Java/Reflection/Modifier
Содержание
- 1 find an accessible method passed in
- 2 Gets a method and forces it to be accessible, even if it is not.
- 3 Is Accessible
- 4 Listing the Modifiers of a Class Object
- 5 Listing the Modifiers of a Member Object: Field, Constructor, and Method are all subclasses of Member.
- 6 Make field accessible, explicitly setting it accessible
- 7 Overriding Default Access
- 8 Return true if the integer argument includes the abstract modifier, false otherwise.
- 9 Return true if the integer argument includes the final modifier, false otherwise.
- 10 Return true if the integer argument includes the private modifier, false otherwise.
- 11 Return true if the integer argument includes the protected modifier,false otherwise.
- 12 Return true if the integer argument includes the public modifier, false otherwise
- 13 Return true if the integer argument includes the static modifier, false otherwise.
- 14 Set Accessibility
find an accessible method passed in
import java.util.Map;
import java.util.HashMap;
import java.util.Collection;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.HashSet;
import java.util.SortedSet;
import java.util.TreeSet;
import java.util.Queue;
import java.util.LinkedList;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.Arrays;
import java.util.concurrent.ConcurrentHashMap;
import java.lang.annotation.Annotation;
import java.lang.reflect.Method;
import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import static java.lang.reflect.Modifier.isPublic;
import java.beans.PropertyDescriptor;
import java.beans.BeanInfo;
import java.beans.Introspector;
import java.beans.IntrospectionException;
/**
* Common utilty methods that are useful when working with reflection.
*
* @author Tim Fennell
*/
public class ReflectUtil {
/** A cache of property descriptors by class and property name */
private static Map<Class<?>, Map<String, PropertyDescriptor>> propertyDescriptors =
new ConcurrentHashMap<Class<?>, Map<String, PropertyDescriptor>>();
/** Static helper class, shouldn"t be constructed. */
private ReflectUtil() {}
/**
* Holds a map of commonly used interface types (mostly collections) to a class that
* implements the interface and will, by default, be instantiated when an instance
* of the interface is needed.
*/
protected static final Map<Class<?>,Class<?>> interfaceImplementations = new HashMap<Class<?>,Class<?>>();
/**
* Holds a map of primitive type to the default value for that primitive type. Isn"t it
* odd that there"s no way to get this programmatically from the Class objects?
*/
protected static final Map<Class<?>,Object> primitiveDefaults = new HashMap<Class<?>,Object>();
static {
interfaceImplementations.put(Collection.class, ArrayList.class);
interfaceImplementations.put(List.class, ArrayList.class);
interfaceImplementations.put(Set.class, HashSet.class);
interfaceImplementations.put(SortedSet.class, TreeSet.class);
interfaceImplementations.put(Queue.class, LinkedList.class);
interfaceImplementations.put(Map.class, HashMap.class);
interfaceImplementations.put(SortedMap.class, TreeMap.class);
primitiveDefaults.put(Boolean.TYPE, false);
primitiveDefaults.put(Character.TYPE, "\0");
primitiveDefaults.put(Byte.TYPE, new Byte("0"));
primitiveDefaults.put(Short.TYPE, new Short("0"));
primitiveDefaults.put(Integer.TYPE, new Integer(0));
primitiveDefaults.put(Long.TYPE, new Long(0l));
primitiveDefaults.put(Float.TYPE, new Float(0f));
primitiveDefaults.put(Double.TYPE, new Double(0.0));
}
/**
* The set of method that annotation classes inherit, and should be avoided when
* toString()ing an annotation class.
*/
private static final Set<String> INHERITED_ANNOTATION_METHODS =
new HashSet(Arrays.asList("toString", "equals", "hashCode", "annotationType"));
/**
* Looks up the default implementing type for the supplied interface. This is done
* based on a static map of known common interface types and implementing classes.
