de.intarsys.tools.reflect.ObjectTools Maven / Gradle / Ivy
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/*
* Copyright (c) 2007, intarsys consulting GmbH
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* - Neither the name of intarsys nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package de.intarsys.tools.reflect;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Collection;
import de.intarsys.tools.component.IInitializeable;
/**
* A tool class for convenient object related tasks.
*
* This tool contains some simple reflection implementations.
*
*/
public class ObjectTools {
private static final Object[] EMPTY_PARAMETERS = new Object[0];
private static final Class[] EMPTY_PARAMETERTYPES = new Class[0];
public static final String GET_PREFIX = "get"; //$NON-NLS-1$
public static final String IS_PREFIX = "is"; //$NON-NLS-1$
protected static Object basicGet(Object object, String name)
throws FieldException {
if (object instanceof IBasicAccessSupport) {
return ((IBasicAccessSupport) object).basicGetValue(name);
}
try {
Method method = findGetter(object, name);
return method.invoke(object, (Object[]) null);
} catch (Exception e) {
//
}
try {
Field field = object.getClass().getField(name);
return field.get(object);
} catch (Exception e) {
//
}
try {
Method method = object.getClass().getMethod(name, (Class[]) null);
return method.invoke(object, (Object[]) null);
} catch (Exception e) {
throw new FieldAccessException(name, e);
}
}
protected static Object basicInsert(Object object, String name, Object value)
throws FieldException {
try {
Method method = findInserter(object, name, value);
return method.invoke(object, value);
} catch (Exception e) {
//
}
Object tempValue = get(object, name);
if (tempValue instanceof Collection) {
if (((Collection) tempValue).add(value)) {
return value;
}
return null;
}
throw new IllegalAccessError("can't insert in " + name);
}
protected static Object basicInvoke(Object object, String name,
Object... values) throws MethodException {
if (object instanceof IBasicInvocationSupport) {
return ((IBasicInvocationSupport) object).basicInvoke(name, values);
}
Method method = findMethod(object, name, values);
try {
return method.invoke(object, values);
} catch (Exception e) {
throw new MethodInvocationException(name, e);
}
}
protected static Object basicRemove(Object object, String name, Object value)
throws FieldException {
try {
Method method = findRemover(object, name, value);
return method.invoke(object, value);
} catch (Exception e) {
//
}
Object tempValue = get(object, name);
if (tempValue instanceof Collection) {
if (((Collection) tempValue).remove(value)) {
return value;
}
return null;
}
throw new IllegalAccessError("can't remove from " + name);
}
protected static Object basicSet(Object object, String name, Object value)
throws FieldException {
if (object instanceof IBasicAccessSupport) {
return ((IBasicAccessSupport) object).basicSetValue(name, value);
}
try {
Method method = findSetter(object, name, value);
return method.invoke(object, value);
} catch (InvocationTargetException e) {
throw new FieldAccessException(name, e.getCause());
} catch (Exception e) {
//
}
try {
Field field = object.getClass().getField(name);
Object oldValue = field.get(object);
field.set(object, value);
return oldValue;
} catch (Exception e) {
throw new FieldAccessException(name, e);
}
}
protected static boolean checkCandidate(Method method, String methodName,
Class[] pClasses) {
if (!method.getName().equals(methodName)) {
return false;
}
Class[] mClasses = method.getParameterTypes();
return checkCandidateClasses(mClasses, pClasses);
}
protected static boolean checkCandidateClass(Class mClass, Class pClass) {
if (!mClass.isAssignableFrom(pClass)) {
return false;
}
return true;
}
protected static boolean checkCandidateClasses(Class[] mClasses,
Class[] pClasses) {
if (mClasses.length != pClasses.length) {
return false;
}
for (int i = 0; i < mClasses.length; i++) {
if (!checkCandidateClass(mClasses[i], pClasses[i])) {
return false;
}
}
return true;
}
/**
* Create a new instance of Class "class"
*
* @param clazz
* @param expectedClass
* @return The new instance
* @throws ObjectCreationException
*/
public static T createObject(Class clazz, Class expectedClass)
throws ObjectCreationException {
return createObject(clazz, expectedClass, EMPTY_PARAMETERTYPES,
EMPTY_PARAMETERS);
}
/**
* Create a new instance of Class "class"
*
* @param className
* @param expectedClass
* @param parameterTypes
* @param parameters
* @return The new instance
* @throws ObjectCreationException
*/
public static T createObject(Class clazz, Class expectedClass,
Class[] parameterTypes, Object[] parameters)
throws ObjectCreationException {
if (clazz == null) {
throw new ObjectCreationException("class missing"); //$NON-NLS-1$
}
try {
if (expectedClass != null && !expectedClass.isAssignableFrom(clazz)) {
throw new ObjectCreationException(
"class '" + clazz.getName() //$NON-NLS-1$
+ "' not compatible with expected type '" + expectedClass + "'"); //$NON-NLS-1$ //$NON-NLS-2$
}
T object;
if (parameters == EMPTY_PARAMETERS) {
