Java™ Application Development on Linux - Dator

120Chapter 5The Sun Microsystems Java Software <strong>Development</strong> Kit-deprecationThis causes every use or reference to a deprecated class or method to bedisplayed on compilation. 2-gPut full debugging information in the compiled class files. See also -g:(the next entry in this list).-g:keyword_listThis switch gives you fine-grained control over the amount of debug informationincluded in compiled class files. The argument after the colon maybe either none, in which case no debug information is included, or acomma-separated list with any combination of source, to include sourcefile debugging information, lines, to include line number information,or vars, to include information about local variable names. The default,if no -g flag of any kind is specified, is to include source file and linenumber information only.-nowarnDisables warning messages.-verboseCauses the compiler to output information about each class encounteredduring compilation. This can be helpful when trying to resolve problemswith missing class definitions.There are also a number of switches that relate to cross-compiling as wellas UNIX-specific options, but these are not commonly used. Refer to the SunJava SDK Tools documentation if you need details on these options.2. In Java, it is rare for APIs to break support for existing code. Rather than remove old methods,it is more common to deprecate them. This is done by putting a @deprecated tag in aJavadoc comment on the class or method. The Java compiler will issue a warning (if the-deprecated switch is on) whenever a deprecated class or method is used. In general, deprecationis a warning that the class or method will be removed in a future version of the codeor library. It is interesting to note that the javac compiler records that a method or class isdeprecated in the binary. Thus the compiler produces different output based on the contentsof a comment. As we have written simple compilers and interpreters, this creeps us out. Wehave always wondered why deprecated has not become a Java language keyword.