1.18. Element `invoke`
Prev | 1. Reference | Next

### 1.18. Element `invoke`

    <invoke
      method = Qualified name of a Java static method
      arguments = string : ""
    />

Invokes specified Java™ static method, passing it specified string as an argument.

- The method generally belongs to a class which is contained in a `jar` dynamically discovered by XXE at startup time.

- The method must have one of the following signatures:

  - `method(java.lang.String arguments,
    java.io.File workingDir);`
  - `method(java.lang.String arguments,
    java.io.File workingDir,
    com.xmlmind.xmledit.util.Console console);`
  - `method(java.lang.String arguments,
    java.io.File workingDir,
    com.xmlmind.xmledit.util.Console console,
    com.xmlmind.xmledit.doc.Document docBeingEdited);`
  arguments

    The value of the `arguments` attribute after substituting all variables (`%0`, `%1`, `%D`, `%p`, `%C`, etc).

    All arguments, if any, are passed as a single string. That is, the method is responsible for properly parsing this string.

  workingDir

    The temporary directory created each time a process command is executed. Relative paths are generally relative to this directory.

  console

    A simple way to report information and non fatal errors to the user of the process command. Throw an exception to report a fatal error.

  docBeingEdited

    The document being edited.

- The method may return a value. If it returns a value, this value is converted to a `java.lang.String` using `toString()` and then returned by the `invoke` element (à la read, for use in a macro command for example).

- The method may throw any exception.

Examples:

    <invoke method="TestInvoke.echo"
            arguments="args={%*} doc='%D' pwd='%W' conf='%C'" />

    <invoke method="TestInvoke.echo2" />

    <invoke method="TestInvoke.gzip" arguments="__doc.xml" />

Static methods invoked by the above examples:

    public final class TestInvoke {
        public static void echo(String arguments, File workingDir,
                                Console console) {
            console.showMessage("arguments='" + arguments + "'", Console.INFO);
            console.showMessage("workingDir='" + workingDir + "'", Console.INFO);
        }

        public static void echo2(String arguments, File workingDir,
                                 Console console, Document docBeingEdited) {
            echo(arguments, workingDir, console);
            console.showMessage("docBeingEdited='" + docBeingEdited.getLocation()
                                + "'", Console.INFO);
        }

        public static File gzip(String arguments, File workingDir)
            throws IOException {
            File inFile = new File(workingDir, arguments.trim());
            if (!inFile.isFile())
                throw new FileNotFoundException(inFile.getPath());
            File outFile = new File(inFile.getPath() + ".gz");
            FileInputStream in = new FileInputStream(inFile);

            try {
                GZIPOutputStream out =
                    new GZIPOutputStream(new FileOutputStream(outFile));

                byte[] bytes = new byte[8192];
                int count;

                while ((count = in.read(bytes)) != -1)
                    out.write(bytes, 0, count);

                out.finish();
                out.close();
            } finally {
                in.close();
            }

            return outFile;
        }
    }

Prev | Up | Next
1.17. Element `shell` | Home | 1.19. Element `subProcess`