*
* @param iface an interface for which an implementing class is needed
* @return a Class object representing the implementing type, or null if one is
* not found
*/
public static Class<?> getImplementingClass(Class<?> iface) {
return interfaceImplementations.get(iface);
}
/**
* Attempts to determine an implementing class for the interface provided and instantiate
* it using a default constructor.
*
* @param interfaceType an interface (or abstract class) to make an instance of
* @return an instance of the interface type supplied
* @throws InstantiationException if no implementation type has been configured
* @throws IllegalAccessException if thrown by the JVM during class instantiation
*/
@SuppressWarnings("unchecked")
public static <T> T getInterfaceInstance(Class<T> interfaceType)
throws InstantiationException, IllegalAccessException {
Class impl = getImplementingClass(interfaceType);
if (impl == null) {
throw new InstantiationException(
"Stripes needed to instantiate a property who"s declared type as an " +
"interface (which obviously cannot be instantiated. The interface is not " +
"one that Stripes is aware of, so no implementing class was known. The " +
"interface type was: "" + interfaceType.getName() + "". To fix this " +
"you"ll need to do one of three things. 1) Change the getter/setter methods " +
"to use a concrete type so that Stripes can instantiate it. 2) in the bean"s " +
"setContext() method pre-instantiate the property so Stripes doesn"t have to. " +
"3) Bug the Stripes author ;) If the interface is a JDK type it can easily be " +
"fixed. If not, if enough people ask, a generic way to handle the problem " +
"might get implemented.");
}
else {
return (T) impl.newInstance();
}
}
/**
* Utility method used to load a class. Any time that Stripes needs to load of find a
* class by name it uses this method. As a result any time the classloading strategy
* needs to change it can be done in one place! Currently uses
* {@code Thread.currentThread().getContextClassLoader().loadClass(String)}.
*
* @param name the fully qualified (binary) name of the class to find or load
* @return the Class object representing the class
* @throws ClassNotFoundException if the class cannot be loaded
*/
@SuppressWarnings("unchecked") // this allows us to assign without casting
public static Class findClass(String name) throws ClassNotFoundException {
return Thread.currentThread().getContextClassLoader().loadClass(name);
}
/**
* <p>A better (more concise) toString method for annotation types that yields a String
* that should look more like the actual usage of the annotation in a class. The String produced
* is similar to that produced by calling toString() on the annotation directly, with the
* following differences:</p>
*
* <ul>
* <li>Uses the classes simple name instead of it"s fully qualified name.</li>
* <li>Only outputs attributes that are set to non-default values.</li>
*
* <p>If, for some unforseen reason, an exception is thrown within this method it will be
* caught and the return value will be {@code ann.toString()}.
*
* @param ann the annotation to convert to a human readable String
* @return a human readable String form of the annotation and it"s attributes
*/
public static String toString(Annotation ann) {
try {
Class<? extends Annotation> type = ann.annotationType();
StringBuilder builder = new StringBuilder(128);
builder.append("@");
builder.append(type.getSimpleName());
boolean appendedAnyParameters = false;
Method[] methods = type.getMethods();
for (Method method : methods) {
if (!INHERITED_ANNOTATION_METHODS.contains(method.getName())) {
Object defaultValue = method.getDefaultValue();
Object actualValue = method.invoke(ann);
// If we have arrays, they have to be treated a little differently
Object[] defaultArray = null, actualArray = null;
if ( Object[].class.isAssignableFrom(method.getReturnType()) ) {
defaultArray = (Object[]) defaultValue;
actualArray = (Object[]) actualValue;
}
// Only print an attribute if it isn"t set to the default value
if ( (defaultArray != null && !Arrays.equals(defaultArray, actualArray)) ||
(defaultArray == null && !actualValue.equals(defaultValue)) ) {
if (appendedAnyParameters) {
builder.append(", ");
}
else {
builder.append("(");
}
builder.append(method.getName());
builder.append("=");
if (actualArray != null) {
builder.append( Arrays.toString(actualArray) );
}
else {
builder.append(actualValue);
}
appendedAnyParameters = true;
}
}
}
if (appendedAnyParameters) {
builder.append(")");
}
return builder.toString();
}
catch (Exception e) {
return ann.toString();
}
}
/**
* Fetches all methods of all access types from the supplied class and super
* classes. Methods that have been overridden in the inheritance hierarchy are
* only returned once, using the instance lowest down the hierarchy.
