can not match the String get from properties file in Java

Question

I have a line in file config.properties

clean=true

and use following code to get this property

private static String clean;
Properties prop = new Properties();
try {
    prop.load(new FileInputStream("config.properties"));
    clean = prop.getProperty("clean");
}

I use System.out.println(">"+clean+"<") to see the output and get ">true<", which indicates there is no blank, no \n

However, when I use

if (clean == "true") {          
    // program does not go here
}
else {
    // program goes here
}

what is the possible reason?...

score 0 · Accepted Answer · answered Jun 07 '18 at 04:10

0

Try the following:

== checks if both objects point to the same memory location whereas .equals() evaluates to the comparison of values in the objects.

if (clean.equals("true")) {          
    // program does not go here
}
else {
    // program goes here
}

answered Jun 07 '18 at 04:10

amrender singh

7,949
3
22
28

1

Try not answering again something that gets asked 10 times per day or so. – GhostCat Jun 07 '18 at 04:14
@GhostCat thanks, will keep that in mind from now . – amrender singh Jun 07 '18 at 04:17
@GhostCat Thanks, I have never thought of that. Perhaps I used cpp for so long... – Litchy Jun 07 '18 at 05:15

score 0 · Answer 2 · answered Jun 07 '18 at 04:13

0

The Problem is you are using equality operator which doesn't compare literal instead references. So you have to use equals method to do literal check

if ("true".equals(check)) {          
    // Now Program will go here
}
else {
 // and now here
}

answered Jun 07 '18 at 04:13

Neeraj Jain

7,643
6
34
62

The other problem here is that this is an obvious duplicate. – GhostCat Jun 07 '18 at 04:25

can not match the String get from properties file in Java

2 Answers2