java的部署工具包脚本deployJava.js

jdksummer

原文地址：http://docs.oracle.com/javase/6/docs/technotes/guides/jweb/deployment_advice.html

Deployment Toolkit Script

To avoid browser compatibility issues, the Deployment Toolkit script provides JavaScript functions that automatically generate the HTML required to deploy RIAs. Developers should invoke these functions to deploy their solutions in a consistent fashion across various browsers.

The script exposes a single object, named deployJava, which contains the following public functions:

  • createWebStartLaunchButton(jnlp, minimumVersion) - Outputs a launch button for the specified JNLP URL. When clicked, the button will ensure that an appropriate JRE is installed and then launch the JNLP application.
  • createWebStartLaunchButtonEx(jnlp, minimumVersion) - Outputs a launch button for the specified JNLP URL. When clicked, the button will ensure that an appropriate JRE is installed and then launch the JNLP application. The JNLP file does not require a value for the codebase attribute. This function requires that the Java SE 6 update 18 release be present on the client. If the Java SE 6 update 18 release is not present on the client, then the user will be instructed to install the required software.
  • getBrowser() - Returns the name of the browser currently running.
  • getJREs() - Returns an array of currently-installed JRE version strings.
  • installJRE(requestVersion) - Triggers the installation of the specified requestVersion, the latest version matching the specified requestVersion, or the latest JRE. 
  • installLatestJRE() - Triggers the installation of the latest JRE 
  • isPlugin2() - Determines if the next generation Java Plug-in is the default.
  • isWebStartInstalled(minimumVersion) - Returns true if an installation of Java Web Start of the specified minimumVersion can be detected. 
  • launch- Launches JNLP application.
  • runApplet(attributes, parameters, minimumVersion) - Ensures that an appropriate JRE is installed and then runs an applet. 
  • setAdditionalPackages(packageList) - Sets additional package list to be used by kernel installer. 
  • setInstallerType(type) - Sets the preferred install type : null, online, kernel.
  • versionCheck(version) - Returns true if there is a matching JRE version currently installed (among those detected by the getJREs() function). 
  • writeAppletTag(attributes, parameters) - Outputs an applet tag with the specified attributes and parameters. The parameters argument is optional. 

See the human readable version of the Deployment Toolkit for a detailed description of these public functions. See the following Java Tutorial lessons for more information about deploying RIAs:

Deploying Java Plug-in Applets

In the old Java Plug-in, applets always run with the latest version of JRE installed on a client machine. The old Deployment Security Policy provides more information about this behavior.

With the next generation Java Plug-in introduced in the Java SE 6 update 10 release, you can specify that the Java kernel (core set of Java classes absolutely required by the JRE) or normal online installer be automatically downloaded, if the specified minimum JRE version is not already installed on the client. If the specified minimum JRE version does not exist, the latest version of the JRE is downloaded fromwww.java.com.

In the case of a Java kernel download, any additional packages may also be specified for download as required by the applet.

Using Applet Tag Attributes

Applets can be deployed via the applet tag. Parameters to configure deployment may be specified as attributes and parameters to the applet tag.

Use the runApplet() function in deployJava to ensure that a minimum Java Runtime Environment is available on a client machine before launching the applet.

<script src="http://www.java.com/js/deployJava.js"></script>
<script>
    var attributes = {codebase:\'http://java.sun.com/products/plugin/1.5.0/demos/jfc/Java2D\',
                      code:\'java2d.Java2DemoApplet.class\',
                      archive:\'Java2Demo.jar\',
                      width:710, height:540} ;
    var parameters = {fontSize:16} ;
    var version = \'1.6\' ;
    deployJava.runApplet(attributes, parameters, version);
</script>

The above code will launch the Java 2D applet on JRE version 1.6.0 or higher with one parameter (fontSize).

To trigger the installation of Java kernel and additional packages, add the following before the deployJava.runApplet() function:

   deployJava.setInstallerType(\'kernel\');
   // include any required packages as shown below
   deployJava.setAdditionalPackages(\'javax.swing, javax.xml\');

 

Using JNLP

To deploy applets using JNLP, specify the jnlp_href parameter in the applet tag as follows:

    
 <script src="http://www.java.com/js/deployJava.js"></script>
 <script> 
    var attributes = { code:\'java2d.Java2DemoApplet\',  width:710, height:540} ; 
    var parameters = {jnlp_href: \'java2d.jnlp\'} ; 
    deployJava.runApplet(attributes, parameters, \'1.6\'); 
 </script>

In this example, java2d.jnlp has the following deployment information

 <?xml version="1.0" encoding="UTF-8"?>
 <jnlp href="java2d.jnlp">
     <information>
       <title>Java2D Demo</title>
       <vendor>My Company, Inc.</vendor>
       <offline-allowed />
     </information>
     <resources>
       <j2se version="1.4+"
             href="http://java.sun.com/products/autodl/j2se" />
       <jar href="Java2Demo.jar" main="true" />
       <!-- Specify if using JNLP extensions
                                <extension name="SomeExtension"
                  href="http://some.server.com/some_extension.jnlp" />
                                -->
     </resources>
     <applet-desc 
         name="Java2D Demo"
         main-class="java2d.Java2DemoApplet"
         width="710"
         height="540">
     </applet-desc>
 </jnlp>


