antlr java parser tree tokens

Use antlr to get a tree view of a Java piece of code

Let this loop be (save it under ~/workdir/LoopOne.java):

class LoopOne {
    public static void main(String[] args) {
        float x = Float.parseFloat(args[0]);
        while ( 0 - x <= 0){
            x = x - 1;
        }
    }
}

If you want to get it parsed, you can use Antlr (http://www.antlr.org/)

cd ~/workdir

curl -O http://www.antlr.org/download/antlr-4.5-complete.jar
curl -O https://raw.githubusercontent.com/antlr/grammars-v4/master/java8/Java8.g4

In ".bashrc":

export CLASSPATH=".:/home/mrakotomandimby/workdir/antlr-4.5-complete.jar:$CLASSPATH"
alias antlr4='java -Xmx500M -cp ".:/home/mrakotomandimby/workdir/antlr-4.5-complete.jar:$CLASSPATH" org.antlr.v4.Tool'
alias grun='java org.antlr.v4.runtime.misc.TestRig'

antlr4 Java8.g4 
javac LoopOne.java Java8*.java
grun Java8  compilationUnit -tree LoopOne.java
grun Java8  compilationUnit -gui LoopOne.java