alternative to if statement in java

One "truely object oriented" answer would be to define an interface for "Rule" (with condition() and action() methods), create 3 implementations, stuff them into a collection, and then just iterate through them generically as in:

List<Rule> rules = .... ; // your 3 rules initialized here somehow
for(Rule r : rules) {
  if(r.condition()) {
    r.action();
  }
}

This makes a lot more sense if you have 300 rules/conditions rather than just 3.

In Java8, you may want to do this instead, if the rules are CPU-intensive:

rules.parallelStream().filter(Rule::condition).forEach(Rule::action);

The short answer is yes.

There are a few time you can avoid using if for conditional evluation and branching all together. And they have moments of appropriateness.

1. Polymorphism, when behavior is dependent on the initial values

2. Referrenced Assignment, when you know the possible initial values and they have 1 to 1 correlation with the return values. Lists are better than arrays for this, but...
   

   // Example:  
   if (a==1) { b=2;  }  
   if (a==2) { b=17; }  
   
   // Becomes  
   int fx(2);  // our array of answers  
   fx[0] = 2;   
   fx[1] = 17;  
   b = fx[ a - 1 ];
   

3. Referrenced Branching, when you know the possible initial values and they have 1 to 1 correlation with the function/branch to use. (example not Java)

   // Example:
   if (a==1) { doSomething1();  }  
   if (a==2) { doSomething2(); }  
   
   // Becomes
   function * fx(2);  // our array or better still, list of functions  
   fx[0] = &doSomething1;   
   fx[1] = &doSomething2;  
   `fx[ a - 1 ](); `
   

4. Direct boolean assignment.

   We hate:

   if (thisCondition == true) {  
     b = true;  
   } else {  
     b = false;  
   }
   

   Should be:

   b = thisCondition;

The alternatives to if-else in Java are the switch statement and the conditional ternary (?:) operator, neither of which do exactly what you're asking (handle just an if with no else). The code you posted is the best way to do it, in my opinion.