Using Applet Tag  Attributes and JNLP parameters:

To deploy an applet that runs on the old and new Java Plug-ins, specify the applet tag attributes and JNLP parameters as shown in the example below:

var attributes = {codebase:\'http://java.sun.com/products/plugin/1.5.0/demos/jfc/Java2D\',
                      code:\'java2d.Java2DemoApplet.class\', archive:\'Java2Demo.jar\', width:710, height:540} ; 
var parameters = {fontSize:16, jnlp_href:\'java2d.jnlp\'} ; 
var version = \'1.6\' ; 
deployJava.runApplet(attributes, parameters, version);

Determining final deployment information

The applet tag and JNLP file provide overlapping mechanisms to specify the same information. For example, width, height, code etc. may be specified both as attributes of the applet tag and in the JNLP file. The following rules are applied to various attributes in order to determine the final deployment information:

  • width and height: These attributes are always taken from the <applet> tag and not from the JNLP file. The assumption is that the browser knows best how big the applet should be on the web page, and only the browser can support page-relative width and height (for example, width="50%").
  • codebase: It is recommended that you either:
    • leave the jnlp tag\'s codebase attribute empty for both the main and extension JNLP file, allowing the referencing JNLP file or <applet> tag to implicitly specify the codebase, or
    • specify an absolute URL for the codebase of any main or extension JNLP file

    Refer to CodeBase Determination for further information.

  • code: The code attribute in the <applet> tag will be ignored.
  • Any applet parameters specified using the <param> tag are merged with those specified in the JNLP file. If the same parameter is specified via both the <applet> tag and the JNLP file, the <applet> tag\'s version overrides the JNLP file\'s version, except for the java_arguments and java_version parameters.
  • The new java_arguments and java_version parameters are unnecessary in JNLP applets. The mechanisms in the JNLP file for requesting a JRE version, or passing command-line arguments to the JVM, are used instead. Command-line arguments and JRE version requests from the JNLP file override those specified in the HTML for the applet.
  • It may be advantageous to specify certain parameters desired early on in the applet\'s startup process, such as image, boxbgcolor, etc. in the HTML instead of in the JNLP file, because these are available immediately upon loading the web page rather than requiring the JNLP file to be downloaded separately first.

 

Deploying Java Web Start Applications

A Java Web Start Application can be deployed simply by creating a JNLP file that describes only the title, vendor, java version, jar file(s), and main class of the application. Here is an example of a Java Web Start application\'s JNLP file:

<jnlp spec="0.2 1.0"
      codebase="http://java.sun.com/javase/technologies/desktop/javawebstart/apps"
      href="notepad.jnlp">
   <information> 
      <title>Notepad App</title> 
      <vendor>Sun Microsystems, Inc.</vendor>
      <homepage href="http://java.sun.com/javase/technologies/desktop/javawebstart/demos.html"/>
      <description>Notepad Demo Description</description>
      <description kind="short">Notepad Demo Short Description</description>
      <icon href="images/notepad.gif"/>
      <offline-allowed/> 
   </information> 
   <resources>
      <j2se version="1.3+" href="http://java.sun.com/products/autodl/j2se"/>
      <j2se version="1.3+"/>
      <jar href="notepad.jar" main="true" download="eager"/>
   </resources>
   <application-desc main-class="Notepad"/>
</jnlp>

The application can then be deployed simply by providing a link to the JNLP file on your web page:

<a href="http://java.sun.com/javase/technologies/desktop/javawebstart/apps/notepad.jnlp">Launch Notepad</a>

Many other elements can be added to the JNLP file to control the user experience, security, and update process of the application, or to take advantage of several other features of the Java Network Launching Protocol (JNLP).

Java Web Start can use its Auto-Download mechanism to download the version of the JRE that it requires to run an application, but if the application wants to use advanced features of JNLP and Java Web Start that were added to a particular version, you may want to ensure that at least that version is installed before launching Java Web Start.

Suppose an application wants to use the SingleInstance Service (introduced in 1.5.0). Instead of just specifying <jnlp spec="1.5.0" .../> and letting the application fail on systems where only 1.4.2 or earlier is installed, you can use the deployJava javascript to ensure that at least version 1.5.0 is installed before launching Java Web Start.

<script src="http://www.java.com/js/deployJava.js"></script>
<script>
        var url = "http://java.sun.com/javase/technologies/desktop/javawebstart/apps/notepad.jnlp";
    deployJava.createWebStartLaunchButton(url, \'1.6.0\');
</script>

For an application not having specific version requirements you can just use the function without supplying minimumVersion.

<script>
    var url = "http://java.sun.com/javase/technologies/desktop/javawebstart/apps/notepad.jnlp";
    deployJava.createWebStartLaunchButton(url);
</script>

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