Java Language Command line Argument Processing Argument processing using GWT ToolBase
Example
If you want to parse more complex command-line arguments, e.g. with optional parameters, than the best is to use google's GWT approach. All classes are public available at:
https://gwt.googlesource.com/gwt/+/2.8.0-beta1/dev/core/src/com/google/gwt/util/tools/ToolBase.java
An example for handling the command-line myprogram -dir "~/Documents" -port 8888 is:
public class MyProgramHandler extends ToolBase {
protected File dir;
protected int port;
// getters for dir and port
...
public MyProgramHandler() {
this.registerHandler(new ArgHandlerDir() {
@Override
public void setDir(File dir) {
this.dir = dir;
}
});
this.registerHandler(new ArgHandlerInt() {
@Override
public String[] getTagArgs() {
return new String[]{"port"};
}
@Override
public void setInt(int value) {
this.port = value;
}
});
}
public static void main(String[] args) {
MyProgramHandler myShell = new MyProgramHandler();
if (myShell.processArgs(args)) {
// main program operation
System.out.println(String.format("port: %d; dir: %s",
myShell.getPort(), myShell.getDir()));
}
System.exit(1);
}
}
ArgHandler also has a method isRequired() which can be overwritten to say that the command-line argument is required (default return is false so that the argument is optional.