*
* @param clazz the class to inspect
* @return a collection of methods
*/
public static Collection<Method> getMethods(Class<?> clazz) {
Collection<Method> found = new ArrayList<Method>();
while (clazz != null) {
for (Method m1 : clazz.getDeclaredMethods()) {
boolean overridden = false;
for (Method m2 : found) {
if ( m2.getName().equals(m1.getName()) &&
Arrays.deepEquals(m1.getParameterTypes(), m2.getParameterTypes())) {
overridden = true;
break;
}
}
if (!overridden) found.add(m1);
}
clazz = clazz.getSuperclass();
}
return found;
}
/**
* Fetches all fields of all access types from the supplied class and super
* classes. Fieldss that have been overridden in the inheritance hierarchy are
* only returned once, using the instance lowest down the hierarchy.
*
* @param clazz the class to inspect
* @return a collection of fields
*/
public static Collection<Field> getFields(Class<?> clazz) {
Map<String,Field> fields = new HashMap<String, Field>();
while (clazz != null) {
for (Field field : clazz.getDeclaredFields()) {
if ( !fields.containsKey(field.getName()) ) {
fields.put(field.getName(), field);
}
}
clazz = clazz.getSuperclass();
}
return fields.values();
}
/**
* Fetches the property descriptor for the named property of the supplied class. To
* speed things up a cache is maintained of propertyName to PropertyDescriptor for
* each class used with this method. If there is no property with the specified name,
* returns null.
*
* @param clazz the class who"s properties to examine
* @param property the String name of the property to look for
* @return the PropertyDescriptor or null if none is found with a matching name
*/
public static PropertyDescriptor getPropertyDescriptor(Class<?> clazz, String property) {
Map<String,PropertyDescriptor> pds = propertyDescriptors.get(clazz);
if (pds == null) {
try {
BeanInfo info = Introspector.getBeanInfo(clazz);
PropertyDescriptor[] descriptors = info.getPropertyDescriptors();
pds = new HashMap<String, PropertyDescriptor>();
for (PropertyDescriptor descriptor : descriptors) {
pds.put(descriptor.getName(), descriptor);
}
propertyDescriptors.put(clazz, pds);
}
catch (IntrospectionException ie) {
throw new RuntimeException("Could not examine class "" + clazz.getName() +
"" using Introspector.getBeanInfo() to determine property information.", ie);
}
}
return pds.get(property);
}
/**
* <p>Attempts to find an accessible version of the method passed in, where accessible
* is defined as the method itself being public and the declaring class being public.
* Mostly useful as a workaround to the situation when
* {@link PropertyDescriptor#getReadMethod()} and/or
* {@link java.beans.PropertyDescriptor#getWriteMethod()} returns methods that are not
* accessible (usually due to public implementations of interface methods in private
* classes).</p>
*
* <p>Checks the method passed in and if it already meets these criteria it is returned
* immediately. In general this leads to very little performance overhead</p>
*
* <p>If the method does not meet the criteria then the class" interfaces are scanned
* for a matching method. If one is not found, then the class" superclass hierarchy
* is searched. Finally, if no matching method can be found the original method is
* returned.</p>
*
* @param m a method that may or may not be accessible
* @return either an accessible version of the same method, or the method passed in if
* an accessible version cannot be found
*/
public static Method findAccessibleMethod(final Method m) {
// If the passed in method is accessible, then just give it back.
