Java Utililty Methods Method from Class

boolean existsMethod(final String clazz, final String name, final Class[] parameterTypes)
Analyze if a class or one of its super classes contains a given method.

Class c;
try {
 c = Class.forName(clazz);
} catch (ClassNotFoundException e) {
 return false;
return existsMethod(c, name, parameterTypes);

Method findMethod(Class javaClass, String methodName, Class[] methodParameterTypes)
Finding a method within a class potentially has to navigate through it's superclasses to eventually find the method.

try {
 return javaClass.getDeclaredMethod(methodName, methodParameterTypes);
} catch (NoSuchMethodException ex) {
 Class superclass = javaClass.getSuperclass();
 if (superclass == null) {
 throw ex;
 } else {
 try {
...

Method findMethod(Class c, String name, Class params[])
find Method

Method methods[] = findMethods(c);
if (methods == null)
 return null;
for (int i = 0; i < methods.length; i++) {
 if (methods[i].getName().equals(name)) {
 Class<?> methodParams[] = methods[i].getParameterTypes();
 if (methodParams == null)
 if (params == null || params.length == 0)
...

Method findMethod(Method m, Class c)
find Method

String name = m.getName();
Class<?> params[] = new Class<?>[0];
try {
 return c.getMethod(name, params);
} catch (Throwable th) {
 return null;

Method[] findMethods(Class c)
find Methods

Method methods[] = (Method[]) objectMethods.get(c);
if (methods != null)
 return methods;
methods = c.getMethods();
objectMethods.put(c, methods);
return methods;

Set getAllMethodsWithAnnotation(String packageName, Class annotation)
get All Methods With Annotation

Set<Method> methods = new HashSet<Method>();
try {
 for (Class<?> cls : getClasses(packageName)) {
 for (Method method : cls.getMethods()) {
 if (hasAnnotation(method, annotation)) {
 methods.add(method);
} catch (SecurityException e) {
 System.err.println("ClassUtil.getAllMethods: " + e.getMessage());
} catch (IOException e) {
 System.err.println("ClassUtil.getAllMethods: " + e.getMessage());
return methods;

Method getDeclaredMethod(final Class clazz, final String methodName, final Class[] methodParameterTypes)
Return a method on a given class with the given method name and parameter types.

return clazz.getDeclaredMethod(methodName, methodParameterTypes);

Method getMethod(Class type, Method m)
get Method

if (m == null || Modifier.isPublic(type.getModifiers())) {
 return m;
Class<?>[] inf = type.getInterfaces();
Method mp = null;
for (int i = 0; i < inf.length; i++) {
 try {
 mp = inf[i].getMethod(m.getName(), m.getParameterTypes());
...

Method getMethod(final Class javaClass, final String methodName, final Class[] methodParameterTypes, final boolean shouldSetAccessible)
Get a method declared in the given class.

Method method = findMethod(javaClass, methodName, methodParameterTypes);
if (shouldSetAccessible) {
 method.setAccessible(true);
return method;

Method[] getMethods(final Class clazz)
Get the list of methods in a class.

return clazz.getMethods();