object = (T) clazz.newInstance();
} else {
Constructor constructor = clazz.getConstructor(parameterTypes);
object = (T) constructor.newInstance(parameters);
}
if (object instanceof IInitializeable) {
((IInitializeable) object).initialize();
}
return object;
} catch (NoClassDefFoundError e) {
throw new ObjectCreationException("class '" + clazz.getName() //$NON-NLS-1$
+ "' can't be instantiated", e); //$NON-NLS-1$
} catch (InstantiationException e) {
throw new ObjectCreationException("class '" + clazz.getName() //$NON-NLS-1$
+ "' can't be instantiated", e); //$NON-NLS-1$
} catch (IllegalAccessException e) {
throw new ObjectCreationException("class '" + clazz.getName() //$NON-NLS-1$
+ "' can't be instantiated", e); //$NON-NLS-1$
} catch (SecurityException e) {
throw new ObjectCreationException("class '" + clazz.getName() //$NON-NLS-1$
+ "' can't be instantiated", e); //$NON-NLS-1$
} catch (NoSuchMethodException e) {
throw new ObjectCreationException("class '" + clazz.getName() //$NON-NLS-1$
+ "' can't be instantiated", e); //$NON-NLS-1$
} catch (IllegalArgumentException e) {
throw new ObjectCreationException("class '" + clazz.getName() //$NON-NLS-1$
+ "' can't be instantiated", e); //$NON-NLS-1$
} catch (InvocationTargetException e) {
throw new ObjectCreationException("class '" + clazz.getName() //$NON-NLS-1$
+ "' can't be instantiated", e); //$NON-NLS-1$
} catch (Exception e) {
throw new ObjectCreationException("class '" + clazz.getName() //$NON-NLS-1$
+ "' can't be instantiated", e); //$NON-NLS-1$
}
}
/**
* Create a new instance of Class "className" via "classLoader".
*
* @param className
* @param expectedClass
* @param classLoader
* @return The new instance
* @throws ObjectCreationException
*/
public static T createObject(String className, Class expectedClass,
ClassLoader classLoader) throws ObjectCreationException {
Class clazz = ClassTools.createClass(className, expectedClass,
classLoader);
return createObject(clazz, expectedClass);
}
protected static Method findAnyMethod(Class clazz, String name,
Class... classes) throws MethodException {
Method[] methods = clazz.getMethods();
for (int i = 0; i < methods.length; i++) {
Method method = methods[i];
if (!method.getName().equals(name)) {
continue;
}
boolean found = true;
Class[] parameterTypes = method.getParameterTypes();
for (int j = 0; j < parameterTypes.length; j++) {
Class parameterType = parameterTypes[j];
if (!parameterType.isAssignableFrom(classes[j])) {
found = false;
break;
}
}
if (found) {
return method;
}
}
throw new MethodNotFoundException(name);
}
public static Method findGetter(Object object, String name)
throws MethodException {
try {
String methodName = GET_PREFIX
+ Character.toUpperCase(name.charAt(0)) + name.substring(1);
return object.getClass().getMethod(methodName, (Class[]) null);
} catch (Exception e) {
//
}
String methodName = IS_PREFIX + Character.toUpperCase(name.charAt(0))
+ name.substring(1);
try {
return object.getClass().getMethod(methodName, (Class[]) null);
} catch (Exception e) {
throw new MethodNotFoundException(name);
}
}
public static Method findInserter(Object object, String attribute,
Object value) throws MethodException {
String methodName = "insert"
+ Character.toUpperCase(attribute.charAt(0))
+ attribute.substring(1);
return findMethod(object, methodName, new Object[] { value });
}
protected static Method findMatchingMethod(Class clazz, String name,
Class[] classes) throws MethodException {
Method[] methods = clazz.getMethods();
for (int i = 0; i < methods.length; i++) {
Method method = methods[i];
if (checkCandidate(method, name, classes)) {
// todo quick hack. lookup best match, not first.
return method;
}
}
try {
return clazz.getMethod(name, classes);
} catch (Exception e) {
throw new MethodNotFoundException(name);
}
}
public static Method findMethod(Object object, String methodName,
Object... parameters) throws MethodException {
Class clazz = object.getClass();
Class[] parameterClasses = new Class[parameters.length];
for (int i = 0; i < parameters.length; i++) {
parameterClasses[i] = parameters[i].getClass();
}
Method method = null;
try {
method = findSimpleMethod(clazz, methodName, parameterClasses);
} catch (Exception e) {
method = findAnyMethod(clazz, methodName, parameterClasses);
}
return method;
}
public static Method findRemover(Object object, String attribute,
Object value) throws MethodException {
String methodName = "remove"
+ Character.toUpperCase(attribute.charAt(0))
+ attribute.substring(1);
return findMethod(object, methodName, new Object[] { value });
}
public static Method findSetter(Object object, String attribute,
Object value) throws MethodException {
String methodName = "set" + Character.toUpperCase(attribute.charAt(0))
+ attribute.substring(1);
return findMethod(object, methodName, new Object[] { value });
}
protected static Method findSimpleMethod(Class clazz, String name,
Class... classes) throws MethodException {
try {
return clazz.getMethod(name, classes);
} catch (Exception e) {
throw new MethodNotFoundException(name);
}
}
/**
* Get the value for field name in object.
