From c17287513835107ee932196055aef39364b02e92 Mon Sep 17 00:00:00 2001 From: gmungoc Date: Fri, 31 Mar 2017 12:09:02 +0100 Subject: [PATCH] JAL-2472 PrivilegedAccessor added --- test/junit/extensions/PA.java | 331 +++++++++++++ test/junit/extensions/PrivilegedAccessor.java | 647 +++++++++++++++++++++++++ 2 files changed, 978 insertions(+) create mode 100644 test/junit/extensions/PA.java create mode 100644 test/junit/extensions/PrivilegedAccessor.java diff --git a/test/junit/extensions/PA.java b/test/junit/extensions/PA.java new file mode 100644 index 0000000..57c873f --- /dev/null +++ b/test/junit/extensions/PA.java @@ -0,0 +1,331 @@ +/* + * Copyright 2004-2012 Sebastian Dietrich (Sebastian.Dietrich@e-movimento.com) + * + * 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 junit.extensions; + +import java.util.Collection; + +/** + * This class is used to access a method or field of an object no matter what the access modifier of the method or field. The syntax + * for accessing fields and methods is out of the ordinary because this class uses reflection to peel away protection. + *

+ * a.k.a. The "ObjectMolester" + *

+ * Here is an example of using this to access a private member:
+ * Given the following class MyClass:
+ * + * 

+ * public class MyClass {
+ *    private String name; // private attribute
+ * 
+ *    // private constructor
+ *    private MyClass() {
+ *       super();
+ *    }
+ * 
+ *    // private method
+ *    private void setName(String newName) {
+ *       this.name = newName;
+ *    }
+ * }
+ *
+ * + * We now want to access the class:
+ * + * 
+ * MyClass myObj = PA.instantiate(MyClass.class);
+ * PA.invokeMethod(myObj, "setName(java.lang.String)", "myNewName");
+ * String name = PA.getValue(myObj, "name");
+ *
+ * + * This class extends {@link PrivilegedAccessor} by re-throwing checked {@link Exception}s as {@link RuntimeException}s. + * + * + * @see PrivilegedAccessor + * + * @author Sebastian Dietrich (sebastian.dietrich@e-movimento.com) + * @author Lubos Bistak (lubos@bistak.sk) + */ +public class PA { + private final Object instanceOrClass; + + /** + * Private constructor to make it impossible to instantiate this class from outside of PA. + * + * @param instanceOrClass + */ + private PA(Object instanceOrClass) { + this.instanceOrClass = instanceOrClass; + } + + /** + * Returns a string representation of the given object. The string has the following format: " {}" + * whereas is a comma separated list with = includes + * all attributes of the objects class followed by the attributes of its superclass (if any) and so on. + * + * @param instanceOrClass the object or class to get a string representation of + * @return a string representation of the given object + * + * @see PrivilegedAccessor#toString(Object) + */ + public static String toString(final Object instanceOrClass) { + return PrivilegedAccessor.toString(instanceOrClass); + } + + /** + * Gets the name of all fields (public, private, protected, default) of the given instance or class. This includes as well all + * fields (public, private, protected, default) of all its super classes. + * + * @param instanceOrClass the instance or class to get the fields of + * @return the collection of field names of the given instance or class + * + * @see PrivilegedAccessor#getFieldNames(Object) + */ + public static Collection getFieldNames(final Object instanceOrClass) { + return PrivilegedAccessor.getFieldNames(instanceOrClass); + } + + /** + * Gets the signatures of all methods (public, private, protected, default) of the given instance or class. This includes as well + * all methods (public, private, protected, default) of all its super classes. This does not include constructors. + * + * @param instanceOrClass the instance or class to get the method signatures of + * @return the collection of method signatures of the given instance or class + * + * @see PrivilegedAccessor#getMethodSignatures(Object) + */ + public static Collection getMethodSignatures(final Object instanceOrClass) { + return PrivilegedAccessor.getMethodSignatures(instanceOrClass); + } + + /** + * Gets the value of the named field and returns it as an object. If instanceOrClass is a class then a static field is returned. + * + * @param instanceOrClass the instance or class to get the field from + * @param fieldName the name of the field + * @return an object representing the value of the field + * @throws IllegalArgumentException if the field does not exist + * + * @see PrivilegedAccessor#getValue(Object,String) + */ + public static Object getValue(final Object instanceOrClass, final String