Java 运行时.exec()

Question

我可以毫无问题地从命令行运行这个命令(验证脚本执行):

c:/Python27/python ../feedvalidator/feedvalidator/src/demo.py https://das.dynalias.org:8080/das_core/das/2.16.840.1.113883.4.349/1012581676V377802/otherAdminData/careCoordinators 

如果我不使用 URL 参数并从 java 中执行以下操作:

String[] args1 = {"c:/Python27/python", "../feedvalidator/feedvalidator/src/demo.py" };
Runtime r = Runtime.getRuntime();
Process p = r.exec(args1);

它工作正常。如果我使用某些 URL 作为参数，例如:

String[] args1 = {"c:/Python27/python", "../feedvalidator/feedvalidator/src/demo.py" , "http://www.intertwingly.net/blog/index.atom"};
// or 
String[] args1 = {"c:/Python27/python", "../feedvalidator/feedvalidator/src/demo.py" , "http://www.cnn.com"};

它也可以正常工作。

但是如果我使用这个特定的 URL https://das.dynalias.org:8080/das_core/das/2.16.840.1.113883.4.349/1012581676V377802/otherAdminData/careCoordinators ，然后脚本就挂起(java 等待进程完成)。我不确定为什么它可以从该 URL 的命令行运行，但不能从 java 程序运行。我尝试在 URL 参数周围添加引号，但这也不起作用。我在 URL 中没有看到任何我认为需要转义的字符。

完整代码:

String urlToValidate = "https://das.dynalias.org:8080/das_core/das/2.16.840.1.113883.4.349/1012581676V377802/otherAdminData/careCoordinators";

String[] args1 = {"c:/Python27/python", "C:/Documents and Settings/vhaiswcaldej/DAS_Workspace/feedvalidator/feedvalidator/src/demo.py", urlToValidate };
System.out.println(args1[0] + " " + args1[1] + " " + args1[2]);

Runtime r = Runtime.getRuntime();
Process p = r.exec(args1);
BufferedReader br = new BufferedReader(new InputStreamReader(
p.getInputStream()));
int returnCode = p.waitFor();
 System.out.println("Python Script or OS Return Code: " + Integer.toString(returnCode));
if (returnCode >= 2) {
    .out.println("OS Error: Unable to Find File or other OS error.");
    }

String line = "";
while (br.ready()) {
     String str = br.readLine();
     System.out.println(str);
     if (str.startsWith("line")) {
     //TODO: Report this error back to test tool.
     //System.out.println("Error!");
     }
     }

Answer 1

你需要把进程的输出和错误流排干，否则当执行的程序产生输出时它会阻塞。

来自 Process documentation :

Because some native platforms only provide limited buffer size for standard input and output streams, failure to promptly write the input stream or read the output stream of the subprocess may cause the subprocess to block, and even deadlock.