CommPortIdentifier portID = CommPortIdentifier.getPortIdentifier("LPT1");
ParallelPort port = (ParallelPort) portID.open("Read", 30);
port.addEventListener(new ParallelPortEventListener() {
@Override
public void parallelEvent(ParallelPortEvent arg0) {
}
});
OutputStream out = port.getOutputStream();
这是我写的获得LPT端口的代码,下面的截图是设备管理器里面的所有端口
下面是控制台报错
gnu.io.NoSuchPortException
at gnu.io.CommPortIdentifier.getPortIdentifier(CommPortIdentifier.java:269)
at com.jayp.print.Test.service(Test.java:43)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:624)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
为什么一直显示没有这个端口,我初始化端口的配置哪里有问题吗?我是从网上找的一个demo写的
我用getPortIdentifiers()方法获取设备上的所有端口,但是得到的枚举类是空的,意思是这个设备上没有端口?但是这不可能啊。我是在本机上跑的servlet,然后做的端口映射远程在客户那里访问测试的,但是我在本地访问的这个枚举也是空,这到底是为什么?
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