Eclipse方法调用重构

Question

I'm trying to refactor some code in the following pattern:

// from
object1.foo(object2).bar() ;

// to
fooBar(object1, object2) ;

where

• object1 is a subtype of SuperClass
• object2 is a String
• fooBar is in a utilities class which needs to be imported

For context, the change is due to foo() returning null in some cases, which leads to NullPointerExceptions when bar() is called.
fooBar() first checks if null would be returned by foo(), and if so returns a default value, else calls bar() and returns that.

I'm using Eclipse, and I'm wondering if there is a good way to do this, instead of manually changing every occurrence using regex in a File Search or something.

EDIT - more info in response to comments:

I do not have control over the implementation of foo().

Regarding object1 being a subclass of SuperClass:

//in some cases this happens
SuperClass object1 = new SuperClass(/*whatever*/) ;

//in other cases this happens
ChildClass object1 = new ChildClass (/*whatever*/) ;

I though I should mention it, as it might affect how to search for object1.

A [maybe] clearer version of before and after code:

//before
Object result = object1.foo("a string").bar() ;
//NullPointerException if foo() returns null! :(

//after
Object result = fooBar(object1, "a string") ;

Meanwhile, in a separate utility class, there exists:

public static Object fooBar(SuperClass obj, String str) {
    Object result = DEFAULT_RESULT ;

    if (obj != null && str != null && obj.fooAble(str)) {
        result = obj.foo(str).bar() ;
    }

    return result ;
}

Answer 1

I found solution even spent on this 3 years of my life! :)

Actually solution based on code refactoring that replaces one method call with another. Example: Before we have: obj1.method1(){}; obj2.method2(obj1){ obj1.method1(); };

After applying eclipse refactoring "Inline ..." we will have every call of obj2.method2(obj1); replaced with call obj1.method1();

So for your case:

1. Make backup copy of source files with implementation of method foo, bar, fooBar;
2. Then replace implementation of fooBar as: fooBar(object1, object2) { return this; };
3. Replace implementation of method bar() with: bar() { return this; };
4. Replace implementation of method foo(object2) with: foo(object2) { return fooBar(this,object2); };
5. Then apply to any call of bar() eclipse refactoring "Inline ...", it just dissolves all bar() calls;
6. Apply again "Inline ..." for any call of object1.foo(object2) which replace all such calls with fooBar(this,object2);
7. Restore implementation of each method from backup copy;

That's it!