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1 Chapter 1 : J2ME: The Complete Reference The J2ME_CLASSPATH option controls the class library produced by the build. The default is cdc. Again, the CVM_JAVABIN option sets the path to your JDK bin directory, and the CVM_GNU_TOOLS_PATH sets the path to the GNU tools. Results for the format string yyyy. Results for the format string MMMM. For example, in Figure 7, the time zone is shown as CET, Central European Time, which we requested by specifying a time zone parameter of "zzz". However, if we change the time zone parameter to "zzzz" to get the full-text version of the time zone, the output may no longer be what you expect, as shown in Figure 9. Eye on the clock CET is used only during winter months in Austria. Notice the code for the client side consists only of setting the request method to GET. No header or body information is necessary for this MIDlet. Simply looking at how the servlet is invoked gives us a hint that we will be using a GET request method, because all parameters are passed as part of the URL rather than being sent in a separate stream. In Listing 12 you can see how we pass a parameter with the name format from the client to the server. The servlet will extract the value of this parameter to determine how to format the requested date. Passing a format parameter http: The bulk of what we are after is inside the method dopost. We first store the format requested by the client in the variable format. Next, we call SimpleDateFormat to create an instance of our preferred date formatting object and follow this with a call to create a new Date object. The servlet code package corej2me; import javax. There is no header information, so we move directly to reading the server data from an input stream, storing the results in the variable servermsg. After a successful call to callservlet we append the saved string returned from the server onto the Form our primary user interface component, which in turn displays the results on the device, as shown in Listing This was followed by a discussion of HTTP support, including how to package a client request, as well as interpret a server response. To demonstrate the concepts presented up to this point, we wrote a file-viewer MIDlet that downloaded and displayed a text file. In the final section of this article we wrote a comprehensive MIDlet to access a Java servlet. This included a broad range of network communication operations, such as passing parameters to the servlet, interpreting and processing the parameters on the server side and, finally, retrieving and displaying the server response on the client. With the completion of this comprehensive overview, you now have a baseline of information to begin exploring and developing your own J2ME applications! Part 1 provides an introduction to the MIDP high-level interface. Part 2 details MIDP s low-level interface. Part 3 goes inside the Record Management System. If you are new to the Wireless Toolkit, " MIDlet development with the Wireless Toolkit " developerworks, March provides an excellent starting point for learning to use it. The KVM mailing list is an excellent resource for J2ME developers, offering a searchable archive and an active discussion area. Muchow is a comprehensive guide to J2ME development. You can also visit the Core J2ME Web site for additional articles, tutorials and developer resources. The WebSphere Micro Environment provides an end-to-end solution connecting cellular phones, PDAs, and other pervasive devices to e-business. The alphaworks Web Services Toolkit for Mobile Devices provides tools and a runtime environments for developing applications that use Web services on small mobile devices, gateway devices, and intelligent controllers. The developerworks Wireless zone offers a wealth of technical content on pervasive computing. Also see the Java technology zone tutorials page for a complete listing of free tutorials from developerworks. Page 1

2 Chapter 2 : J2ME: Hello World Mobile Application - CodeProject This tutorial will show you how to create a J2ME MIDP RSS Reader application with NetBeans With RSS Reader you can read RSS feeds with your mobile device. This application is designed to work with MIDP so it is also compatible with older devices. Creating new mobile application project with. You can skip this step by manually modifying the J2ME stubs that you already have Do this if you made any manual modifications to the generated stubs. The usage policy defines the allowed permission associated with the content to the end user with additional temporal and monetary constraints if necessary. The common types of permission include: The right to invoke the application for example, a J2ME game. The right to display the content for example, an image. The optional constraints on the permission for providing fine-grained consumption control of content for example, preview rights. The number of times the permission rights are granted for example, the number of times you can run. The recurring period of time during which the permission rights are granted for example, the number of hours you can use. Start and End time: The pre-defined time range which the permission rights are granted. There are many standards on expressing the digital rights. The duration is specified in years, months, days, hours or minutes or all of these. A standard conversion is used to handle years days and months 30 days. The policy creation and the association of the policy with content is similar in both cases. The actual packaging of the policy with the content occurs at download time. The policy is enforced on the downloaded content after the user launches the downloaded application on the device. The custom implementation of Digital Rights Policy or Content Enhancement is a two-step development process. This implementation is also referred to as a Digital Rights Object. DRMPackager interface, which implements the packaging logic of content with the Rights object developed in Step 1. It defines a constructor with a single argument of type Javax. MIDlet to satisfy the general contract of DRMAgent, The implementation of onstartapp method displays a splash screen by calling the showsplash method that houses the business logic of the policy. Finally, the event handler of splash screen calls resumestartapp for the packaged application to resume normally. The compiled and pre-verified class file or JAR file which must also be pre-verified containing the class file can be packaged by defining a packager as explained in Section The following class Example describes the packaging logic of the Rights object. Example Packaging logic of the Rights object package devguide; import oracle. This class implements the general contract of DRMPackager by implementing the following method. To create a new Digital Rights Policy: From the browsing page Figure, click Create. Enter the name of the package. Enter the Name of the policy. For more information on creating a MIDlet application, see Section 4. The uploaded J2ME application can then be published as an application using the Content Manager to users groups for downloading. The association of the content with a DRM policy is done at the service creation time. All Content download transactions are recorded in an audit table. The content repository stores the deliverable contents information for any uploaded content. The information is accessible through public APIs. Table describes this information. Table Deliverable Content. Page 2