fieldName) { + try { + return PrivilegedAccessor.getValue(instanceOrClass, fieldName); + } catch (Exception e) { + throw new IllegalArgumentException("Can't get value of " + fieldName + " from " + instanceOrClass, e); + } + } + + /** + * Gets the value of the named field and returns it as an object. + * + * @param fieldName the name of the field + * @return an object representing the value of the field + * @throws IllegalArgumentException if the field does not exist + * + * @see PA#getValue(Object,String) + */ + public Object getValue(final String fieldName) { + return PA.getValue(instanceOrClass, fieldName); + } + + /** + * Instantiates an object of the given class with the given arguments and the given argument types. If you want to instantiate a + * member class, you must provide the object it is a member of as first argument. + * + * @param fromClass the class to instantiate an object from + * @param arguments the arguments to pass to the constructor + * @param argumentTypes the fully qualified types of the arguments of the constructor + * @return an object of the given type + * @throws IllegalArgumentException if the class can't be instantiated. This could be the case if the number of actual and formal + * parameters differ; if an unwrapping conversion for primitive arguments fails; if, after possible unwrapping, a + * parameter value cannot be converted to the corresponding formal parameter type by a method invocation conversion; if + * this Constructor object enforces Java language access control and the underlying constructor is inaccessible; if the + * underlying constructor throws an exception; if the constructor could not be found; or if the class that declares the + * underlying constructor represents an abstract class. + * + * @see PrivilegedAccessor#instantiate(Class,Class[],Object[]) + */ + public static T instantiate(final Class fromClass, final Class[] argumentTypes, final Object... arguments) { + try { + return PrivilegedAccessor.instantiate(fromClass, argumentTypes, correctVarargs(arguments)); + } catch (Exception e) { + throw new IllegalArgumentException("Can't instantiate class " + fromClass + " with arguments " + arguments, e); + } + } + + /** + * Instantiates an object of the given class with the given arguments. If you want to instantiate a member class, you must provide + * the object it is a member of as first argument. + * + * @param fromClass the class to instantiate an object from + * @param arguments the arguments to pass to the constructor + * @return an object of the given type + * @throws IllegalArgumentException if the class can't be instantiated. This could be the case if the number of actual and formal + * parameters differ; if an unwrapping conversion for primitive arguments fails; or if, after possible unwrapping, a + * parameter value cannot be converted to the corresponding formal parameter type by a method invocation conversion; if + * this Constructor object enforces Java language access control and the underlying constructor is inaccessible; if the + * underlying constructor throws an exception; if the constructor could not be found; or if the class that declares the + * underlying constructor represents an abstract class. + * + * @see PrivilegedAccessor#instantiate(Class,Object[]) + */ + public static T instantiate(final Class fromClass, final Object... arguments) { + try { + return PrivilegedAccessor.instantiate(fromClass, correctVarargs(arguments)); + } catch (Exception e) { + throw new IllegalArgumentException("Can't instantiate class " + fromClass + " with arguments " + arguments, e); + } + } + + /** + * Calls a method on the given object instance with the given arguments. Arguments can be object types or representations for + * primitives. + * + * @param instanceOrClass the instance or class to invoke the method on + * @param methodSignature the name of the method and the parameters
+ * (e.g. "myMethod(java.lang.String, com.company.project.MyObject)") + * @param arguments an array of objects to pass as arguments + * @return the return value of this method or null if void + * @throws IllegalArgumentException if the method could not be invoked. This could be the case if the method is inaccessible; if the + * underlying method throws an exception; if no method with the given methodSignature could be found; or if + * an argument couldn't be converted to match the expected type + * + * @see PrivilegedAccessor#invokeMethod(Object,String,Object[]) + */ + public static Object invokeMethod(final Object instanceOrClass, final String methodSignature, final Object... arguments) { + try { + return PrivilegedAccessor.invokeMethod(instanceOrClass, methodSignature, correctVarargs(arguments)); + } catch (Exception e) { + throw new IllegalArgumentException("Can't invoke method " + methodSignature + " on " + instanceOrClass + " with arguments " + + arguments, e); + } + } + + /** + * Calls a method with the given arguments. Arguments can be object types or representations for primitives. + * + * @param methodSignature the name of the method and the parameters
