Author Description

The Java Virtual Machine is the software implementation of a "CPU" designed to run compiled Java code. This includes stand-alone Java applications, as well as "applets" that are downloaded and run in Web browsers such as the NetScape Navigator. This book is a comprehensive programming guide for the Java Virtual Machine (JVM). The book is divided into two sections: the first section includes information on the semantics and structure of the JVM; the second section is a reference of the JVM instructions, or "opcodes." This book is intended to give readers a strong overview and reference of the JVM so that they may create their own implementations of the JVM or write their own compilers that create Java object code. The programming guide includes numerous examples written in Java assembly language. A Java assembler is provided with the book, so the examples can all be compiled and executed. The reference section offers a complete description of the instruction set of the VM and the class file format, including a description of the byte-code verifier.Perhaps the most important reason for learning about the Java Virtual Machine is that it gives you additional tools for solving programming problems in Java. The Java architecture is very open -- it's easy to add programatic extensions to Java, once you have learned the basic rules of the Java Virtual Machine. And the Java Virtual Machine is portable, so you only have to write the extension once.So if you don't like how a particular feature of the Java language works, why not create an extension library that operates in the way you need it to? It's not as hard as you might think, and this book gives you all the details you need.For example, if your application has a lot of matrix manipulation code in it, you probably want to write the matrix equations using operators like *, +, / and -. But Java doesn't let you override these operators. The solution? Create a simple parser that compiles the matrix expressions into efficient