Merge tag 'v2.3.28' into testing

[lgpl/argeo-commons.git] / org.argeo.cms / src / org / argeo / api / cli / DescribedCommand.java

diff --git a/org.argeo.cms/src/org/argeo/api/cli/DescribedCommand.java b/org.argeo.cms/src/org/argeo/api/cli/DescribedCommand.java
new file mode 100644 (file)
index 0000000..51cb2ce
--- /dev/null
+++ b/org.argeo.cms/src/org/argeo/api/cli/DescribedCommand.java
@@ -0,0 +1,60 @@
+package org.argeo.api.cli;
+
+import java.io.StringWriter;
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Function;
+
+import org.apache.commons.cli.CommandLine;
+import org.apache.commons.cli.DefaultParser;
+import org.apache.commons.cli.Options;
+import org.apache.commons.cli.ParseException;
+
+/** A command that can be described. */
+public interface DescribedCommand<T> extends Function<List<String>, T> {
+       default Options getOptions() {
+               return new Options();
+       }
+
+       String getDescription();
+
+       default String getUsage() {
+               return null;
+       }
+
+       default String getExamples() {
+               return null;
+       }
+
+       default CommandLine toCommandLine(List<String> args) {
+               try {
+                       DefaultParser parser = new DefaultParser();
+                       return parser.parse(getOptions(), args.toArray(new String[args.size()]));
+               } catch (ParseException e) {
+                       throw new CommandArgsException(e);
+               }
+       }
+
+       /** In order to implement quickly a main method. */
+       public static void mainImpl(DescribedCommand<?> command, String[] args) {
+               try {
+                       Object output = command.apply(Arrays.asList(args));
+                       System.out.println(output);
+                       System.exit(0);
+               } catch (PrintHelpRequestException e) {
+                       StringWriter out = new StringWriter();
+                       HelpCommand.printHelp(command, out);
+                       System.out.println(out.toString());
+                       System.exit(1);
+               } catch (IllegalArgumentException e) {
+                       StringWriter out = new StringWriter();
+                       HelpCommand.printHelp(command, out);
+                       System.err.println(out.toString());
+                       System.exit(1);
+               } catch (Exception e) {
+                       e.printStackTrace();
+                       System.exit(1);
+               }
+       }
+
+}