+ * (e.g. "myMethod(java.lang.String, com.company.project.MyObject)") + * @param arguments an array of objects to pass as arguments + * @return the return value of this method or null if void + * @throws IllegalArgumentException if the method could not be invoked. This could be the case if the method is inaccessible; if the + * underlying method throws an exception; if no method with the given methodSignature could be found; or if + * an argument couldn't be converted to match the expected type + * @see PA#invokeMethod(Object, String, Object...) + */ + public Object invokeMethod(final String methodSignature, final Object... arguments) { + return PA.invokeMethod(instanceOrClass, methodSignature, arguments); + } + + /** + * Corrects varargs to their initial form. If you call a method with an object-array as last argument the Java varargs mechanism + * converts this array in single arguments. This method returns an object array if the arguments are all of the same type. + * + * @param arguments the possibly converted arguments of a vararg method + * @return arguments possibly converted + */ + private static Object[] correctVarargs(final Object... arguments) { + if ((arguments == null) || changedByVararg(arguments)) return new Object[] {arguments}; + return arguments; + } + + /** + * Tests if the arguments were changed by vararg. Arguments are changed by vararg if they are of a non primitive array type. E.g. + * arguments[] = Object[String[]] is converted to String[] while e.g. arguments[] = Object[int[]] is not converted and stays + * Object[int[]] + * + * Unfortunately we can't detect the difference for arg = Object[primitive] since arguments[] = Object[Object[primitive]] which is + * converted to Object[primitive] and arguments[] = Object[primitive] which stays Object[primitive] + * + * and we can't detect the difference for arg = Object[non primitive] since arguments[] = Object[Object[non primitive]] is converted + * to Object[non primitive] and arguments[] = Object[non primitive] stays Object[non primitive] + * + * @param parameters the parameters + * @return true if parameters were changes by varargs, false otherwise + */ + private static boolean changedByVararg(final Object[] parameters) { + if ((parameters.length == 0) || (parameters[0] == null)) return false; + + if (parameters.getClass() == Object[].class) return false; + + return true; + } + + /** + * Sets the value of the named field. If fieldName denotes a static field, provide a class, otherwise provide an instance. If the + * fieldName denotes a final field, this method could fail with an IllegalAccessException, since setting the value of final fields + * at other times than instantiation can have unpredictable effects.
+ *
+ * Example:
+ *
+ * + * String myString = "Test";
+ *
+ * //setting the private field value
+ * PrivilegedAccessor.setValue(myString, "value", new char[] {'T', 'e', 's', 't'});
+ *
+ * //setting the static final field serialVersionUID - MIGHT FAIL
+ * PrivilegedAccessor.setValue(myString.getClass(), "serialVersionUID", 1);
+ *
+ * + * + * @param instanceOrClass the instance or class to set the field + * @param fieldName the name of the field + * @param value the new value of the field + * @throws IllegalArgumentException if the value could not be set. This could be the case if no field with the given + * fieldName can be found; or if the field was final + * + * @see PrivilegedAccessor.setValue(Object,String,Object) + */ + public static PA setValue(final Object instanceOrClass, final String fieldName, final Object value) { + try { + PrivilegedAccessor.setValue(instanceOrClass, fieldName, value); + } catch (Exception e) { + throw new IllegalArgumentException("Can't set value " + value + " at " + fieldName + " in " + instanceOrClass, e); + } + return new PA(instanceOrClass); + } + + /** + * Sets the value of the named field. If fieldName denotes a static field, provide a class, otherwise provide an instance. If the + * fieldName denotes a final field, this method could fail with an IllegalAccessException, since setting the value of final fields + * at other times than instantiation can have unpredictable effects.
