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DI Container for LastaFlute, super forked from Seasar as Java8
There is a newer version: 2.0.0
/*
 * Copyright 2015-2021 the original author or authors.
 *
 * 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 org.lastaflute.di.util;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

import org.lastaflute.di.exception.IllegalAccessRuntimeException;
import org.lastaflute.di.exception.SIllegalArgumentException;
import org.lastaflute.di.util.tiger.LdiReflectionUtil;

/**
 * @author modified by jflute (originated in Seasar)
 */
public class LdiFieldUtil {

    protected static final String REFLECTION_UTIL_CLASS_NAME = LdiReflectionUtil.class.getName();
    protected static final Method GET_ELEMENT_TYPE_OF_COLLECTION_FROM_FIELD_TYPE_METHOD = getElementTypeFromFieldTypeMethod("Collection");
    protected static final Method GET_ELEMENT_TYPE_OF_LIST_FROM_FIELD_TYPE_METHOD = getElementTypeFromFieldTypeMethod("List");
    protected static final Method GET_ELEMENT_TYPE_OF_SET_FROM_FIELD_TYPE_METHOD = getElementTypeFromFieldTypeMethod("Set");

    protected LdiFieldUtil() {
    }

    public static Object get(Field field, Object target) throws IllegalAccessRuntimeException {
        assertArgumentNotNull("field", field);
        try {
            return field.get(target);
        } catch (IllegalAccessException ex) {
            throw new IllegalAccessRuntimeException(field.getDeclaringClass(), ex);
        }
    }

    public static int getInt(Field field) throws IllegalAccessRuntimeException {
        return getInt(field, null);
    }

    public static int getInt(Field field, Object target) throws IllegalAccessRuntimeException {
        try {
            return field.getInt(target);
        } catch (IllegalAccessException ex) {
            throw new IllegalAccessRuntimeException(field.getDeclaringClass(), ex);
        }
    }

    public static String getString(Field field) throws IllegalAccessRuntimeException {
        return getString(field, null);
    }

    public static String getString(Field field, Object target) throws IllegalAccessRuntimeException {
        try {
            return (String) field.get(target);
        } catch (IllegalAccessException ex) {
            throw new IllegalAccessRuntimeException(field.getDeclaringClass(), ex);
        }
    }

    public static void set(Field field, Object target, Object value) throws IllegalAccessRuntimeException {
        try {
            field.set(target, value);
        } catch (IllegalAccessException e) {
            throw new IllegalAccessRuntimeException(field.getDeclaringClass(), e);
        } catch (IllegalArgumentException e) {
            Class clazz = field.getDeclaringClass();
            Class fieldClass = field.getType();
            Class valueClass = value == null ? null : value.getClass();
            Class targetClass = target == null ? null : target.getClass();
            throw new SIllegalArgumentException("ESSR0094",
                    new Object[] { clazz.getName(), clazz.getClassLoader(), fieldClass.getName(), fieldClass.getClassLoader(),
                            field.getName(), valueClass == null ? null : valueClass.getName(),
                            valueClass == null ? null : valueClass.getClassLoader(), value,
                            targetClass == null ? null : targetClass.getName(), targetClass == null ? null : targetClass.getClassLoader() },
                    e);
        }
    }

    public static boolean isInstanceField(Field field) {
        int mod = field.getModifiers();
        // treat final fields as read-only property in lasta_di  
        //return !Modifier.isStatic(mod) && !Modifier.isFinal(mod);
        return !Modifier.isStatic(mod);
    }

    public static boolean isPublicField(Field field) {
        int mod = field.getModifiers();
        return Modifier.isPublic(mod);
    }

    public static Class getElementTypeOfCollectionFromFieldType(final Field field) {
        if (GET_ELEMENT_TYPE_OF_COLLECTION_FROM_FIELD_TYPE_METHOD == null) {
            return null;
        }
        return (Class) LdiMethodUtil.invoke(GET_ELEMENT_TYPE_OF_COLLECTION_FROM_FIELD_TYPE_METHOD, null, new Object[] { field });
    }

    public static Class getElementTypeOfListFromFieldType(final Field field) {
        if (GET_ELEMENT_TYPE_OF_LIST_FROM_FIELD_TYPE_METHOD == null) {
            return null;
        }
        return (Class) LdiMethodUtil.invoke(GET_ELEMENT_TYPE_OF_LIST_FROM_FIELD_TYPE_METHOD, null, new Object[] { field });
    }

    public static Class getElementTypeOfSetFromFieldType(final Field field) {
        if (GET_ELEMENT_TYPE_OF_SET_FROM_FIELD_TYPE_METHOD == null) {
            return null;
        }
        return (Class) LdiMethodUtil.invoke(GET_ELEMENT_TYPE_OF_SET_FROM_FIELD_TYPE_METHOD, null, new Object[] { field });
    }

    protected static Method getElementTypeFromFieldTypeMethod(final String type) {
        try {
            final Class reflectionUtilClass = Class.forName(REFLECTION_UTIL_CLASS_NAME);
            return reflectionUtilClass.getMethod("getElementTypeOf" + type + "FromFieldType", new Class[] { Field.class });
        } catch (final Throwable ignore) {}
        return null;
    }

    // ===================================================================================
    //                                                                       Assist Helper
    //                                                                       =============
    protected static void assertArgumentNotNull(String variableName, Object value) {
        if (variableName == null) {
            throw new IllegalArgumentException("The variableName should not be null.");
        }
        if (value == null) {
            throw new IllegalArgumentException("The argument '" + variableName + "' should not be null.");
        }
    }
}