通过java的外部程序调用

我想通过Java运行NS2(这是一个外部程序在Linux)命令通过Java,使用ProcessBuilder时,我得到的ns命令未find错误

/home/maria/Documents/test.sh: line 4: ns: command not found Execution failed. org.apache.commons.exec.ExecuteException: Process exited with an error: 127 (Exit value: 127) at org.apache.commons.exec.DefaultExecutor.executeInternal(DefaultExecutor.java:404) at org.apache.commons.exec.DefaultExecutor.execute(DefaultExecutor.java:166) at org.apache.commons.exec.DefaultExecutor.execute(DefaultExecutor.java:153) at test.opencmd.runScript(opencmd.java:18) at test.opencmd.main(opencmd.java:30) 

我的java代码是

 package test; import java.io.*; public class test2 { public static void main(String args[]) { String s = null; try { // run the Unix "}; //System.out.print(System.getProperty("user.home")); Process p = Runtime.getRuntime().exec( "ns /home/maria/ns-allinone-2.35/ns-2.35/indep-utils/cmu-scen-gen && cbrgen.tcl -type cbr -nn 10 -seed 1 -mc 5 -rate 5.0"); BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream())); BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream())); // read the output from the command System.out.println("Here is the standard output of the command:\n"); while ((s = stdInput.readLine()) != null) { System.out.println(s); } // read any errors from the attempted command System.out.println("Here is the standard error of the command (if any):\n"); while ((s = stdError.readLine()) != null) { System.out.println(s); } System.exit(0); } catch (IOException e) { System.out.println("exception happened - here's what I know: "); e.printStackTrace(); System.exit(-1); } } } 

我想我不是正确的程序调用。

我猜jvm执行你的命令的终端/会话不知道'ns'在哪里/什么(即:你的可执行库)

尝试通过给你的图书馆的完整路径执行,如

 Process p = Runtime.getRuntime().exec( "/fullpath/ns /home/maria/ns-allinone-2.35/ns-.... 

Java无法找到'ns'。 要告诉Java程序,你必须提到完整的路径如下:

 Process p = Runtime.getRuntime().exec("/home/maria/ns-allinone-2.35/ns-2.35/indep-utils/cmu-scen-gen/setdest/setdest -v 2 -n 50 -p 2.0 -s 10.0 -t 200 -x 500 -y 500 -m 2 -M 15"); Process p = Runtime.getRuntime().exec("/home/maria/ns-allinone-2.35/bin/ns /home/maria/ns-allinone-2.35/ns-2.35/indep-utils/cmu-scen-gen/cbrgen.tcl -type cbr -nn 10 -seed 1 -mc 5 -rate 5.0"); 

如果NS是一个Java程序,那么使用java ns如下。

 Runtime.getRuntime().exec( "java ns /home/maria/ns-allinone-2.35/ns-2.35/indep-utils/cmu-scen-gen && cbrgen.tcl -type cbr -nn 10 -seed 1 -mc 5 -rate 5.0");