+ *
+ * Example:
+ *
+ * + * String myString = "Test";
+ *
+ * //setting the private field value
+ * PrivilegedAccessor.setValue(myString, "value", new char[] {'T', 'e', 's', 't'});
+ *
+ * //setting the static final field serialVersionUID - MIGHT FAIL
+ * PrivilegedAccessor.setValue(myString.getClass(), "serialVersionUID", 1);
+ *
+ * + * + * @param fieldName the name of the field + * @param value the new value of the field + * @throws IllegalArgumentException if the value could not be set. This could be the case if no field with the given + * fieldName can be found; or if the field was final + * + * @see PA.setValue(Object,String,Object) + */ + public PA setValue(final String fieldName, final Object value) { + PA.setValue(instanceOrClass, fieldName, value); + return this; + } +} diff --git a/test/junit/extensions/PrivilegedAccessor.java b/test/junit/extensions/PrivilegedAccessor.java new file mode 100644 index 0000000..23f1c6e --- /dev/null +++ b/test/junit/extensions/PrivilegedAccessor.java @@ -0,0 +1,647 @@ +/* + * Copyright 2004-2012 Sebastian Dietrich (Sebastian.Dietrich@e-movimento.com) + * + * 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 junit.extensions; + +import java.lang.reflect.Array; +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.security.InvalidParameterException; +import java.util.ArrayList; +import java.util.Collection; +import java.util.Collections; +import java.util.HashMap; +import java.util.Map; +import java.util.StringTokenizer; + +/** + * This class is used to access a method or field of an object no matter what the access modifier of the method or field. The syntax + * for accessing fields and methods is out of the ordinary because this class uses reflection to peel away protection. + *

+ * a.k.a. The "ObjectMolester" + *

+ * Here is an example of using this to access a private member:
+ * myObject is an object of type MyClass. setName(String) is a private method of + * MyClass. + * + * 

+ * PrivilegedAccessor.invokeMethod(myObject, "setName(java.lang.String)", "newName");
+ *
+ * + * @author Charlie Hubbard (chubbard@iss.net) + * @author Prashant Dhokte (pdhokte@iss.net) + * @author Sebastian Dietrich (sebastian.dietrich@e-movimento.com) + * + * @deprecated use PA instead. PA improves the functionality of PrivilegedAccessor by introducing support for varargs and removal of + * the necessity to catch exceptions. + */ +@Deprecated +final class PrivilegedAccessor +{ + /** + * Private constructor to make it impossible to instantiate this class. + */ + private PrivilegedAccessor() { + assert false : "You mustn't instantiate PrivilegedAccessor, use its methods statically"; + } + + /** + * Returns a string representation of the given object. The string has the following format: " {}" + * whereas is a comma separated list with = includes + * all attributes of the objects class followed by the attributes of its superclass (if any) and so on. + * + * @param instanceOrClass the object or class to get a string representation of + * @return a string representation of the given object + */ + public static String toString(final Object instanceOrClass) { + Collection fields = getFieldNames(instanceOrClass); + + if (fields.isEmpty()) + { + return getClass(instanceOrClass).getName(); + } + + StringBuffer stringBuffer = new StringBuffer(); + + stringBuffer.append(getClass(instanceOrClass).getName() + " {"); + + for (String fieldName : fields) { + try { + stringBuffer.append(fieldName + "=" + getValue(instanceOrClass, fieldName) + ", "); + } catch (NoSuchFieldException e) { + assert false : "It should always be possible to get a field that was just here"; + } + } + + stringBuffer.replace(stringBuffer.lastIndexOf(", "), stringBuffer.length(), "}"); + return stringBuffer.toString(); + } + + /** + * Gets the name of all fields (public, private, protected, default) of the given instance or class. This includes as well all + * fields (public, private, protected, default) of all its super classes. + * + * @param instanceOrClass the instance or class to get the fields of + * @return the collection of field names of the given instance or class + */ + public static Collection getFieldNames(final Object instanceOrClass) { + if (instanceOrClass == null) + { + return Collections.EMPTY_LIST; + } + + Class clazz = getClass(instanceOrClass); + Field[] fields = clazz.getDeclaredFields(); + Collection fieldNames = new ArrayList(fields.length); + + for (Field field : fields) { + fieldNames.add(field.getName()); + } + fieldNames.addAll(getFieldNames(clazz.getSuperclass())); + + return fieldNames; + } + + /** + * Gets the signatures of all methods (public, private, protected, default) of the given instance or class. This includes as well + * all methods (public, private, protected, default) of all its super classes. This does not include constructors. + * + * @param instanceOrClass the instance or class to get the method signatures of + * @return the collection of method signatures of the given instance