I need this for a couple of my apps and the following code was my solution to the problem. Just showing the code inside onCreate. This is a stand alone app to run on any device to return the screen info.
setContentView(R.layout.activity_main);
    txSize = (TextView) findViewById(R.id.tvSize);
    density = (TextView) findViewById(R.id.density);
    densityDpi = (TextView) findViewById(R.id.densityDpi);
    widthPixels = (TextView) findViewById(R.id.widthPixels);
    xdpi = (TextView) findViewById(R.id.xdpi);
    ydpi = (TextView) findViewById(R.id.ydpi);
    Configuration config = getResources().getConfiguration();
    if ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_LARGE) {
        Toast.makeText(this, "Large screen", Toast.LENGTH_LONG).show();
        txSize.setText("Large screen");
    } else if ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_NORMAL) {
        Toast.makeText(this, "Normal sized screen", Toast.LENGTH_LONG)
                .show();
        txSize.setText("Normal sized screen");
    } else if ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_SMALL) {
        Toast.makeText(this, "Small sized screen", Toast.LENGTH_LONG)
                .show();
        txSize.setText("Small sized screen");
    } else if ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_XLARGE) {
        Toast.makeText(this, "xLarge sized screen", Toast.LENGTH_LONG)
                .show();
        txSize.setText("Small sized screen");
    } else {
        Toast.makeText(this,
                "Screen size is neither large, normal or small",
                Toast.LENGTH_LONG).show();
        txSize.setText("Screen size is neither large, normal or small");
    }
    Display display = getWindowManager().getDefaultDisplay();
    DisplayMetrics metrics = new DisplayMetrics();
    display.getMetrics(metrics);
    Log.i(TAG, "density :" + metrics.density);
    density.setText("density :" + metrics.density);
    Log.i(TAG, "D density :" + metrics.densityDpi);
    densityDpi.setText("densityDpi :" + metrics.densityDpi);
    Log.i(TAG, "width pix :" + metrics.widthPixels);
    widthPixels.setText("widthPixels :" + metrics.widthPixels);
    Log.i(TAG, "xdpi :" + metrics.xdpi);
    xdpi.setText("xdpi :" + metrics.xdpi);
    Log.i(TAG, "ydpi :" + metrics.ydpi);
    ydpi.setText("ydpi :" + metrics.ydpi);
And a simple XML file
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity" >
<TextView
    android:id="@+id/tvSize"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
     />
<TextView
    android:id="@+id/density"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
     />
<TextView
    android:id="@+id/densityDpi"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
     />
<TextView
    android:id="@+id/widthPixels"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
     />
<TextView
    android:id="@+id/xdpi"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
     />
<TextView
    android:id="@+id/ydpi"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    />