3 Chapter 3 : News, Tips, and Advice for Technology Professionals - TechRepublic J2me Edit TextArea class Extend the TextArea Component in the lwuit library of J2me. The extended TextArea must behave like the TextArea class but the only difference is that it must allow the user to type in text in the same way that the user would type text into a TextField. After browsing though other blog posts about how to publish an Android Library I still found that there were some missing details and that all the information was in different places. So I am going to go through this process and show what worked for me. For starters, I use Android Studio, which uses Gradle as the official build system, to set up all my Android projects. Make sure to download the latest version of Android Studio. Terminology Before we begin there is some terminology to get familiar with. Project â A project in Android Studio represents a complete Android app. Android Studio projects consist of one or more modules. A project in Android Studio is like a workspace in Eclipse. Module â A module is a component of your app that you can build, test, or debug independently. Modules contain the source code and resources for your app. Maven Central Repository â A repository provided by the Maven community. It contains a large number of commonly used libraries. Search Maven to browse the content of the central maven repository. Gradle, Please is another tool that allows you to search Maven Central. Gradle uses the jcenter repo if you included jcenter into your repositories section Notes about jcenter. It is a hosted deployment of Sonatype Nexus Professional with the Nexus Staging Suite used for the deployment process and validation, combined with a sync process to the Central Repository content delivery network. There are a few modifications you need to make to your project so that it is ready to be published as a library to Maven Central. Separate the code that is core to the library and code that shows sample usage of the library. In my projects, I separate these out into two separate modules library and sample. Checkout out the tips on setting up a library module. You may need to rename your modules. Page 3

4 Chapter 4 : J2ME MIDP RSS Reader Tutorial for NetBeans This book is dedicated to Anne, Sandy, Joanne, Amber-Leigh Christine, and Graaf, without whose help and support this book couldn t be written. Complete Reference / J2ME: TCR / Keogh / Automatic compilation and building of complex projects provides additional acceleration by giving immediate feedback on code changes and project status. All of these features depend on correct configuration of the projects in your workspace. We continue development of the product catalog and order processing application by configuring the project dependencies required to build and run that code. Part of the configuration consists of including a JAR file for the Apache log4j logging utility and a shared library of components from the Apache Axis Web Services toolkit. This chapter does not describe configuration and use of a source code version control repository. It is now time to expand our development to include the other projects set up in Chapter 3, "Managing Your Projects. Correct configuration is essential for error-free compilation, execution, and full use of Eclipse features such as Content Assist. The dialog shown in Figure is opened. The same property editor dialog may be opened using another approach. This is true for any resource, not only for projects. Projects with a Java nature have property pages as shown in Figure Open this dialog by right-clicking on the com. Figure Configuring source folders in your Java project build path. Each Java project has its own build path that specifies all dependencies required to compile the project. Those dependencies may come from other Java projects in the workspace, from Java archive. The Java Build Path properties page contains four tabs: The source and output folders. If you initially create a project without separate source and output folders, you can change it here. Multiple source folders can be used in one project; e. Check-off other projects in the workspace whose output folders should be added to this build path. Location of other archive files required by this project. Order in which projects and libraries appear in the build path and the default runtime classpath; e. Your source folder must contain subfolders for the complete package hierarchy as used by your Java source files. As described in Chapter 2, "Hello Eclipse," you can create these folder hierarchies easily using the New Java Package wizard. All non-java files from the source folder are copied unchanged to the corresponding folder hierarchy in the output folder. These non-java files are usually properties files and resource files. This sometimes creates confusion when Eclipse users store other configuration or documentation files within their source folder tree and then are surprised to see them copied into the output folder. These other non-source files should be saved in regular project folders that are not configured as source folders in the configuration. Figure shows the source folder tab in the Java project properties. This project was created with separate source and output folders named src and bin, respectively. This setup will suffice for most new projects created within Eclipse, but you can change that configuration here. Click the Add Folder If you create a test folder without adding it as a configured source folder, then Java source files within it will not be compiled. This is especially true if you are building applications using Java runtime libraries other than the J2SE libraries. The most common reason for using multiple source folders is to accommodate preexisting source code that was created outside