Digitally Signed java Applets. Understanding Signing and Verification (The Java™ Tutorials > Deployment > Packaging Programs in JAR Files) The Java™ platform enables you to digitally sign JAR files.
You digitally sign a file for the same reason you might sign a paper document with pen and ink -- to let readers know that you wrote the document, or at least that the document has your approval. When you sign a letter, for example, everyone who recognizes your signature can confirm that you wrote the letter. Similarly when you digitally sign a file, anyone who "recognizes" your digital signature knows that the file came from you. The process of "recognizing" electronic signatures is called verification. Signed Applet Tutorial. By Larry Siden Introduction While volunteering on a pro-bono project at Menlo Innovations my colleagues and I encountered a problem.
A team had developed a Java applet in which a user types in a URL and clicks a button. The applet then downloads the web page specified by the URL and extracts any links (i.e. <a href=" java.security.AccessControlException: access denied (java.net.SocketPermission www.google.com connect,resolve) Background Java virtual machines run applets under a different security regime than applications. The JVM's security policy is set by a the file $JAVA_HOME/jre/lib/security/java.policy. It's syntax is described by Default Policy Implementation and Policy File Syntax . When I create an applet and test it with Eclipse's VM, Eclipse creates a file named java.policy.applet in the project root directory. /* AUTOMATICALLY GENERATED ON Tue Apr 16 17:20:59 EDT 2002*/ /* DO NOT EDIT */ grant { permission java.security.AllPermission; }; Digital Certificates.
Bruce Eckel's MindView, Inc: Free Electronic Book: Thinking in Java, 3rd Edition. This page apparently has both "Thinking in Java" and "Thinking in C++" as being reader's choices for best book of 2002.
I don't know which readers, other than that they are Chinese. Subscribe to the free OOP Newsletter from Bruce Eckel Subscribing to the newsletter provides automatic notification when the book is revised and information about CD Roms and Java Seminars and workshops. As many of you have noticed, I am terribly swamped with email and am unable to answer programming questions. There are several people who have kindly offered to answer Java questions that you would normally send to me. Steps for installing source code on your machine: Signed Applet Tutorial. Invoking Applet Methods From JavaScript Code (The Java™ Tutorials > Deployment > Java Applets) Invoking JavaScript Code From an Applet (The Java™ Tutorials > Deployment > Java Applets)
Java applets can invoke JavaScript functions present in the same web page as the applet.
The LiveConnect Specification describes details about how JavaScript code communicates with Java code. The netscape.javascript.JSObject class enables Java applets to retrieve a reference to JavaScript objects and interact with the web page. The Data Summary applet described next invokes JavaScript code to retrieve information from the web page and writes a data summary back to the web page.
Assume you have a web page with a few JavaScript functions. The example AppletPage.html has JavaScript functions to retrieve age, address, and phone numbers. Next, consider an applet class called DataSummaryApplet. Invokes the JSObject's setMember method to set the userName variable to "John Doe".Retrieves the age, address, and phone numbers and builds a string containing a summary of this data.Invokes the writeSummary JavaScript function to write the summary back to the web page. ...
Creating a JAR File (The Java™ Tutorials > Deployment > Packaging Programs in JAR Files) The basic format of the command for creating a JAR file is: jar cf jar-file input-file(s) The options and arguments used in this command are: The c option indicates that you want to create a JAR file.The f option indicates that you want the output to go to a file rather than to stdout.jar-file is the name that you want the resulting JAR file to have.
You can use any filename for a JAR file. By convention, JAR filenames are given a .jar extension, though this is not required.The input-file(s) argument is a space-separated list of one or more files that you want to include in your JAR file. The c and f options can appear in either order, but there must not be any space between them. This command will generate a compressed JAR file and place it in the current directory. Note: The metadata in the JAR file, such as the entry names, comments, and contents of the manifest, must be encoded in UTF8. Developing an Applet (The Java™ Tutorials > Deployment > Java Applets) Recommended Version 7 Update 55 Select the file according to your operating system from the list below to get the latest Java for your computer.
By downloading Java you acknowledge that you have read and accepted the terms of the end user license agreement <p><span class="termhighlight">In order to optimize your experience and provide you with accurate messages, please enable javascript in your browser for the duration of your Java installation. </span></p> What is Java? Java allows you to play online games, chat with people around the world, calculate your mortgage interest, and view images in 3D, just to name a few. » What is Java FAQ» More information about Java Java software for your computer, or the Java Runtime Environment, is also referred to as the Java Runtime, Runtime Environment, Runtime, JRE, Java Virtual Machine, Virtual Machine, Java VM, JVM, VM, Java plug-in, Java plugin, Java add-on or Java download.