Generally we add layout from xml but sometimes we need to add layout using java. Here I am adding linear layout from java file. I am creating LinearLayout class which is provided by Android and add params on it. We have methods to set orientation, gravity etc.

public class DynamicLayoutActivity extends Activity { 
    LinearLayout dynamicLinearLayout; 
    TextView text; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        dynamicLinearLayout = new LinearLayout(this); 
        dynamicLinearLayout.setOrientation(LinearLayout.VERTICAL); 
        LayoutParams layoutParam = new LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, 
LinearLayout.LayoutParams.MATCH_PARENT); 
        dynamicLinearLayout.setLayoutTexts(text); 
        text = new TextView(this); 
        text.setLayoutTexts(new LayoutTexts(LinearLayout.LayoutTexts.MATCH_PARENT, 
LinearLayout.LayoutTexts.WRAP_CONTENT)); 
        text.setText("Dynamic Layout.. Yesssss."); 
        text.setGravity(Gravity.CENTER); 
        dynamicLinearLayout.addView(text); 
       setContentView(dynamicLinearLayout); 
    } 
  }