of Eclipse. Developers can be very creative when organizing their projects! A test folder is sometime embedded within the application source folder, or several logically separate source trees may be included in the same folder. Eclipse provides other ways to split these sources into logically separate projects or source folders without changing the original structure, which might be required by other tools or Ant build files. You can add inclusion and exclusion filters on a source folder to explicitly select the files that are or are not used to build this project. There are many other possibilities for configuring preexisting code within an Eclipse project. Search for "project configuration tutorial" in the Eclipse help documentation where other detailed scenarios and suggestions are provided. These dependencies are shown as a UML package diagram in Figure These package names are shortened versions of the fully qualified project names used in our workspace. They represent the import dependencies between top-level packages in our application, but not necessarily the dependencies of all sub-packages and external utility libraries. Figure Order processing application package dependencies. Click on the Projects tab in the build path configuration, as shown in Figure All of the projects in your current workspace are listed except for the project we are now Page 4

5 configuring, which is com. Figure Configuring project dependencies for com. Referring to the package diagram, we see that orders depends on catalog and ubl. Configure the dependencies in your Eclipse project by selecting the checkboxes for those two projects. The end result is that the output folders from these other two projects are included in the build path of the current project, and their classes are available while compiling classes for com. An archive file may be in a project within your current workspace or elsewhere on your file system. The library configuration for com. Figure Configuring libraries for com. The Libraries tab contains five buttons for specifying the location of required library files: Select archive files located within any project from the current workspace; projects are not required to be Java projects. Select archive files anywhere on your file system external to the current workspace. Use a Java classpath variable as the base path for external archives. Select from a list of user libraries that define collections of related archive files. Select any folder from a project in the current workspace that contains Java. An important consideration when planning your project configuration is portability between different developer workstations in a team environment, which might include portability across operating systems such as Windows, Linux, and Macintosh. The first library option, Add JARs, is usually the most portable but not always possible or desirable when using libraries from other vendor products. Using external libraries with absolute file paths is the least portable. It is common practice to create a subfolder named lib within a Java project that contains other JAR files required to build the project. If you copy the file into your project using the operating system command line or file explorer, then your Eclipse Navigator view or Package Explorer view is updated automatically if you have automatic refresh enabled; otherwise, you must manually refresh the lib folder see Chapter 3. Now click the Add JARs Expand the project and lib folder containing log4j. It should appear as in Figure If you expand the log4j. The folder or JAR file containing Java source code for classes in this library. This source attachment location is the same kind of entry we configured in Chapter 5, "Rapid Development," to enable Javadoc hover and Content Assist for the Java runtime library. If you have source code for other libraries, such as log4j, then edit this library entry to get the same benefits when working with its classes. You can also configure the Javadoc location for the Java runtime libraries by expanding the JRE System Library in this same configuration dialog. This location is preset with the value http: However, this will work only while you are connected to the Internet. You can change this URL to a local file path if you want to enable this feature while working offline. This approach to project configuration is the easiest way to ensure that library locations are portable between different developer workstations and operating systems. All libraries are stored within the project folders, and locations except for Javadoc files are relative to the workspace home. If you zip your workspace and send it to another developer, he or she can simply unzip and open it in his or her Eclipse workbench. All project building and Content Assist will work without change. Another way to configure library locations that also has benefits of machine and platform portability is to use classpath variables. Click the Add Variable In Chapter 3, we reviewed the benefits of linked resource locations for gaining developer and platform portability of project files located outside of the workspace. Classpath variables are very similar to linked resource locations but require separate definitions. Figure Extending a Java classpath variable in project build path. Click the Configure Variables Back in the dialog shown in Figure, select this variable and click the Extend Expand the common and lib folders and then select servlet-api. The Servlet library is now part of your project configuration. You can easily share this workspace or project with other developers who use a different path or different version of the Tomcat server. All other aspects of this project configuration remain unchanged. Change the order of class path entries in situations where the same class name exists in more than one project or JAR location. Choose which project or JAR entries are contributed to other projects that have this project as one of their dependencies. Figure Configuring order and export of libraries for com. The same class name may exist in more than one class path entry when you have a project in your workspace that includes an updated version of some classes in one of the referenced libraries. If you want to compile and run an application using the updated version, then you must place the project above the older library version in the build path order. Another approach is for the client project to import the library itself, in addition to importing the required project. Refer to the package diagram in Figure that shows dependencies between the projects in our order processing application. When configuring the build path for orders. Page 5

