What is the / ** code used for in Java language?

To enter comments in the source code, in Java, you can use one of two ways:

// Comentário em uma única linha

/* Comentário
   que se divide em várias
   linhas
 */

When writing comments of the form (note the two asterisks on the first line)

/**
 *
 */

Comments can be interpreted by a tool - called Javadoc - which generates documentation based on the source code using, in addition to the comments between /** */ , other special annotations, such as @author and @date , which provide, respectively, authoring information and the creation date of the file. / p>

The wikipedia article gives you a good idea about Javadoc.

The Java API is an example of documentation generated using the tool.

Complementing some tags:

• {@ code} All text within the keys is not interpreted, including text with HTML markup and Java tags
• {@ docRoot} contains the root directory of the generated documentation
• @deprecated indicates that the file or method is deprecated, discontinued, therefore its use is not indicated
• @exception serves to indicate possible exceptions
• @throws is used to indicate possible releases
• {@ link} links to other documentation of some method
• @param is used to describe parameters
• {@ value} contains the value of a constant
• @version specifies the current version of the class or interface
• @since specifies the version where the method was included