Java Method.getName() not matching to string

Question

I've tested this on several different methods. The string I compare s to is exactly the same as the one that shows up in the log file. The apostrophes are to make sure there's no spaces. Anyone know what's going on?

import java.lang.reflect.Method;
import android.util.Log;

public class Button {
    public Button () {
        for(Method m1:MyOtherClass.class.getMethods()) {
        String s = m1.getName();
            if(s == "Update") {
                Log.i("result","true");
            }
            Log.i("test", "'" + s + "'");
        }
    }
}

score 5 · Answer 1 · answered Jul 19 '12 at 01:05

5

Your problem is in:

if(s == "Update")

Replace it with

if (s.equals("Update"))

== compares references when dealing with Objects (like String), not content/value.

answered Jul 19 '12 at 01:05

Dennis Meng

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score 1 · Answer 2 · answered Jul 19 '12 at 01:05

1

Don't compare Strings (or any Objects) by ==. Use s.equals("Update")

== is used to check if references contains same Objects, not if Objects contains same values,

for example

Integer i1=new Integer(1);
Integer i2=new Integer(1);
Integer i3=i1;
//checking references
System.out.println(i1==i2);//false
System.out.println(i1==i3);//true

//checking values
System.out.println(i1.equals(i2));//true
System.out.println(i1.equals(i3));//true

answered Jul 19 '12 at 01:05

Pshemo

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Don't worry. Everyone is comparing Strings this way at first :) – Pshemo Jul 19 '12 at 01:11

score 1 · Answer 3 · answered Jul 19 '12 at 01:06

1

Use equals() method from String class.

answered Jul 19 '12 at 01:06

TeaCupApp

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score 0 · Answer 4 · answered Jul 19 '12 at 01:05

0

Use "Update".equals(s) This does proper value comparison.

answered Jul 19 '12 at 01:05

devang

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Java Method.getName() not matching to string

4 Answers4