or class + */ + public static Collection getMethodSignatures(final Object instanceOrClass) { + if (instanceOrClass == null) + { + return Collections.EMPTY_LIST; + } + + Class clazz = getClass(instanceOrClass); + Method[] methods = clazz.getDeclaredMethods(); + Collection methodSignatures = new ArrayList(methods.length + Object.class.getDeclaredMethods().length); + + for (Method method : methods) { + methodSignatures.add(method.getName() + "(" + getParameterTypesAsString(method.getParameterTypes()) + ")"); + } + methodSignatures.addAll(getMethodSignatures(clazz.getSuperclass())); + + return methodSignatures; + } + + /** + * Gets the value of the named field and returns it as an object. If instanceOrClass is a class then a static field is returned. + * + * @param instanceOrClass the instance or class to get the field from + * @param fieldName the name of the field + * @return an object representing the value of the field + * @throws NoSuchFieldException if the field does not exist + */ + public static Object getValue(final Object instanceOrClass, final String fieldName) throws NoSuchFieldException { + Field field = getField(instanceOrClass, fieldName); + try { + return field.get(instanceOrClass); + } catch (IllegalAccessException e) { + assert false : "getField() should have setAccessible(true), so an IllegalAccessException should not occur in this place"; + return null; + } + } + + /** + * Instantiates an object of the given class with the given arguments. If you want to instantiate a member class, you must provide + * the object it is a member of as first argument. + * + * @param fromClass the class to instantiate an object from + * @param args the arguments to pass to the constructor + * @return an object of the given type + * @throws IllegalArgumentException if the number of actual and formal parameters differ; if an unwrapping conversion for primitive + * arguments fails; or if, after possible unwrapping, a parameter value cannot be converted to the corresponding formal + * parameter type by a method invocation conversion. + * @throws IllegalAccessException if this Constructor object enforces Java language access control and the underlying constructor is + * inaccessible. + * @throws InvocationTargetException if the underlying constructor throws an exception. + * @throws NoSuchMethodException if the constructor could not be found + * @throws InstantiationException if the class that declares the underlying constructor represents an abstract class. + * + * @see PrivilegedAccessor#instantiate(Class,Class[],Object[]) + */ + public static T instantiate(final Class fromClass, final Object[] args) throws IllegalArgumentException, + InstantiationException, IllegalAccessException, InvocationTargetException, NoSuchMethodException { + return instantiate(fromClass, getParameterTypes(args), args); + } + + /** + * Instantiates an object of the given class with the given arguments and the given argument types. If you want to instantiate a + * member class, you must provide the object it is a member of as first argument. + * + * + * @param fromClass the class to instantiate an object from + * @param args the arguments to pass to the constructor + * @param argumentTypes the fully qualified types of the arguments of the constructor + * @return an object of the given type + * @throws IllegalArgumentException if the number of actual and formal parameters differ; if an unwrapping conversion for primitive + * arguments fails; or if, after possible unwrapping, a parameter value cannot be converted to the corresponding formal + * parameter type by a method invocation conversion. + * @throws IllegalAccessException if this Constructor object enforces Java language access control and the underlying constructor is + * inaccessible. + * @throws InvocationTargetException if the underlying constructor throws an exception. + * @throws NoSuchMethodException if the constructor could not be found + * @throws InstantiationException if the class that declares the underlying constructor represents an abstract class. + * + * @see PrivilegedAccessor#instantiate(Class,Object[]) + */ + public static T instantiate(final Class fromClass, final Class[] argumentTypes, final Object[] args) + throws IllegalArgumentException, InstantiationException, IllegalAccessException, InvocationTargetException, + NoSuchMethodException { + return getConstructor(fromClass, argumentTypes).newInstance(args); + } + + /** + * Calls a method on the given object instance with the given arguments. Arguments can be object types or representations for + * primitives. + * + * @param instanceOrClass the instance or class to invoke the method on + * @param methodSignature the name of the method and the parameters
