Apache Velocity Escape Dot Character-CodePudding

I started looking into Velocity for templating, however I can't seem to escape the dot character after a variable name. Below is the template I have.

## function.vm
void functionA() {
    int minimum_value = $class_name.MIN_VALUE;
    int maximum_value = $class_name.MAX_VALUE;
}

Where $class_name is a variable that I set in the VelocityContext as below.

VelocityContext velocityContext = new VelocityContext();
velocityContext.put("class_name", "Short");

However, this would output the below, no change.

void functionA() {
    int minimum_value = $class_name.MIN_VALUE;
    int maximum_value = $class_name.MAX_VALUE;
}

Adding a back-slash before the dot character $class_name\.MIN_VALUE would replace the variable, but it would also print the back-slash as well, as below.

void functionA() {
    int minimum_value = Short\.MIN_VALUE;
    int maximum_value = Short\.MAX_VALUE;
}

Is escaping not done with a back-slash? I found multiple answers saying it should be with a back-slash, others with using $esc.java() but that didn't work as well.

CodePudding user response：

You can use curly-braces around class_name like:

## function.vm
void functionA() {
    int minimum_value = ${class_name}.MIN_VALUE;
    int maximum_value = ${class_name}.MAX_VALUE;
}

This generates the below output:

void functionA() {
    int minimum_value = Short.MIN_VALUE;
    int maximum_value = Short.MAX_VALUE;
}