WebView with upload ability

MainActivity.java

package com.webview;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;


public class MainActivity extends AppCompatActivity {

    //Define URL
    private static final String URL = "http://192.168.1.101/webview/";
    //Define WebView
    private WebView webView;


    private ValueCallback<Uri> mUploadMessage;
    private final static int FILECHOOSER_RESULTCODE=1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        webView = (WebView)findViewById(R.id.webView); //get webView
        webView.setWebViewClient(new WebViewClient()); //set webView client

        //set Upload File function
        webView.setWebChromeClient(new WebChromeClient(){
            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
                mUploadMessage = uploadMsg;
                Intent i = new Intent(Intent.ACTION_GET_CONTENT);
                i.addCategory(Intent.CATEGORY_OPENABLE);
                //set file type
                i.setType("image/*");
                //launch chooser window
                startActivityForResult(Intent.createChooser(i, "File Chooser"), FILECHOOSER_RESULTCODE);
            }
        });

        WebSettings webSettings = webView.getSettings();// initiate webView settings
        webSettings.setJavaScriptEnabled(true); //allow webView perform javascript
        webSettings.setBuiltInZoomControls(true); //show zoom control
        webView.loadUrl(URL); //load URL
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {
        if (requestCode == FILECHOOSER_RESULTCODE) {
            if (null == mUploadMessage)
                return;
            Uri result = intent == null || resultCode != RESULT_OK ? null : intent.getData();
            mUploadMessage.onReceiveValue(result);
            mUploadMessage = null;
        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if (id == R.id.action_exit) {
            //close app when click Close setting menu
            finishApp();
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * Handle Back Navigation Button
     * @param keyCode
     * @param event
     * @return
     */
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {

        if(keyCode == KeyEvent.KEYCODE_BACK && webView.canGoBack()) {
            //back to previous url
            webView.goBack();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

    /**
     * Method to close App
     */
    private void finishApp() {
        finish();
        moveTaskToBack(true);
    }
}