+ * (e.g. "myMethod(java.lang.String, com.company.project.MyObject)") + * @param arguments an array of objects to pass as arguments + * @return the return value of this method or null if void + * @throws IllegalAccessException if the method is inaccessible + * @throws InvocationTargetException if the underlying method throws an exception. + * @throws NoSuchMethodException if no method with the given methodSignature could be found + * @throws IllegalArgumentException if an argument couldn't be converted to match the expected type + */ + public static Object invokeMethod(final Object instanceOrClass, final String methodSignature, final Object[] arguments) + throws IllegalArgumentException, IllegalAccessException, InvocationTargetException, NoSuchMethodException { + if ((methodSignature.indexOf('(') == -1) || (methodSignature.indexOf('(') >= methodSignature.indexOf(')'))) + { + throw new NoSuchMethodException(methodSignature); + } + Class[] parameterTypes = getParameterTypes(methodSignature); + return getMethod(instanceOrClass, getMethodName(methodSignature), parameterTypes).invoke(instanceOrClass, + getCorrectedArguments(parameterTypes, arguments)); + } + + /** + * Gets the given arguments corrected to match the given methodSignature. Correction is necessary for array arguments not to be + * mistaken by varargs. + * + * @param parameterTypes the method signatue the given arguments should match + * @param arguments the arguments that should be corrected + * @return the corrected arguments + */ + private static Object[] getCorrectedArguments(Class[] parameterTypes, Object[] arguments) { + if (arguments == null) + { + return arguments; + } + if (parameterTypes.length > arguments.length) + { + return arguments; + } + if (parameterTypes.length < arguments.length) + { + return getCorrectedArguments(parameterTypes, new Object[] {arguments}); + } + + Object[] correctedArguments = new Object[arguments.length]; + int currentArgument = 0; + for (Class parameterType : parameterTypes) { + correctedArguments[currentArgument] = getCorrectedArgument(parameterType, arguments[currentArgument]); + currentArgument++; + } + return correctedArguments; + } + + /** + * Gets the given argument corrected to match the given parameterType. Correction is necessary for array arguments not to be + * mistaken by varargs. + * + * @param parameterType the type to match the given argument upon + * @param argument the argument to match the given parameterType + * @return the corrected argument + */ + private static Object getCorrectedArgument(Class parameterType, Object argument) { + if (!parameterType.isArray() || (argument == null)) { + return argument; // normal argument for normal parameterType + } + + if (!argument.getClass().isArray()) { + return new Object[] {argument}; + } + + if (parameterType.equals(argument.getClass())) + { + return argument; // no need to cast + } + + // (typed) array argument for (object) array parameterType, elements need to be casted + Object correctedArrayArgument = Array.newInstance(parameterType.getComponentType(), Array.getLength(argument)); + for (int index = 0; index < Array.getLength(argument); index++) { + if (parameterType.getComponentType().isPrimitive()) { // rely on autoboxing + Array.set(correctedArrayArgument, index, Array.get(argument, index)); + } else { // cast to expected type + try { + Array.set(correctedArrayArgument, index, parameterType.getComponentType().cast(Array.get(argument, index))); + } catch (ClassCastException e) { + throw new IllegalArgumentException("Argument " + argument + " of type " + argument.getClass() + + " does not match expected argument type " + parameterType + "."); + } + } + } + return correctedArrayArgument; + } + + /** + * Sets the value of the named field. If fieldName denotes a static field, provide a class, otherwise provide an instance. If the + * fieldName denotes a final field, this method could fail with an IllegalAccessException, since setting the value of final fields + * at other times than instantiation can have unpredictable effects.
+ *
+ * Example:
+ *
+ * + * String myString = "Test";
+ *
+ * //setting the private field value
+ * PrivilegedAccessor.setValue(myString, "value", new char[] {'T', 'e', 's', 't'});
+ *
+ * //setting the static final field serialVersionUID - MIGHT FAIL
+ * PrivilegedAccessor.setValue(myString.getClass(), "serialVersionUID", 1);
+ *
+ * + * + * @param instanceOrClass the instance or class to set the field + * @param fieldName the name of the field + * @param value the new value of the field + * @throws NoSuchFieldException if no field with the given fieldName can be found + * @throws IllegalAccessException possibly if the field was final + */ + public static void setValue(final Object instanceOrClass, final String fieldName, final Object value) throws NoSuchFieldException, + IllegalAccessException { + Field field = getField(instanceOrClass, fieldName); + if (Modifier.isFinal(field.getModifiers())) { + PrivilegedAccessor.setValue(field, "modifiers", field.getModifiers() ^ Modifier.FINAL); + } + field.set(instanceOrClass, value); + } + + /** + * Gets the class with the given className. + * + * @param className the name of the class to get + * @return the class for the given className + * @throws