if (isPublic(m.getModifiers()) && isPublic(m.getDeclaringClass().getModifiers())) return m;
if (m.isAccessible()) return m;
final Class<?> clazz = m.getDeclaringClass();
final String name = m.getName();
final Class<?>[] ptypes = m.getParameterTypes();
// Else, loop through the interfaces for the declaring class, looking for a
// public version of the method that we can call
for (Class<?> iface : clazz.getInterfaces()) {
try {
Method m2 = iface.getMethod(name, ptypes);
if (m2.isAccessible()) return m2;
if (isPublic(iface.getModifiers()) && isPublic(m2.getModifiers())) return m2;
}
catch (NoSuchMethodException nsme) { /* Not Unexpected. */ }
}
// Else loop through the superclasses looking for a public method
Class<?> c = clazz.getSuperclass();
while (c != null) {
try {
Method m2 = c.getMethod(name, ptypes);
if (m2.isAccessible()) return m2;
if (isPublic(c.getModifiers()) && isPublic(m2.getModifiers())) return m2;
}
catch (NoSuchMethodException nsme) { /* Not Unexpected. */ }
c = c.getSuperclass();
}
// If we haven"t found anything at this point, just give up!
return m;
}
/**
* Looks for an instance (i.e. non-static) public field with the matching name and
* returns it if one exists. If no such field exists, returns null.
*
* @param clazz the clazz who"s fields to examine
* @param property the name of the property/field to look for
* @return the Field object or null if no matching field exists
*/
public static Field getField(Class<?> clazz, String property) {
try {
Field field = clazz.getField(property);
return !Modifier.isStatic(field.getModifiers()) ? field : null;
}
catch (NoSuchFieldException nsfe) {
return null;
}
}
/**
* Returns an appropriate default value for the class supplied. Mirrors the defaults used
* when the JVM initializes instance variables.
*
* @param clazz the class for which to find the default value
* @return null for non-primitive types and an appropriate wrapper instance for primitives
*/
public static Object getDefaultValue(Class<?> clazz) {
if (clazz.isPrimitive()) {
return primitiveDefaults.get(clazz);
}
else {
return null;
}
}
/**
* Returns a set of all interfaces implemented by class supplied. This includes all
* interfaces directly implemented by this class as well as those implemented by
* superclasses or interface superclasses.
*
* @param clazz
* @return all interfaces implemented by this class
*/
public static Set<Class<?>> getImplementedInterfaces(Class<?> clazz)
{
Set<Class<?>> interfaces = new HashSet<Class<?>>();
if (clazz.isInterface())
interfaces.add(clazz);
while (clazz != null) {
for (Class<?> iface : clazz.getInterfaces())
interfaces.addAll(getImplementedInterfaces(iface));
clazz = clazz.getSuperclass();
}
return interfaces;
}
/**
* Returns an array of Type objects representing the actual type arguments
* to targetType used by clazz.
*
* @param clazz the implementing class (or subclass)
* @param targetType the implemented generic class or interface
* @return an array of Type objects or null
*/
public static Type[] getActualTypeArguments(Class<?> clazz, Class<?> targetType) {
Set<Class<?>> classes = new HashSet<Class<?>>();
classes.add(clazz);
if (targetType.isInterface())
classes.addAll(getImplementedInterfaces(clazz));
Class<?> superClass = clazz.getSuperclass();
while (superClass != null) {
classes.add(superClass);
superClass = superClass.getSuperclass();
}
for (Class<?> search : classes) {
for (Type type : (targetType.isInterface() ? search.getGenericInterfaces()
: new Type[] { search.getGenericSuperclass() })) {
if (type instanceof ParameterizedType) {
ParameterizedType parameterizedType = (ParameterizedType) type;
if (targetType.equals(parameterizedType.getRawType()))
return parameterizedType.getActualTypeArguments();
}
}
}
return null;
}
}
Gets a method and forces it to be accessible, even if it is not.
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
public class Main {
/**
* Gets a method and forces it to be accessible, even if it is not.
*
* @param clazz The class from which the method will be got.
* @param methodName The name of the method.
* @param parameterTypes The parameter types that the method must match.
* @return The method, if it is found.
