用于串行通信的带有 rxtx 组件的 Java 小程序

Java applet with rxtx components for serial communication(用于串行通信的带有 rxtx 组件的 Java 小程序)

问题描述

我正在尝试构建一个可以打开串行端口并与之通信的小程序.我使用 rxtxcomm.jar 进行串行通信.我构建了一个可以在 eclipese 环境中完美运行的小程序.我构建了 Jar 文件并对其进行了签名，但是在浏览器中运行时，控制台会显示以下内容:

I am trying to build an applet that can open a serial port and communicate with the same. I have used rxtxcomm.jar for the serial communications. I have an applet built that works in the eclipese environment perfectly. I built the Jar file and signed the same, but when run in the browser the console shows the foll:

java.lang.ExceptionInInitializerError thrown while loading gnu.io.RXTXCommDriver
Exception in thread "thread applet-zhas_xbeeComm.xtalk-1" java.lang.ExceptionInInitializerError
    at zhas_xbeeComm.Xconnect$1.run(Xconnect.java:46)
    at java.security.AccessController.doPrivileged(Native Method)
    at zhas_xbeeComm.Xconnect.connect(Xconnect.java:40)
    at zhas_xbeeComm.xtalk.init(xtalk.java:22)
    at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.security.AccessControlException: access denied (java.lang.RuntimePermission loadLibrary.rxtxSerial)
    at java.security.AccessControlContext.checkPermission(Unknown Source)
    at java.security.AccessController.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkPermission(Unknown Source)
    at java.lang.SecurityManager.checkLink(Unknown Source)
    at java.lang.Runtime.loadLibrary0(Unknown Source)
    at java.lang.System.loadLibrary(Unknown Source)
    at gnu.io.CommPortIdentifier.<clinit>(CommPortIdentifier.java:123)
    ... 6 more

我什至在 connect 和 open 函数周围使用了 doPrivileged 方法，但它不起作用！请帮忙！！这是小程序的代码片段:{/** 打开一个端口并开始读写的函数 */

I have even used doPrivileged method around the connect and open functions but it aint working! Please help!! Here is a snippet of the code of the applet: { /** Function to open a port and begin reading and writing */

public void connect ( final String portName ) throws Exception
{   

    AccessController.doPrivileged(new PrivilegedAction() {
    public Object run() {
        // privileged code goes here, for example:

        // 1. added try catch for no such port exception;
        try {
            portIdentifier = CommPortIdentifier.getPortIdentifier(portName); //line 46
            } catch (NoSuchPortException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            }

}

推荐答案

刚遇到同样的问题.请确保对 RXTX 库的第一次调用是在 doPrivileged 块中.如果它将尝试在特权块之前加载库 - 它将失败并出现此错误.

Just had the same problem. Please make sure that the first call to RXTX library is in doPrivileged block. If it will try to load library before privileged block - it will fail with this error.

一些附加信息:http://hacky.typepad.com/blog/2009/05/using-rxtxcomm-in-applets.html

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