ClassNotFoundException if the class could not be found + */ + private static Class getClassForName(final String className) throws ClassNotFoundException { + if (className.indexOf('[') > -1) { + Class clazz = getClassForName(className.substring(0, className.indexOf('['))); + return Array.newInstance(clazz, 0).getClass(); + } + + if (className.indexOf("...") > -1) { + Class clazz = getClassForName(className.substring(0, className.indexOf("..."))); + return Array.newInstance(clazz, 0).getClass(); + } + + try { + return Class.forName(className, false, Thread.currentThread().getContextClassLoader()); + } catch (ClassNotFoundException e) { + return getSpecialClassForName(className); + } + } + + /** + * Maps string representation of primitives to their corresponding classes. + */ + private static final Map> PRIMITIVE_MAPPER = new HashMap>(8); + + /** + * Fills the map with all java primitives and their corresponding classes. + */ + static { + PRIMITIVE_MAPPER.put("int", Integer.TYPE); + PRIMITIVE_MAPPER.put("float", Float.TYPE); + PRIMITIVE_MAPPER.put("double", Double.TYPE); + PRIMITIVE_MAPPER.put("short", Short.TYPE); + PRIMITIVE_MAPPER.put("long", Long.TYPE); + PRIMITIVE_MAPPER.put("byte", Byte.TYPE); + PRIMITIVE_MAPPER.put("char", Character.TYPE); + PRIMITIVE_MAPPER.put("boolean", Boolean.TYPE); + } + + /** + * Gets special classes for the given className. Special classes are primitives and "standard" Java types (like String) + * + * @param className the name of the class to get + * @return the class for the given className + * @throws ClassNotFoundException if the class could not be found + */ + private static Class getSpecialClassForName(final String className) throws ClassNotFoundException { + if (PRIMITIVE_MAPPER.containsKey(className)) + { + return PRIMITIVE_MAPPER.get(className); + } + + if (missesPackageName(className)) + { + return getStandardClassForName(className); + } + + throw new ClassNotFoundException(className); + } + + /** + * Gets a 'standard' java class for the given className. + * + * @param className the className + * @return the class for the given className (if any) + * @throws ClassNotFoundException of no 'standard' java class was found for the given className + */ + private static Class getStandardClassForName(String className) throws ClassNotFoundException { + try { + return Class.forName("java.lang." + className, false, Thread.currentThread().getContextClassLoader()); + } catch (ClassNotFoundException e) { + try { + return Class.forName("java.util." + className, false, Thread.currentThread().getContextClassLoader()); + } catch (ClassNotFoundException e1) { + throw new ClassNotFoundException(className); + } + } + } + + /** + * Tests if the given className possibly misses its package name. + * + * @param className the className + * @return true if the className might miss its package name, otherwise false + */ + private static boolean missesPackageName(String className) { + if (className.contains(".")) + { + return false; + } + if (className.startsWith(className.substring(0, 1).toUpperCase())) + { + return true; + } + return false; + } + + /** + * Gets the constructor for a given class with the given parameters. + * + * @param type the class to instantiate + * @param parameterTypes the types of the parameters + * @return the constructor + * @throws NoSuchMethodException if the method could not be found + */ + private static Constructor getConstructor(final Class type, final Class[] parameterTypes) throws NoSuchMethodException { + Constructor constructor = type.getDeclaredConstructor(parameterTypes); + constructor.setAccessible(true); + return constructor; + } + + /** + * Return the named field from the given instance or class. Returns a static field if instanceOrClass is a class. + * + * @param instanceOrClass the instance or class to get the field from + * @param fieldName the name of the field to get + * @return the field + * @throws NoSuchFieldException if no such field can be found + * @throws InvalidParameterException if instanceOrClass was null + */ + private static Field getField(final Object instanceOrClass, final String fieldName) throws NoSuchFieldException, + InvalidParameterException { + if (instanceOrClass == null) + { + throw new InvalidParameterException("Can't get field on null object/class"); + } + + Class type = getClass(instanceOrClass); + + try { + Field field = type.getDeclaredField(fieldName); + field.setAccessible(true); + return field; + } catch (NoSuchFieldException e) { + if (type.getSuperclass() == null) + { + throw e; + } + return getField(type.getSuperclass(), fieldName); + } + } + + /** + * Gets the class of the given parameter. If the parameter is a class, it is returned, if it is an object, its class is returned + * + * @param instanceOrClass the instance or class to get the class of + * @return the class of the given parameter + */ + private static Class getClass(final Object instanceOrClass) { + if (instanceOrClass instanceof Class) + { + return (Class) instanceOrClass; + } + + return instanceOrClass.getClass(); + } + + /** + * Return the named method with a method signature matching classTypes from the given class. + * + * @param type the class to get the method from + * @param methodName the name of the method to get + * @param parameterTypes the parameter-types of the method to get + * @return the method + * @throws NoSuchMethodException if the method could not be found + */ + private static Method getMethod(final Class type, final String methodName, final Class[] parameterTypes) + throws NoSuchMethodException { + try { + return type.getDeclaredMethod(methodName, parameterTypes); + } catch (NoSuchMethodException e) { + if (type.getSuperclass() == null) + { + throw e; + } + return getMethod(type.getSuperclass(), methodName, parameterTypes); + } + } + + /** + * Gets the method with the given name and parameters from the given instance or class. If instanceOrClass is a class, then we get a + * static method. + * + * @param instanceOrClass the instance or class to get the method of + * @param methodName the name of the method + * @param parameterTypes the parameter-types of the method to get + * @return the method + * @throws NoSuchMethodException if the method could not be found + */ + private static Method getMethod(final Object instanceOrClass, final String methodName, final Class[] parameterTypes) + throws NoSuchMethodException { + Class type; + + type = getClass(instanceOrClass); + + Method accessMethod = getMethod(type, methodName, parameterTypes); + accessMethod.setAccessible(true); + return accessMethod; + } + + /** + * Gets the name of a method. + * + * @param methodSignature the signature of the method + * @return the name of the method + */ + private static String getMethodName(final String methodSignature) { + try { + return methodSignature.substring(0, methodSignature.indexOf('(')).trim(); + } catch (StringIndexOutOfBoundsException e) { + assert false : "Signature must have been checked before this method was called"; + return null; + } + } + + /** + * Gets the types of the parameters. + * + * @param parameters the parameters + * @return the class-types of the arguments + */ + private static Class[] getParameterTypes(final Object[] parameters) { + if (parameters == null) + { + return new Class[0]; + } + + Class[] typesOfParameters = new Class[parameters.length]; + + for (int i = 0; i < parameters.length; i++) { + typesOfParameters[i] = parameters[i].getClass(); + } + return typesOfParameters; + } + + /** + * Gets the types of the given parameters. If the parameters don't match the given methodSignature an IllegalArgumentException is + * thrown. + * + * @param methodSignature the signature of the method + * @return the parameter types as class[] + * @throws NoSuchMethodException if the method could not be found + * @throws IllegalArgumentException if one of the given parameters doesn't math the given methodSignature + */ + private static Class[] getParameterTypes(final String methodSignature) throws NoSuchMethodException, IllegalArgumentException { + String signature = getSignatureWithoutBraces(methodSignature); + + StringTokenizer tokenizer = new StringTokenizer(signature, ", *"); + Class[] typesInSignature = new Class[tokenizer.countTokens()]; + + for (int x = 0; tokenizer.hasMoreTokens(); x++) { + String className = tokenizer.nextToken(); + try { + typesInSignature[x] = getClassForName(className); + } catch (ClassNotFoundException e) { + NoSuchMethodException noSuchMethodException = new NoSuchMethodException(methodSignature); + noSuchMethodException.initCause(e); + throw noSuchMethodException; + } + } + return typesInSignature; + } + + /** + * Gets the parameter types as a string. + * + * @param classTypes the types to get as names. + * @return the parameter types as a string + * + * @see java.lang.Class#argumentTypesToString(Class[]) + */ + private static String getParameterTypesAsString(final Class[] classTypes) { + assert classTypes != null : "getParameterTypes() should have been called before this method and should have provided not-null classTypes"; + if (classTypes.length == 0) + { + return ""; + } + + StringBuilder parameterTypes = new StringBuilder(); + for (Class clazz : classTypes) { + assert clazz != null : "getParameterTypes() should have been called before this method and should have provided not-null classTypes"; + parameterTypes.append(clazz.getName()).append(", "); + } + + return parameterTypes.substring(0, parameterTypes.length() - 2); + } + + /** + * Removes the braces around the methods signature. + * + * @param methodSignature the signature with braces + * @return the signature without braces + */ + private static String getSignatureWithoutBraces(final String methodSignature) { + try { + return methodSignature.substring(methodSignature.indexOf('(') + 1, methodSignature.indexOf(')')); + } catch (IndexOutOfBoundsException e) { + assert false : "signature must have been checked before this method"; + return null; + } + } + +} -- 1.7.10.2