public static Method getMethod()

in ch-commons-util/src/main/java/com/cloudhopper/commons/util/ClassUtil.java [157:238]
49 lines of code
19 McCabe index (conditional complexity)

    public static Method getMethod(Class<?> type, String name, Class<?> returnType, Class<?> paramType, boolean caseSensitive)
        throws IllegalAccessException, NoSuchMethodException {
        
        // flag to help modify the exception to make it a little easier for debugging
        boolean methodNameFound = false;

        // start our search
        Class<?> classType = type;

        while (classType != null && !classType.equals(Object.class)) {

            for (Method m : classType.getDeclaredMethods()) {

                if ((!caseSensitive && m.getName().equalsIgnoreCase(name)) || (caseSensitive && m.getName().equals(name))) {

                    // we found the method name, but its possible the signature won't
                    // match below, we'll set this flag to help construct a better exception
                    // below
                    methodNameFound = true;

                    // should we validate the return type?
                    if (returnType != null) {
                        // if the return types don't match, then this must be invalid
                        // since the JVM doesn't allow the same return type
                        if (!m.getReturnType().equals(returnType)) {
                            throw new NoSuchMethodException("Method '" + name + "' was found in " + type.getSimpleName() + ".class"
                                    + ", but the returnType " + m.getReturnType().getSimpleName() + ".class did not match expected " + returnType.getSimpleName() + ".class");
                        }
                    // make sure the return type is VOID
                    } else {
                        if (!m.getReturnType().equals(void.class)) {
                            throw new NoSuchMethodException("Method '" + name + "' was found in " + type.getSimpleName() + ".class"
                                    + ", but the returnType " + m.getReturnType().getSimpleName() + ".class was expected to be void");
                        }
                    }

                    // return type was okay, check the parameters
                    Class<?>[] paramTypes = m.getParameterTypes();

                    // should we check the parameter type?
                    if (paramType != null) {
                        // must have exactly 1 parameter
                        if (paramTypes.length != 1) {
                            // this might not be the method we want, keep searching
                            continue;
                        } else {
                            // if the parameters don't match, keep searching
                            if (!paramTypes[0].equals(paramType)) {
                                continue;
                            }
                        }
                    // if paramType was null, then make sure no parameters are expected
                    } else {
                        if (paramTypes.length != 0) {
                            continue;
                        }
                    }

                    // if we got here, then everything matches so far
                    // now its time to check if the method is accessible
                    if (!Modifier.isPublic(m.getModifiers())) {
                        throw new IllegalAccessException("Method '" + name + "' was found in " + type.getSimpleName() + ".class "+
                                ", but its not accessible since its " + Modifier.toString(m.getModifiers()));
                    }

                    // everything was okay
                    return m;
                }
            }

            // move onto the superclass
            classType = classType.getSuperclass();
        }

        String signature = "public " + (returnType == null ? "void" : returnType.getName()) + " " + name + "(" + (paramType == null ? "" : paramType.getName()) + ")";
        
        if (methodNameFound) {
            throw new NoSuchMethodException("Method '" + signature + "' was found in " + type.getSimpleName() + ".class, but signature match failed");
        } else {
            throw new NoSuchMethodException("Method '" + signature + "' was not found in " + type.getSimpleName() + ".class");
        }
    }