org.analogweb.util.ReflectionUtils Maven / Gradle / Ivy

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package org.analogweb.util;

import java.lang.annotation.Annotation;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;

import org.analogweb.InvocationMetadata;
import org.analogweb.util.logging.Log;
import org.analogweb.util.logging.Logs;

/**
 * @author snowgoose
 */
public final class ReflectionUtils {

    private static final Log log = Logs.getLog(ReflectionUtils.class);

    @SuppressWarnings("unchecked")
    public static  T getMethodParameterAnnotation(Method method, Class annotationClass,
            int parameterIndex) {
        Annotation[][] annotations = method.getParameterAnnotations();
        if (annotations.length > parameterIndex) {
            for (Annotation annotation : annotations[parameterIndex]) {
                if (annotation.annotationType().equals(annotationClass)) {
                    return (T) annotation;
                }
            }
        }
        return null;
    }

    public static  T getInstanceQuietly(Class clazz) {
        try {
            return clazz.newInstance();
        } catch (InstantiationException e) {
            log.log("TU000008", e, new Object[] { clazz });
        } catch (IllegalAccessException e) {
            log.log("TU000008", e, new Object[] { clazz });
        }
        return null;
    }

    public static Object getInstanceQuietly(Constructor constructor, Object... args) {
        return getInstanceQuietly(Object.class, constructor, args);
    }

    @SuppressWarnings("unchecked")
    public static  T getInstanceQuietly(Class type, Constructor constructor, Object... args) {
        try {
            if (constructor == null) {
                return null;
            }
            return (T) constructor.newInstance(args);
        } catch (IllegalArgumentException e) {
            log.log("TU000008", e, new Object[] { constructor.getDeclaringClass() });
        } catch (InstantiationException e) {
            log.log("TU000008", e, new Object[] { constructor.getDeclaringClass() });
        } catch (IllegalAccessException e) {
            log.log("TU000008", e, new Object[] { constructor.getDeclaringClass() });
        } catch (InvocationTargetException e) {
            log.log("TU000008", e, new Object[] { constructor.getDeclaringClass() });
        }
        return null;
    }

    public static  List> filterClassAsImplementsInterface(Class filteringType,
            Collection> collectedClasses) {
        return filterClassAsImplementsInterface(filteringType, collectedClasses, ASSIGNABLE_FROM_FILTER);
    }

    public static  List> filterClassAsImplementsInterface(Class filteringType,
            Collection> collectedClasses, TypeFilter typeFilter) {
        List> implementsTypes = new ArrayList>();
        for (Class clazz : collectedClasses) {
            Class filterResult = typeFilter.filterType(clazz, filteringType);
            if (filterResult != null) {
                implementsTypes.add(filterResult);
            }
        }
        return implementsTypes;
    }

    public static Method[] getMethods(Class clazz) {
        return clazz.getMethods();
    }

    public interface TypeFilter {

         Class filterType(Class actualClass, Class filteringType);
    }

    private static final TypeFilter ASSIGNABLE_FROM_FILTER = new TypeFilter() {

        @Override
        @SuppressWarnings("unchecked")
        public  Class filterType(Class actualClass, Class filteringType) {
            if (filteringType.isAssignableFrom(actualClass)) {
                return (Class) actualClass;
            } else {
                return null;
            }
        }
    };

    public static void writeValueToField(Field field, Object instance, Object value) {
        if (field == null) {
            return;
        }
        try {
            setAccessible(field);
            field.set(instance, value);
        } catch (IllegalAccessException e) {
            // swallow
            log.log("TU000009", e, field);
        }
    }

    public static void writeValueToField(String fieldName, Object instance, Object value) {
        Field field = getAccessibleField(instance.getClass(), fieldName);
        if (field == null) {
            return;
        }
        try {
            field.set(instance, value);
        } catch (IllegalAccessException e) {
            // swallow
            log.log("TU000009", e, field);
        }
    }

    public static Field getAccessibleField(final Class targetClass, final String fieldName) {
        Field field;
        try {
            field = targetClass.getDeclaredField(fieldName);
            if (Modifier.isPublic(field.getModifiers()) == false) {
                setAccessible(field);
            }
            return field;
        } catch (SecurityException e) {
            return null;
        } catch (NoSuchFieldException e) {
            return null;
        }
    }

    public static void setAccessible(final Field field) {
        AccessController.doPrivileged(new PrivilegedAction() {

            @Override
            public Field run() {
                try {
                    if (Modifier.isPublic(field.getModifiers()) == false && !field.isAccessible()) {
                        field.setAccessible(true);
                    }
                    return field;
                } catch (SecurityException e) {
                    // ignore.
                    return null;
                }
            }
        });
    }

    public static Object getValueOfField(final String fieldName, final int modifier, final Object instance) {
        return AccessController.doPrivileged(new PrivilegedAction