好吧，神圣的永恒的废话。当我最初决定关闭 Java 控制台中的“下一代插件”选项以使我的小程序在 Firefox 中运行时，我无意中禁用了 JNLP。我只是通过“尝试一些东西......任何东西”的最后手段才发现这一点。重新打开后，jnlp在IE中完美运行。 Firefox 当然是我的 POS 需要使用的浏览器（因为有 jsprint 插件）...但它当然不起作用。它不会下载 JNLP 文件，如果是，则说明出现了问题。它只是挂着。没有显示任何内容，但我的服务器日志显示正在下载所有图像和 html。但不是 jnlp 或任何 jar 文件。所以要么关闭下一代插件就会出现安全问题，要么打开它就无法使用Firefox。我可以做些什么而无需更改策略文件吗？
FWIW，我会将其标记为解决方案，并在其他地方启动关于我最新问题的新线程。以下是让这该死的东西正常工作所需的一切的最新内容（Firefox 除外）：
首先，确保在 Windows 中设置 PATH 和 CLASSPATH 环境变量。路径应该是C:\Program Files (x86)\Java\jdk1.7.0_01\bin（如果你有不同的版本，请更改为你自己的jdk目录）。 CLASSPATH 应该位于您创建 Java 类的位置。我的是D:\Files\Java\Classes。如果不设置 PATH 变量，则无法从任何目录运行“java”、“javac”或“jarsigner”。你必须在jdk的bin目录中。为您的用户帐户创建这些变量...而不是系统（因为可能已经有像这样命名的环境变量）。
接下来，为了签署您的小程序，请创建您的密钥库：
keytool -genkey -dname "cn=My Company, ou=Whatever, o=My Company, c=CA" -alias mycompany -keystore "D:\Files\Java\Certificates\certfile" -storepass MY_PASSWORD -validity 180
查看在线教程，确保您了解每个参数的用途。
我制作的 .BAT 文件是为了从 .java 文件轻松创建必要的 .jar 文件并对其进行签名。只需创建快捷方式或运行 .bat 文件，而不必每次更改 .java 文件时都手动执行此操作
@echo off
set certificate_password=MY_PASSWORD
set certificate_alias=myalias
set package=mycompany
set class_file=PortWriter
rem class_path is where my .java file resides (...\java\Classes\mycompany\PortWriter.java)
set class_path=D:\Files\Java\Classes
set certificate_loc=D:\Files\Java\Certificates\certfile
rem final_loc is the assets folder where the .jar file will reside
set final_loc=D:\Files\Websites\pos\app\assets\java
cd "%class_path%"
rem Change to "D:" otherwise Windows won't *actually* change directories from C: to D:
D:
javac -Xlint:unchecked "%package%\%class_file%.java"
pause
jar cfm "%final_loc%\%class_file%.jar" "%package%\Mainfest.txt" "%package%\*.class"
pause
del "%package%\*.class"
jarsigner -keystore "%certificate_loc%" -storepass %certificate_password% "%final_loc%\%class_file%.jar" %certificate_alias%
pause
Mainfest.txt（确保“Main-Class”行后面有一个回车符。如果您想在 JNLP 中指定主类，则不需要此 Manifest.txt 文件。）：
主类：mycompany.PortWriter
Java 文件：
package mycompany;
import com.engidea.comm.CommPort;
import com.engidea.comm.CommPortIdentifier;
import com.engidea.comm.SerialPort;
import com.engidea.comm.SerialPortEvent;
import com.engidea.comm.SerialPortEventListener;
import com.engidea.win32jcom.WinjcomIdentifier;
import java.io.*;
import java.util.Iterator;
import java.util.List;
import java.applet.*;
import java.security.*;
/*
WinJcom is a native interface to serial ports in java.