* @since 2.0.7
*/
public static Method getForcedAccessibleMethod(Class<?> clazz,
String methodName, Class<?>... parameterTypes) {
Method method;
try {
method = clazz.getMethod(methodName, parameterTypes);
} catch (SecurityException e) {
throw new RuntimeException("Cannot access method ""
+ methodName + "" in class "" + clazz.getName()
+ "" for security reasons", e);
} catch (NoSuchMethodException e) {
throw new RuntimeException("The method ""
+ methodName + "" in class "" + clazz.getName()
+ "" does not exist", e);
}
if (!method.isAccessible()) {
method.setAccessible(true);
}
return method;
}
}
Is Accessible
/**
*
* The ObjectStyle Group Software License, version 1.1
* ObjectStyle Group - http://objectstyle.org/
*
* Copyright (c) 2002-2005, Andrei (Andrus) Adamchik and individual authors
* of the software. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. 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.
*
* 3. The end-user documentation included with the redistribution, if any,
* must include the following acknowlegement:
* "This product includes software developed by independent contributors
* and hosted on ObjectStyle Group web site (http://objectstyle.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "ObjectStyle Group" and "Cayenne" must not be used to endorse
* or promote products derived from this software without prior written
* permission. For written permission, email
* "andrus at objectstyle dot org".
*
* 5. Products derived from this software may not be called "ObjectStyle"
* or "Cayenne", nor may "ObjectStyle" or "Cayenne" appear in their
* names without prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS"" AND ANY EXPRESSED 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 OBJECTSTYLE GROUP OR
* ITS 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.
*
*
* This software consists of voluntary contributions made by many
* individuals and hosted on ObjectStyle Group web site. For more
* information on the ObjectStyle Group, please see
* <http://objectstyle.org/>.
*/
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.lang.reflect.Member;
import java.lang.reflect.Modifier;
import java.net.URL;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.ruparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.regex.Pattern;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
/**
* Contains various unorganized static utility methods used across Cayenne.
*
* @author Andrei Adamchik
*/
public class Util {
/**
* Returns true if a Member is accessible via reflection under normal Java access
* controls.
*
* @since 1.2
*/
public static boolean isAccessible(Member member) {
return Modifier.isPublic(member.getModifiers())
&& Modifier.isPublic(member.getDeclaringClass().getModifiers());
}
}
Listing the Modifiers of a Class Object
import java.lang.reflect.Modifier;
public class Main {
public static void main(String[] argv) throws Exception {
int mods = String.class.getModifiers();
if (Modifier.isPublic(mods)) {
System.out.println("class is public");
}
}
}
Listing the Modifiers of a Member Object: Field, Constructor, and Method are all subclasses of Member.
import java.lang.reflect.Modifier;
public class Main {
public static void main(String[] argv) throws Exception {
int mods = String.class.getDeclaredMethods()[0].getModifiers();
if (Modifier.isPublic(mods)) {
System.out.println("member is public");
}
}
}
Make field accessible, explicitly setting it accessible
/*
* Copyright 2002-2008 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.
*/
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.sql.SQLException;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
/**
* Simple utility class for working with the reflection API and handling
* reflection exceptions.
*
* <p>Only intended for internal use.
*
* @author Juergen Hoeller
* @author Rob Harrop
* @author Rod Johnson
* @author Costin Leau
* @since 1.2.2
*/
public abstract class ReflectionUtils {
/**
* Make the given field accessible, explicitly setting it accessible if necessary.
* The <code>setAccessible(true)</code> method is only called when actually necessary,
* to avoid unnecessary conflicts with a JVM SecurityManager (if active).
