java - Java 小程序部署工具包 : how to avoid the redirect when no JVM is installed

Question

我创建了一个小程序；它是使用 Deployment Toolkit 部署的如下(网址是假的):

<script type="text/javascript" 
             src="https://www.java.com/js/deployJava.js"></script>
<script>
var attributes = {
        code:'br.com.brandizzi.adam.applet.MyApplet.class',
        archive:'http://adam.brandizzi.com.br/html/applet.jar',
        width : 50,
        height : 1
    };
    var parameters = {
        fontSize : 1,
    };
    var version = '1.6';
    deployJava.runApplet(attributes, parameters, version);
</script>

效果很好。然而，幸运的是，我通过一台没有 JVM 的机器访问了我的站点，它总是被重定向到 http://www.java.com。 - 作为 the documentation states :

If the client does not have the required minimum version of the JRE software, the Deployment Toolkit script redirects the browser to http://www.java.com to allow users to download the latest JRE software. On some platforms, users might be redirected before they can view the web page containing the applet.

有没有办法避免这种重定向？页面在没有 JVM 的情况下也能很好地工作，小程序只是一点点改进。无论如何，我们的用户可能会对这种重定向感到非常困惑，他们甚至没有安装 JVM 的权限。

Answer 1

如果你看一下 deployJava.js 脚本，runApplet 函数是这样的:

     /**
     * Ensures that an appropriate JRE is installed and then runs an applet.
     * minimumVersion is of the form #[.#[.#[_#]]], and is the minimum
     * JRE version necessary to run this applet.  minimumVersion is optional,
     * defaulting to the value "1.1" (which matches any JRE).
     * If an equal or greater JRE is detected, runApplet() will call
     * writeAppletTag(attributes, parameters) to output the applet tag,
     * otherwise it will call installJRE(minimumVersion + '+').

所以如果你这样打电话

deployJava.runApplet(attributes, parameters, null);

或者像这样

deployJava.runApplet(attributes, parameters, 'undefined');

或者像这样

deployJava.runApplet(attributes, parameters, '1.1');

它只会检查是否 完全 安装了 Java，然后才重定向到 java.com 进行安装。既然你有一个小程序，你就需要 Java :)

或者，您可以直接调用deployJava.writeAppletTag(attributes, parameters):

    /**
     * Outputs an applet tag with the specified attributes and parameters, where
     * both attributes and parameters are associative arrays.  Each key/value
     * pair in attributes becomes an attribute of the applet tag itself, while
     * key/value pairs in parameters become <PARAM> tags.  No version checking
     * or other special behaviors are performed; the tag is simply written to
     * the page using document.writeln().
     *
     * As document.writeln() is generally only safe to use while the page is
     * being rendered, you should never call this function after the page
     * has been completed.
     */