(buf, 0, n);
         }
         out.close();
         in.close();
         byte[] response = out.toByteArray();

         FileOutputStream fos = new FileOutputStream(fileName);
         fos.write(response);
         fos.close();
     //End download code

         System.out.println("Finished");

    }

}

---

It will compile fine without the getMap(); in the main method, but when I call that method, I get the following compiler error, "DownloadFile3.java:13: error: unreported exception IOException; must be caught or declared to be thrown"

I have tried using the try and catch statements and have researched this for days. I'm really stumped on this one and I'm guessing it's probably glaring obvious to a more experienced programmer on here. How come I can get it to work fine in the main method, but in its own method it will not work and give me that error message? Am I calling the method incorrectly or what is going on? I appreciate any help on this.

Answer 1

You have a few choices here. Either...

public static void main(String[] args) throws IOException
{
    getMap();
}

or

public static void main(String[] args)
{
    try {
        getMap();
    } catch (IOException ioe) {
        // do stuff
    }
}

or catch and handle any exceptions in the getMap() method itself. My personal choice would be the second or third option; there's something I don't like about having a main with a throws clause.