How to extract all String from all Java files in a Java project?

I need to extract all hard coded Strings values from all Java files in a Java project
Into a Java Constant file

for example

Input

// Java file number 1
public class A {    
    public static void main(String[] args) {
        System.out.println("HardCoded String A");
    }
}

// Java file number 2
public class B {    
    public static void main(String[] args) {
        System.out.println("HardCoded String B");
    }
}

Output

// a Java Constant file
public class MyConstants {  
    public static final String HardCodedString_01 = "HardCoded String A";
    public static final String HardCodedString_02 = "HardCoded String B";   
}

// Java file number 1
public class A {    
    public static void main(String[] args) {
        System.out.println(MyConstants.HardCodedString_01);
    }
}

// Java file number 2
public class B {    
    public static void main(String[] args) {
        System.out.println(MyConstants.HardCodedString_01);
    }
}

I am aware of Externalize Strings for Eclipse
BUT it works over one file not all files

And when i check this post
Extract all string from a java project
I could not find the link of provided presentation

Also i check this post
Externalize strings for Android project
But that is provided for Android projects not Java projects