Reference a method parameter in javadoc

Question

Is there a way to reference one of the method parameters from the method documentation body? Something like:

/**
 * When {@paramref a} is null, we rely on b for the discombobulation.
 *
 * @param a this is one of the parameters
 * @param b another param
 */
void foo(String a, int b)
{...}

Answer 1

That's not possible with standard Javadoc tool. You can reference classes, methods and fields, but not method arguments. I however question the value if it was possible anyway.

Answer 2

I guess you could write your own doclet or taglet to support this behaviour.

Taglet Overview

Doclet Overview

Answer 3

As you can see in the Java Source of the java.lang.String class:

/**
 * Allocates a new <code>String</code> that contains characters from
 * a subarray of the character array argument. The <code>offset</code>
 * argument is the index of the first character of the subarray and
 * the <code>count</code> argument specifies the length of the
 * subarray. The contents of the subarray are copied; subsequent
 * modification of the character array does not affect the newly
 * created string.
 *
 * @param      value    array that is the source of characters.
 * @param      offset   the initial offset.
 * @param      count    the length.
 * @exception  IndexOutOfBoundsException  if the <code>offset</code>
 *               and <code>count</code> arguments index characters outside
 *               the bounds of the <code>value</code> array.
 */
public String(char value[], int offset, int count) {
    if (offset < 0) {
        throw new StringIndexOutOfBoundsException(offset);
    }
    if (count < 0) {
        throw new StringIndexOutOfBoundsException(count);
    }
    // Note: offset or count might be near -1>>>1.
    if (offset > value.length - count) {
        throw new StringIndexOutOfBoundsException(offset + count);
    }

    this.value = new char[count];
    this.count = count;
    System.arraycopy(value, offset, this.value, 0, count);
}

Parameter references are surrounded by <code></code> tags, which means that the Javadoc syntax does not provide any way to do such a thing. (I think String.class is a good example of javadoc usage).

Answer 4

Confirmed that this is one of the dozens of useful features that Javadoc lacks.

However, don't use <code>foo</code> as recommended above; you can use {@code foo}. This is especially good to know when you refer to a generic type such as {@code Iterator<String>} -- sure looks nicer than <code>Iterator&lt;String&gt;</code>, doesn't it!