Summary

Specify the maximum "ArgumentIndex" limit for java.text.MessageFormat.

Problem

java.text.MessageFormat may define an implementation limit on the maximum "ArgumentIndex" value accepted. The OpenJDK implements a limit of 10,000 for this value. This info should be documented.

Solution

Make apparent in the class description that constructors and methods that take an "ArgumentIndex" value may throw an IllegalArgumentException if the limit is violated. Clarify that this implementation has a limit of 10,000.

Specification

In the pattern description, update the "ArgumentIndex" wording as well as add the implNote tag,

- * The <i>ArgumentIndex</i> value is a non-negative integer written
+ * The {@code ArgumentIndex} value is a non-negative integer written
  * using the digits {@code '0'} through {@code '9'}, and represents an index into the
  * {@code arguments} array passed to the {@code format} methods
  * or the result array returned by the {@code parse} methods.
  * <p>
- * The <i>FormatType</i> and <i>FormatStyle</i> values are used to create
+ * Any constructor or method that takes a String pattern parameter will throw an {@code IllegalArgumentException} if the
+ * pattern contains an {@code ArgumentIndex} value that is equal to or exceeds an implementation limit.
+ * <p>
+ * The {@code FormatType} and {@code FormatStyle} values are used to create
  * a {@code Format} instance for the format element. The following
  * table shows how the values map to {@code Format} instances. These values
  * are case-insensitive when passed to {@link #applyPattern(String)}. Combinations
  * not shown in the table are illegal. A <i>SubformatPattern</i> must
  * be a valid pattern string for the {@code Format} subclass used.
+ * @implNote In the reference implementation, the limit of {@code ArgumentIndex} is 10,000.