are true and false keywords in java?

by

No, true and false are not keywords in java. They are literals in java. As literals are reserved words in java so we cannot use them as identifiers in our program.
Example

public class Main {
        public static void main(String args[]){
              int true = 10;
              String false = "jai";
        }  
}

Output

Main.java:3: error: not a statement
              int true = 10;
              ^
Main.java:3: error: ';' expected
              int true = 10;
                 ^
Main.java:4: error: not a statement
              String false = "jai";
              ^
Main.java:4: error: ';' expected
              String false = "jai";
                    ^
4 errors