Copyright 2007 by Damiano Bolla, [email protected] /cdn-cgi/l/email-protection
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This can be used with commercial products and you are not obliged
to share your work with anybody.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* Simple class that can list system ports and allow IO
*/
public class PortWriter extends Applet {
private CommPortIdentifier portIdentifier;
private SerialPort serport;
public static void main(String[] args) {}
public void init() {
System.out.println("Booting RS232 Java Applet...");
}
public void Sends(String port, String message) {
final String com_port = port;
final String send_message = message;
AccessController.doPrivileged(new PrivilegedAction<Object>() {
public Object run() {
try {
portIdentifier = new WinjcomIdentifier(0);
try {
selectComport(com_port);
new Thread(new PortReader()).start();
try {
System.out.println(com_port + ": " + send_message);
typeSendBytes(send_message);
} catch (Exception e) {
System.out.println("Couldn't send data to " + com_port);
}
} catch (IOException e) {
System.out.println("Couldn't connect to " + com_port);
}
} catch (Exception e) {
System.out.println(e);
}
return null;
}
});
}
private void typeSendBytes( String message ) {
try {
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
String aStr = "";
if (aStr != null) {
aStr = message + "\r\n";
// WARNING: be careful, you shoulod select the encoding !
// This will timeout if you have FLOW CONTROL and theline is stuck !
byte []buf = aStr.getBytes();
serport.write(buf,0,buf.length);
}
} catch ( Exception exc ) {
exc.printStackTrace();
}
}
private SerialPort openPort ( String portName ) throws IOException {
try {
CommPort aPort = portIdentifier.getCommPort(portName);
aPort.open();
return (SerialPort)aPort;
}
catch ( Exception exc ) {
//System.out.println("exc="+exc);
//exc.printStackTrace();
throw exc;
}
}
private void selectComport ( String portName ) throws IOException {
try {
serport = openPort(portName);
serport.setSerialPortParams(9600,8, SerialPort.STOPBITS_2, SerialPort.PARITY_NONE);
serport.enableReceiveTimeout(20000);
serport.setEventListener(new EventListener());
serport.notifyOnDSR(true);
serport.notifyOnCarrierDetect(true);
serport.notifyOnCTS(true);
} catch (IOException exc) {
//System.out.println("Exc="+exc);
//exc.printStackTrace();
throw exc;
}
}
private final class EventListener implements SerialPortEventListener
{
public void serialEvent(SerialPortEvent ev)
{
System.out.println("Got event="+ev);
}
}
private final class PortReader implements Runnable
{
public void run()
{
try
{
// This will timeout if nothing is received in the specified time.
byte []buff = new byte[1];
while ( serport.read(buff,0,buff.length) > 0 )
{
// NOTE: you should be checking the encoding !
System.out.print(new String(buff));
}
}
catch ( Exception exc )
{
exc.printStackTrace();
}
}
}
}
JNLP 文件：
<?xml version="1.0" encoding="utf-8"?>
<jnlp>
<information>
<title>RS232 Communication Applet</title>
<vendor>My Company</vendor>
<description>RS232 Applet for communicating with POS Display Pole</description>
<offline-allowed />
</information>
<security>
<all-permissions/>
</security>
<resources>
<j2se version="1.7.0+" />
<jar href="PortWriter.jar" part="com" main="true" />
<jar href="jcomport.jar" part="com" />
<nativelib href="winjcom.jar" part="com" />
</resources>
<applet-desc
name="RS232 Communication Applet"
main-class="mycompany.PortWriter"
width="1" height="1" />
</jnlp>
HTML:
<applet id="SerialPort" width="1" height="1" codebase="/assets/">
<param name="jnlp_href" value="PortWriter.jnlp">
</applet>
我已经获取了 winjcom.dll 文件并将其“jarred”并使用相同的证书文件对其进行了签名。我确保 cd 到 winjcom 所在的同一目录，以便它位于 .jar 文件的根目录中。我还获取了 winjcom 作者提供的 jcomport.jar 文件，并使用相同的 certfile 对其进行了重新签名。话虽这么说，所有 .jar 文件都已由同一证书文件签名。
我希望这可以帮助那些和我一样遇到麻烦的人。
