Corrected OObjectMethodFilter

OObjectMethodFilter.java

/*
 *
 * Copyright 2012 Luca Molino (molino.luca--AT--gmail.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.orientechnologies.orient.object.enhancement;

import com.orientechnologies.common.log.OLogManager;
import javassist.util.proxy.MethodFilter;

import java.lang.annotation.Annotation;
import java.lang.reflect.Field;
import java.lang.reflect.Method;

/**
 * @author luca.molino
 */
public class OObjectMethodFilter implements MethodFilter {

    public boolean isHandled(final Method m) {
        final String methodName = m.getName();
        final String fieldName = getFieldName(m);

        if (fieldName == null)
            return false;

        try {
            if (!OObjectEntitySerializer.isClassField(m.getDeclaringClass(), fieldName))
                return false;
            return (isSetterMethod(methodName, m) || isGetterMethod(methodName, m));
        } catch (NoSuchFieldException nsfe) {
            OLogManager.instance().warn(this, "Error handling the method %s in class %s", nsfe, m.getName(),
                    m.getDeclaringClass().getName());
            return false;
        } catch (SecurityException se) {
            OLogManager.instance().warn(this, "", se, m.getName(), m.getDeclaringClass().getName());
            return false;
        }
    }

    public String getFieldName(final Method m) {
        final String methodName = m.getName();
        final Class<?> clz = m.getDeclaringClass();

        if (methodName.startsWith("get"))
            return getFieldName(methodName, "get");
        else if (methodName.startsWith("set"))
            return getFieldName(methodName, "set");
        else if (methodName.startsWith("is"))
            return getFieldName(methodName, "is");
        else if (isScalaClass(clz)) {
            return getScalaFieldName(clz, methodName);
        }
        // NO FIELD
        return null;
    }

    protected String getFieldName(final String methodName, final String prefix) {
        final StringBuffer fieldName = new StringBuffer();
        fieldName.append(Character.toLowerCase(methodName.charAt(prefix.length())));
        fieldName.append(methodName.substring(prefix.length() + 1));
        return fieldName.toString();
    }

    public boolean isSetterMethod(final String fieldName, final Method m) throws SecurityException, NoSuchFieldException {
        Class<?> clz = m.getDeclaringClass();
        if (!fieldName.startsWith("set") || !checkIfFirstCharAfterPrefixIsUpperCase(fieldName, "set") || (isScalaClass(clz) && !fieldName.endsWith("_$eq")))
            return false;
        if (m.getParameterTypes() != null && m.getParameterTypes().length != 1)
            return false;
        return !OObjectEntitySerializer.isTransientField(m.getDeclaringClass(), getFieldName(m));
    }

    public boolean isGetterMethod(String fieldName, Method m) throws SecurityException, NoSuchFieldException {
        int prefixLength;
        Class<?> clz = m.getDeclaringClass();
        if (fieldName.startsWith("get") && checkIfFirstCharAfterPrefixIsUpperCase(fieldName, "get"))
            prefixLength = "get".length();
        else if (fieldName.startsWith("is") && checkIfFirstCharAfterPrefixIsUpperCase(fieldName, "is"))
            prefixLength = "is".length();
        else if (isScalaClass(clz) && fieldName.equals(getFieldName(m)))
            prefixLength = 0;
        else
            return false;
        if (m.getParameterTypes() != null && m.getParameterTypes().length > 0)
            return false;
        if (fieldName.length() <= prefixLength)
            return false;
        return !OObjectEntitySerializer.isTransientField(m.getDeclaringClass(), getFieldName(m));
    }

    private boolean checkIfFirstCharAfterPrefixIsUpperCase(String methodName, String prefix) {
        return methodName.length() > prefix.length() ? Character.isUpperCase(methodName.charAt(prefix.length())) : false;
    }

    protected boolean isScalaClass(Class<?> clz) {
        Annotation[] annotations = clz.getDeclaredAnnotations();
        for (Annotation a : annotations) {
            if ("scala.reflect.ScalaSignature".contains(a.annotationType().getName()) || "scala.reflect.ScalaLongSignature".contains(a.getClass().getName())) {
                return true;
            }
        }
        return false;
    }

    protected String getScalaFieldName(Class<?> clz, String name) {
        Field[] fields = clz.getDeclaredFields();
        for (Field field : fields) {
            if (name.equals(field.getName() + "_$eq")) {
                return field.getName();
            } else if (name.equals(field.getName())) {
                return field.getName();
            }
        }
        return null;
    }
}