MainActivity.java

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        context = getApplicationContext();

        gcm = GoogleCloudMessaging.getInstance(this);
        registerInBackground();

        webView = (WebView) findViewById(R.id.webview);

        webView.setWebViewClient(new WebViewClient() {
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                if (!url.startsWith("file:") && !url.startsWith("http:") && !url.startsWith("https:")) {
                    webView.stopLoading();

                    Intent intent = new Intent(getApplication(), InfoActivity.class);
                    startActivity(intent);

                    return true;

                }

                return super.shouldOverrideUrlLoading(view, url);
            }
        });

        webView.loadUrl("http://hoge.jp/");
        webView.getSettings().setJavaScriptEnabled(true);
    }