Shailesh Shukla Android Life: February 2012

Wednesday, February 29, 2012

How do I convert InputStream to String in android?

public class StreamToString {

    public static void main(String[] args) throws Exception {
        StreamToString sts = new StreamToString();

        /*
         * Get input stream of our data file. This file can be in
         * the root of you application folder or inside a jar file
         * if the program is packed as a jar.
         */
        InputStream is = sts.getClass().getResourceAsStream("/data.txt");

        /*
         * Call the method to convert the stream to string
         */
        System.out.println(sts.convertStreamToString(is));
    }

    public String convertStreamToString(InputStream is)
            throws IOException {
        /*
         * To convert the InputStream to String we use the
         * Reader.read(char[] buffer) method. We iterate until the
         * Reader return -1 which means there's no more data to
         * read. We use the StringWriter class to produce the string.
         */
        if (is != null) {
            Writer writer = new StringWriter();

            char[] buffer = new char[1024];
            try {
                Reader reader = new BufferedReader(
                        new InputStreamReader(is, "UTF-8"));
                int n;
                while ((n = reader.read(buffer)) != -1) {
                    writer.write(buffer, 0, n);
                }
            } finally {
                is.close();
            }
            return writer.toString();
        } else {        
            return "";
        }
    }
}

How do I convert String to Date object in android?

public class StringToDate {

    public static void main(String[] args) {
        DateFormat df = new SimpleDateFormat("dd/MM/yyyy");

        try {
            Date today = df.parse("20/12/2005");
            System.out.println("Today = " + df.format(today));
        } catch (ParseException e) {
            e.printStackTrace();
        }
    }
}

Below is the Result

Today = 20/12/2005

How to get HTML content of URL open in Android Webview?

In OnCreate method copy the below code and the desire'd URL....

mWebView = (WebView) findViewById(R.id.webview);
mWebView.getSettings().setJavaScriptEnabled(true);
mWebView.addJavascriptInterface(new MyJavaScriptInterface(), "HTMLOUT");

progressDialog.ShowProgressDialog(0, getString(R.string.Loading_data));

mWebView.setWebViewClient(new WebViewClient() {
public boolean shouldOverrideUrlLoading(WebView view, String url) {
mWebView.loadUrl(url);
return false;
}

@Override
public void onPageStarted(WebView view, String url, Bitmap favicon){
}

public void onReceivedError(WebView view, int errorCode, String description, String failingUrl){
progressDialog.CloseProgressDialog();
}

@Override
public void onPageFinished(WebView view, String url) {
progressDialog.CloseProgressDialog();
mWebView.loadUrl("javascript:window.HTMLOUT.showHTML('<head>'+document.getElementsByTagName('html')[0].innerHTML+'</head>');");

}
});
mWebView.loadUrl(selectedSocial);

And below is the method which we have registered will give the html content in String.......

/* An instance of this class will be registered as a JavaScript interface */
class MyJavaScriptInterface {
public void showHTML(String html) {
String htmlString = html;
}
}

Tuesday, February 28, 2012

HowTo: Get the selected list index on Android Activity from context menu event?

Consider
the situation where you have an Activity displaying a list of items.
You have a context menu and a normal option menu. When pressing the
option menu button, you can get the selected item and index as
follows:

//the selected index
int index = listView.getSelectedItemPosition();
//selected item
Object selObj = listView.getSelectedItem();

It is as simple as that. If you registered a context menu on the list, then the situation changes slightly and the "getSelectedItemPosition()" will fail. Instead, you have to do something like this

AdapterView.AdapterContextMenuInfo menuInfo;
menuInfo = (AdapterView.AdapterContextMenuInfo)item.getMenuInfo();
int index = menuInfo.position;

Example for SensorListener in Android?

public class

TestActivity
extends

Activity
implements

SensorEventListener
{

private

SensorManager
mgr;

private

Sensor
sensorAccelerometer;

private long lastUpdate;

private float

lastX
= 0.5f;

private float

lastY
= 0.5f;

private float

lastZ
= 0.9f;

@Override

protected void

onCreate(Bundle
savedInstanceState) {

super.onCreate(savedInstanceState);

setActionBarContentView(R.layout.testactivity);

mgr
= (SensorManager)getSystemService(SENSOR_SERVICE);

sensorAccelerometer
= mgr.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);

}

@Override

protected void

onResume()
{

super.onResume();

mgr.registerListener(this,
sensorAccelerometer, SensorManager.SENSOR_DELAY_UI);

}

@Override

protected void

onPause()
{

super.onPause();

mgr.unregisterListener(this);

}

@Override

public void

onAccuracyChanged(Sensor
sensor, int

accuracy)
{

//
TODO Auto-generated method stub

}

@Override

public void

onSensorChanged(SensorEvent
event) {

if(event.sensor.getType()
== Sensor.TYPE_ACCELEROMETER){

long

currTime
= System.currentTimeMillis();

if((currTime
- lastUpdate) > 1000){ //just scan every second

lastUpdate
= currTime;

float

xAxis
= event.values[SensorManager.DATA_X];

float

yAxis
= event.values[SensorManager.DATA_Y];

float

zAxis
= event.values[SensorManager.DATA_Z];

String
comment = inMovement(xAxis, yAxis, zAxis) ? "not moving"

:
"in movement";

publishValues(xAxis,
yAxis, zAxis, comment);

lastX
= xAxis;

lastY
= yAxis;

lastZ
= zAxis;

}

private boolean inMovement(float

xAxis,
float

yAxis,
float

zAxis)
{

final float

tolerance
= 0.5f;

if(Math.abs(xAxis
- lastX) <= tolerance && Math.abs(yAxis - lastY) <=
tolerance && Math.abs(zAxis - lastZ)<=tolerance){

return true;

}else

return false;

}

private void publishValues(float

x,
float

y,
float

z,
String comment) {

TextView
mainText =(TextView)findViewById(R.id.textView);

mainText.setText("X:
"

+
x + " - Y: "

+
y + " - Z: "

+
z + "\nComment: "

+
comment);

}