* @param field the field to make accessible
* @see java.lang.reflect.Field#setAccessible
*/
public static void makeAccessible(Field field) {
if (!Modifier.isPublic(field.getModifiers()) ||
!Modifier.isPublic(field.getDeclaringClass().getModifiers())) {
field.setAccessible(true);
}
}
}
Overriding Default Access
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
public class Main {
public static void main(String[] argv) throws Exception {
Class cls = java.lang.String.class;
Method method = cls.getMethods()[0];
Field field = cls.getFields()[0];
Constructor constructor = cls.getConstructors()[0];
field.setAccessible(true);
constructor.setAccessible(true);
method.setAccessible(true);
}
}
Return true if the integer argument includes the abstract modifier, false otherwise.
import java.lang.reflect.Modifier;
public class Main {
public static void main(String[] args) throws Exception {
getClassModifier(String.class);
getClassModifier(TestA.class);
getClassModifier(TestB.class);
}
private static void getClassModifier(Class clazz) {
int modifier = clazz.getModifiers();
if (Modifier.isAbstract(modifier)) {
System.out.println(clazz.getName() + " class modifier is abstract");
}
}
protected static final class TestA {
}
private abstract class TestB {
}
}
Return true if the integer argument includes the final modifier, false otherwise.
import java.lang.reflect.Modifier;
public class Main {
public static void main(String[] args) throws Exception {
getClassModifier(String.class);
getClassModifier(TestA.class);
getClassModifier(TestB.class);
}
private static void getClassModifier(Class clazz) {
int modifier = clazz.getModifiers();
if (Modifier.isFinal(modifier)) {
System.out.println(clazz.getName() + " class modifier is final");
}
}
protected static final class TestA {
}
private abstract class TestB {
}
}
Return true if the integer argument includes the private modifier, false otherwise.
import java.lang.reflect.Modifier;
public class Main {
public static void main(String[] args) throws Exception {
getClassModifier(String.class);
getClassModifier(TestA.class);
getClassModifier(TestB.class);
}
private static void getClassModifier(Class clazz) {
int modifier = clazz.getModifiers();
if (Modifier.isPrivate(modifier)) {
System.out.println(clazz.getName() + " class modifier is private");
}
}
protected static final class TestA {
}
private abstract class TestB {
}
}
Return true if the integer argument includes the protected modifier,false otherwise.
import java.lang.reflect.Modifier;
public class Main {
public static void main(String[] args) throws Exception {
getClassModifier(String.class);
getClassModifier(TestA.class);
getClassModifier(TestB.class);
}
private static void getClassModifier(Class clazz) {
int modifier = clazz.getModifiers();
if (Modifier.isProtected(modifier)) {
System.out.println(clazz.getName() + " class modifier is protected");
}
}
protected static final class TestA {
}
private abstract class TestB {
}
}
Return true if the integer argument includes the public modifier, false otherwise
import java.lang.reflect.Modifier;
public class Main {
public static void main(String[] args) throws Exception {
getClassModifier(String.class);
getClassModifier(TestA.class);
getClassModifier(TestB.class);
}
private static void getClassModifier(Class clazz) {
int modifier = clazz.getModifiers();
if (Modifier.isPublic(modifier)) {
System.out.println(clazz.getName() + " class modifier is public");
}
}
protected static final class TestA {
}
private abstract class TestB {
}
}
Return true if the integer argument includes the static modifier, false otherwise.
import java.lang.reflect.Modifier;
public class Main {
public static void main(String[] args) throws Exception {
getClassModifier(String.class);
getClassModifier(TestA.class);
getClassModifier(TestB.class);
}
private static void getClassModifier(Class clazz) {
int modifier = clazz.getModifiers();
if (Modifier.isStatic(modifier)) {
System.out.println(clazz.getName() + " class modifier is static");
}
}
protected static final class TestA {
}
private abstract class TestB {
}
}
Set Accessibility
// $Id: ReflectionHelper.java 16271 2009-04-07 20:20:12Z hardy.ferentschik $
/*
* JBoss, Home of Professional Open Source
* Copyright 2008, Red Hat Middleware LLC, and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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.
*/
import java.beans.Introspector;
import java.lang.annotation.Annotation;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
* Some reflection utility methods.
*
* @author Hardy Ferentschik
*/
public class ReflectionHelper {
public static void setAccessibility(Member member) {
if ( !Modifier.isPublic( member.getModifiers() ) ) {
//Sun"s ease of use, sigh...
( ( AccessibleObject ) member ).setAccessible( true );
}
}
}