6 Chapter 5 : J2ME Development and Provisioning In a J2SE environment you can arrange for multiple applications to share a third-party library (an XML parser for instance), in the form of a JAR file or class files, simply by adding them to the CLASSPATH. In the J2ME realm, class sharing isn't as easy. The MIDlet model bars access to external. Native methods were enabled. The JVM was forced to run in interpreted only mode. As can be seen from above, all the implementations took roughly the same amount of real time to execute, except when the JVM was run in interpreted mode in which case it took much longer. Therefore, the MD5 implementation that ships with the JDK will be adequate in a large number of cases. On November 19, I reran the most important of the tests using Java build 1. A speed advantage still existed. Now that the native method has been added, the remaining optimizations that could be made to this package are no longer as dramatic as they used to be. If you try my optimized implementation and decide that you still need something even faster, try the following: Using a JIT should make a huge difference over a plain interpreter. Make sure the native method is being used. This will make a massive difference if you are stuck using a plain interpreter. Performance on Windows could probably be optimized some more to the point that it approaches the native md5sum. The speed of an existing MD5 implementation can be achieved very easily by simply calling Runtime. This would also not be as flexible as the native method solution because you would be limited to a single checksum at the end of each data stream whereas with the native method solution the checksum of all the data seen thus far can be calculated an arbitrary number of times at an arbitrary number of points in time. If the use of native methods is not a viable option, there might be additional speed improvements that can be attained from the Java-only version of the code. The author of the MD5 implementation at www. I suspect that the speed difference may not be substantial, and it is unlikely that it would outperform the optional native method, but it could be worth a try. As of this writing, his implementation was in the public domain, so it is could probably be assimilated without a licensing conflict. The Code This implementation has been derived from code originally written by Santeri Paavolainen and was retrieved from his website at http: The initial changes that I Tim Macinta made were heavy optimization of the code, some bug fixes, and I replaced Mr. I also moved the code into a Java package because it was originally distributed without its own package. I attempted to contact Mr. Paavolainen to see if he was interested in incorporating my changes into his distribution, but after about a week I had not heard back from him so I decided to make my changes available on my own website. Highlights of the distribution contents: Please see the documentation for this file for instructions on where in your path to place the native library and instructions for how to disable the search for the native library if you are running the code from within an applet or within any other context with a restrictive SecurityManager. Also contains some test code for computing the MD5 hash of a file see the main method. This is not a requirement of the license, it is just a friendly request. This helps me because it helps spread the word about my contract software development services. It helps you because the more interest my MD5 library receives, the more it will be improved. Also, the more interest it receives, the more I will be encouraged to release other libraries I have sitting around. Linking to this page is a free, easy way to show your support. Page 6

7 Chapter 6 : Fast MD5 Implementation in Java Whatever your experience level, J2ME: The Complete Reference is your essential one-stop resource for understanding and utilizing J2ME to build mobile applications and services. Understand the organization, configurations, and profiles of J2ME, including the new PIM API. This tutorial will cover these subjects: Creating new mobile application project with NetBeans 4. You can aquire source files here. You also need to download kxml mobile class library. The latest version of the library on time of writing was 2. You can download the latest kxml release here. Change the Project Location to any folder on your computer. Now the project node in Projects window should look like this: Repeat the previous actions and add icons package Now you have requred packages for the source code files and the application icons. Under Value, type your own name. Close the edit window by clicking OK button. Now we are going to add a reference to kxml library that you have downloaded on your computer. Browse to downloaded kxml2-min. Creating the source code files Now we are going to create the source code for this project. Now you should have downloaded the existing source code files, as mentioned in the requirements section. It could take a few second to refresh the packages content in the project window. Add an icon to your application Now we are going to add an icon to our Mobile application. The NetBeans IDE is smart enough to fill up all the fields as you only need to select the icon that you want your application to have. Close both windows by clicking the OK button. Press F11 to build your project. As the memory usage in smaller mobile devices is a critical issue, therefore the obfuscating is very important part of the mobile application development. The following screenshots have been taken from Sony Ericsson emulator. Chapter 7 : Configuring an Eclipse Java Project Java Build Path InformIT J2ME allows developers to use Java and the J2ME wireless toolkit to create applications and programs for wireless and mobile devices. This is the most comprehensive resource for Java developers seeking to understand and utilise J2ME when building mobile applications and services. Chapter 8 : McGraw-Hill Education Overview of J2ME. J2ME (Java 2, Micro Edition) is a technology for Java applications on small devices. As an application development platform, J2ME is standard-based and offers a rich UI, one that is comparable to browser-based solutions. Chapter 9 : J2ME, Part 4: The Generic Connection Framework Inc then launched the Java Community Program (JCP) that brought together corporate users, vendors, and technologists to develop a standard for enterprise Java APIs The result is the xv xvi J2ME: The Complete Reference Java 2 Platform Enterprise Edition, commonly referred to as Java 2 Enterprise Edition (J2EE), and the Java 2 Micro Edition (J2ME. Page 7