When ArrayList Matched Element Found If condition not run

Question

In android coding i have two different arraylist. i have matched both arraylist elements. But my problem is that when my matched data found in loop, if statement not running. this is my code

for (int i = 0; i < mname.size(); i++) 
{
    if(i<jsonArray.length())
    {
     JSONObject jo = jsonArray.getJSONObject(i);
     String paid = jo.getString("name");
     instname.add(paid);
     }
     else
     {
     instname.add("0");
     }
     System.out.println(instname.get(i)+ "  " + i );
     for(int j=0;j<mname.size();j++)
     {
         System.out.println("instname "+i + "  " + "mname  "+j);
         if(instname.get(i) == mname.get(j))
         {
             System.out.println("instnam=" + instname.get(i));
             System.out.println("mem="+ mname.get(j));
             pay = instname.get(i);
             break;
         }
     }
}

Here in code mname and instname is arraylist. mname has 2 names, 'name1' and 'name2' and instname hase 1 name, 'name2'. In my logcat result like

    name2  0
    instname 0  mname  0
    instname 0  mname  1
    0  1
    instname 1  mname  0
    instname 1  mname  1

instname 0 and mname 1is true matched data contains both name2, but my if condition not run. it results pay = null