java - Calling a simple shell script from java is not working

Question

My Shell script named "hello"

#This is a shell script
echo "Hello Shell World!"

My Java Code,

Runtime.getRuntime().exec(new String[]{"./hello"});

My Java code is executed with no errors, but I do not see "Hello Shell World!" being printed on the terminal.

I believe my script is being executed since I do not get errors like, "hello cannot be executed, there is no such file or directory".

I am executing this on a Linux machine, Ubuntu. Thanks!

Answer 1

当从 Java 运行外部程序时，输出不会到达（并且输入不会来自）Java 应用程序的终端。

外部程序（您的脚本）的输入和输出流（STDIN、STDOUT、STDERR）被定向到（从）InputStreams 和 OutputStreams，它们可以从您执行exec(...)

Answer 2

您应该使用阅读器来捕获命令的输出：

Process p=Runtime.getRuntime().exec(new String[]{"./hello"});
p.waitFor();
BufferedReader reader=new BufferedReader(new InputStreamReader(p.getInputStream()));
String line=reader.readLine();
while(line!=null) {
    System.out.println(line);
    line=reader.readLine();
}