If else statement not working for comparison Java

Question

I tried my code in several ways (using equals(), trim()) but the following code block seems to be not working despite the fact it executes the else block only. I am working on several arrays to get the confusion matrix in cross validation.

    for (int x=0; x< clsNames.length; x++)
    {
         System.out.println("class: "+clsNames[x].trim());
         for (int y=0; y<oftarray1.length ;y++) 
         {
            System.out.println("first validation");                            
            System.out.println(clsNames[x]);                       
            System.out.println(oftarray1[y]);                           
            System.out.println(clsName[y]);

         if (oftarray1[y]==  clsNames[x] && clsName[y]==oftarray1[y])
         {
            System.out.println("tp...");
            truePositives++;
            System.out.println("tp : "+truePositives++);                                
         } 
         else if (oftarray1[y]==clsNames[x] && clsName[y]!=oftarray1[y])
        {                                                         
            System.out.println("fn...");
            falseNegatives++;
            System.out.println("fn : "+falseNegatives++);

        } 
        else if (oftarray1[y]!=clsNames[x] && clsName[y]==oftarray1[y])
        {                                
            System.out.println("fp...");
            falsePositives++;
            System.out.println("fp : "+falsePositives++);

         } 
         else 
         {
            System.out.println("tn...");
            trueNegatives++;
            System.out.println("tn : "+trueNegatives++);
         }
      }
   }