Java tutorial
//package com.java2s; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; public class Main { public static void chmod(String filename, int permissions) { Class<?> fileUtils = null; try { fileUtils = Class.forName("android.os.FileUtils"); } catch (ClassNotFoundException e1) { e1.printStackTrace(); } Method setPermissions = null; int a; try { setPermissions = fileUtils.getMethod("setPermissions", new Class[] { String.class, int.class, int.class, int.class }); } catch (NoSuchMethodException e) { e.printStackTrace(); } try { a = (Integer) setPermissions.invoke(null, filename, permissions, -1, -1); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } } }