org.tiogasolutions.dev.common.ReflectUtils Maven / Gradle / Ivy
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/*
* Copyright 2012 Jacob D Parr
*
* 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.tiogasolutions.dev.common;
import org.tiogasolutions.dev.common.exceptions.ExceptionUtils;
import java.lang.annotation.Annotation;
import java.lang.reflect.*;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
public class ReflectUtils {
private ReflectUtils() {
int i = 2;
}
public static Field getField(Class type, final String name) {
while (type != null) {
Field[] fields = type.getDeclaredFields();
for (Field field : fields) {
if (name.equals(field.getName())) {
return field;
}
}
type = type.getSuperclass();
}
return null;
}
public static Object getFieldValue(final Object entity, final Field field) {
ExceptionUtils.assertNotNull(entity, "entity");
ExceptionUtils.assertNotNull(field, "field");
if (entity == null) {
return null;
}
try {
field.setAccessible(true);
return field.get(entity);
} catch (Exception ex) {
// I don't want to have to code to this.
throw new RuntimeException("Exception reflecting field's value", ex);
}
}
/**
* Uses the specified entity, field and value to identify a traditional setter method. If
* one cannot be used, then setFieldValue(..) will be used instead.
* @param entity The entity containing the field.
* @param field The field to update
* @param value The value to set the field to
*/
public static void setPropertyValue(final Object entity, final Field field, Object value) {
ExceptionUtils.assertNotNull(field, "field");
Method setter = ReflectUtils.getWriteMethod(field.getDeclaringClass(), field.getName(), field.getType());
if (setter == null) {
setFieldValue(entity, field, value);
return;
}
try {
setter.setAccessible(true);
setter.invoke(entity, value);
} catch (Exception ex) {
// I don't want to have to code to this.
throw new RuntimeException("Exception reflecting field's value", ex);
}
}
public static void setFieldValue(final Object entity, final Field field, Object value) {
ExceptionUtils.assertNotNull(field, "field");
try {
field.setAccessible(true);
field.set(entity, value);
} catch (Exception ex) {
// I don't want to have to code to this.
throw new RuntimeException("Exception reflecting field's value", ex);
}
}
public static Method getMethod(Class type, String methodName, Class...parameterTypes) {
try {
return type.getMethod(methodName, parameterTypes);
} catch (NoSuchMethodException e) {
// not found, keep trying
}
return null;
}
public static Method getWriteMethod(Class type, String propertyName, Class argType) {
String methodName = "set" + propertyName.substring(0,1).toUpperCase()+propertyName.substring(1);
try {
return type.getMethod(methodName, argType);
} catch (NoSuchMethodException e) {/* not found, keep trying */}
return null;
}
public static Method getReadMethod(Class type, String propertyName) {
String[] prefixes = {"get", "is", "was", "has"};
for (String prefix : prefixes) {
String methodName = prefix + propertyName.substring(0,1).toUpperCase()+propertyName.substring(1);
try {
return type.getMethod(methodName);
} catch (NoSuchMethodException e) {/* not found, keep trying */}
}
return null;
}
/**
* @param object the object for which a name is desired.
* @return the simple class name of the object, correctly dealing with null.
*/
public static String getName(Object object) {
return (object == null) ? null : object.getClass().getSimpleName();
}
/**
* @param offset the offset into the stack trace.
* @return the qualified name of the current method.
*/
public static String getQualifiedMethodName(int offset) {
StackTraceElement[] elements = Thread.currentThread().getStackTrace();
StackTraceElement element = elements[offset + 2];
return element.getClassName()+"."+element.getMethodName();
}
/**
* @param offset the offset into the stack trace.
* @return the name of the current method.
*/
public static String getMethodName(int offset) {
return getElement(offset+1).getMethodName();
}
public static String getClassName(int offset) {
return getElement(offset+1).getClassName();
}
public static StackTraceElement getElement(int offset) {
StackTraceElement[] elements = Thread.currentThread().getStackTrace();
return elements[offset + 2];
}
@SuppressWarnings("unchecked")
public static T[] newArray(Class type, int size) {
return (T[]) Array.newInstance(type, size);
}
public static T[] toArray(Class type, Collection collection) {
// noinspection unchecked
T[] array = newArray(type, collection.size());
int i = 0;
for (T t : collection) {
array[i] = t;
i++;
}
return array;
}
public static T getValueOf(Class type, String stringValue) {
try {
if (stringValue == null) {
return null;
}
String methodName = "valueOf";
Method method = ReflectUtils.getMethod(type, methodName, String.class);
if (method == null) {
String msg = String.format("The method %s.%s does not exist.", type.getName(), "valueOf");
throw new IllegalArgumentException(msg);
}
return invokeStatic(method, type, stringValue);
} catch (Throwable e) {
throw new RuntimeException(e);
}
}
public static List getFields(Class type) {
List fields = new ArrayList<>();
while (type != null) {
Collections.addAll(fields, type.getDeclaredFields());
type = type.getSuperclass();
}
return fields;
}
public static List getNonStaticFields(Class type) {
List fields = new ArrayList<>();
while (type != null) {
for (Field field : type.getDeclaredFields()) {
if (Modifier.isStatic(field.getModifiers()) == false) {
fields.add(field);
}
}
type = type.getSuperclass();
}
return fields;
}
public static List getStaticFields(Class type) {
List fields = new ArrayList<>();
while (type != null) {
for (Field field : type.getDeclaredFields()) {
if (Modifier.isStatic(field.getModifiers())) {
fields.add(field);
}
}
type = type.getSuperclass();
}
return fields;
}
public static Field getAnnotatedField(Object entity, Class annotation) {
for (Field field : getFields(entity.getClass())) {
if (field.isAnnotationPresent(annotation)) {
return field;
}
}
return null;
}
public static T invokeStatic(Method method, Class returnType, Object...args) throws InvocationTargetException, IllegalAccessException {
return invoke(null, method, returnType, args);
}
@SuppressWarnings("unchecked")
public static T invoke(Object object, Method method, Class returnType, Object...args) throws InvocationTargetException, IllegalAccessException {
if (returnType != null && method.getReturnType().equals(returnType) == false) {
String msg = String.format("The method \"%s.%s(..):%s\" does not return %s.",
method.getDeclaringClass().getName(),
method.getName(),
method.getReturnType().getName(),
returnType.getName());
throw new IllegalArgumentException(msg);
}
return (T)method.invoke(object, args);
}
}