*
* @param object
* @param name
* @return the value for field name in object.
* @throws IllegalAccessException
* @throws InvocationTargetException
* @throws NoSuchFieldException
*/
static public Object get(Object object, String name) throws FieldException {
// fix array syntax
String tempExpr = name.replace('[', '.');
if (tempExpr != name) {
tempExpr = tempExpr.replace(']', ' ');
}
int pos = tempExpr.indexOf('.');
if (pos == -1) {
return basicGet(object, name);
} else {
String pathPrefix = tempExpr.substring(0, pos);
String pathTrail = tempExpr.substring(pos + 1);
Object result = basicGet(object, pathPrefix);
return get(result, pathTrail);
}
}
/**
* Insert value in the relation field name in
* object. The value that was really inserted is returned (if
* supported by the underlying object implementation). To be exact, the
* result of the insert method invoked is returned.
*
* @param object
* @param name
* @param value
* @return the result of the insert method invoked is returned.
* @throws IllegalAccessException
* @throws InvocationTargetException
* @throws NoSuchFieldException
*/
static public Object insert(Object object, String name, Object value)
throws FieldException {
// fix array syntax
String tempExpr = name.replace('[', '.');
if (tempExpr != name) {
tempExpr = tempExpr.replace(']', ' ');
}
int pos = tempExpr.indexOf('.');
if (pos == -1) {
return basicInsert(object, name, value);
} else {
String pathPrefix = tempExpr.substring(0, pos);
String pathTrail = tempExpr.substring(pos + 1);
Object result = basicGet(object, pathPrefix);
return insert(result, pathTrail, value);
}
}
/**
* Invoke method name in object. The result of the
* invocation is returned.
*
* @param object
* @param name
* @param values
* @return The result of the invocation is returned.
* @throws MethodException
*/
static public Object invoke(Object object, String name, Object... values)
throws MethodException {
// fix array syntax
String tempExpr = name.replace('[', '.');
if (tempExpr != name) {
tempExpr = tempExpr.replace(']', ' ');
}
int pos = tempExpr.indexOf('.');
if (pos == -1) {
return basicInvoke(object, name, values);
} else {
String pathPrefix = tempExpr.substring(0, pos);
String pathTrail = tempExpr.substring(pos + 1);
Object result;
try {
result = basicGet(object, pathPrefix);
} catch (FieldException e) {
throw new MethodInvocationException(name, e);
}
return invoke(result, pathTrail, values);
}
}
/**
* Remove value in the relation field name in
* object. The value that was removed is returned (if supported
* by the underlying object implementation). To be exact, the result of the
* remove method invoked is returned.
*
* @param object
* @param name
* @param value
* @return the result of the remove method invoked is returned.
* @throws IllegalAccessException
* @throws InvocationTargetException
* @throws NoSuchFieldException
*/
static public Object remove(Object object, String name, Object value)
throws FieldException {
// fix array syntax
String tempExpr = name.replace('[', '.');
if (tempExpr != name) {
tempExpr = tempExpr.replace(']', ' ');
}
int pos = tempExpr.indexOf('.');
if (pos == -1) {
return basicRemove(object, name, value);
} else {
String pathPrefix = tempExpr.substring(0, pos);
String pathTrail = tempExpr.substring(pos + 1);
Object result = basicGet(object, pathPrefix);
return remove(result, pathTrail, value);
}
}
/**
* Set field name in object to value.
* The old value is returned (if supported by the underlying object
* implementation). To be exact, the result of the setter method invoked is
* returned.
*
* @param object
* @param name
* @param value
* @return the result of the setter method invoked is returned.
* @throws IllegalAccessException
* @throws InvocationTargetException
* @throws NoSuchFieldException
*/
static public Object set(Object object, String name, Object value)
throws FieldException {
// fix array syntax
String tempExpr = name.replace('[', '.');
if (tempExpr != name) {
tempExpr = tempExpr.replace(']', ' ');
}
int pos = tempExpr.indexOf('.');
if (pos == -1) {
return basicSet(object, name, value);
} else {
String pathPrefix = tempExpr.substring(0, pos);
String pathTrail = tempExpr.substring(pos + 1);
Object result = basicGet(object, pathPrefix);
return set(result, pathTrail, value);
}
}
}