[...]... to be the way ahead for Java on small devices, but, as noted at the beginning of this chapter, there are other Java platforms already in existence (and in use) that have similar scope The following sections briefly summarize these alternative platforms and compare them to J2ME 14 J2ME in a Nutshell 1. 3 .1 JavaCard JavaCard is a platform aimed at smart card technology Smart cards are the smallest environment.. .J2ME in a Nutshell Java Threads, by Scott Oaks and Henry Wong A book that describes how to make use of Java's built -in multithreading features, which are also available in the J2ME platform Learning Wireless Java, by Qusay Mahmoud An introduction to Wireless Java, this book also shows how to install MIDlets in some of the Java-enabled cell phones that are currently available J2ME Programming Resources... is based on JDK 1. 1.8 and includes a fully featured Java VM The specification, available at http://java.sun.com/products/personaljava/, designates each of the core JDK 1. 1.8 packages as required, modified, or optional Similar designations may also be applied to individual classes and methods A required package must contain all of the classes from its JDK 1. 1.8 counterpart, and each class must be a full... in a Nutshell Constant width Used in all Java code and generally for anything that you would type literally when programming, including keywords, data types, constants, method names, variables, class names, and interface names Constant width italic Used for the names of function arguments and generally as a placeholder to indicate an item that should be replaced with an actual value in your program... when they are loaded into the CLDC virtual machine during class file verification (see Section 2 .1. 2 for a discussion of class file verification) 2 .1. 1.2 Language omissions Aside from the floating point restrictions, there are a few other Java language features that are not available to CLDC applications: Reflection The java.lang.reflect package and all of the features of java.lang.Class that are connected... bestselling Java in a Nutshell, which is one of the two books that made it possible for me to make my living in the Java world First and foremost, therefore, I would like to express my thanks to David Flanagan, the author of Java in a 6 J2ME in a Nutshell Nutshell, both for his part in getting me started down this path and for his help and advice during the creation of reference material for J2ME in a Nutshell. .. explicitly state the contrary, everything I say also applies to any conforming virtual machine .1 The following sections describe the virtual machine and language features that are not supported in a CLDC environment or in which the CLDC behavior is different from that in J2SE 2 .1. 1 .1 Floating point support Since many of the processors used in the target platforms for CLDC do not have floating point hardware,... of smart cards You can find more information about JavaCard at http://java.sun.com/products/javacard/ 1. 3.2 EmbeddedJava EmbeddedJava is a JDK 1. 1-based platform that is used to create software for embedded devices These devices typically have a 32-bit processor with 512 KB of ROM and 512 KB of RAM available for the VM, class libraries, and embedded application Since embedded devices generally serve... for a much more general application environment than EmbeddedJava The target devices for Personal Java have up to 2 MB of ROM and at least 1 MB of RAM available for the Java platform itself, with more required for application software Some of the larger PDAs and communicator devices, such as the Compaq iPAQ and the Nokia 9 210 cell phone, are currently using the PersonalJava environment PersonalJava is... begin with an invocation of a constructor of its superclass (with the exception of the constructor of java.lang.Object) 20 J2ME in a Nutshell • Local variables and instance and static members declared to contain a reference to an object of a particular type must always hold a reference to an object of that type or one that is legally assignable to it It is not legal, for example, to define a variable . Graphics Clip 5.8 Rendering Text 5.9 Images 5 .10 Event Handling 5 .11 Multithreading and the User Interface 13 9 13 9 14 3 14 4 14 7 15 3 15 5 15 8 16 1 16 6 17 1 17 6 6. Wireless Java: Networking. Package Contents 308 308 309 310 11 . java.io Package java.io ByteArrayInputStream ByteArrayOutputStream DataInput DataInputStream DataOutput DataOutputStream EOFException InputStream. O'Reilly at http://java.oreilly.com/. Books that are of particular interest to J2ME programmers include: Java in a Nutshell, by David Flanagan A Java language tutorial and complete API