| package org.codehaus.jackson.map.util; |
| |
| import java.lang.reflect.*; |
| import java.util.*; |
| |
| public final class ClassUtil |
| { |
| /* |
| /********************************************************** |
| /* Methods that deal with inheritance |
| /********************************************************** |
| */ |
| |
| /** |
| * Method that will find all sub-classes and implemented interfaces |
| * of a given class or interface. Classes are listed in order of |
| * precedence, starting with the immediate super-class, followed by |
| * interfaces class directly declares to implemented, and then recursively |
| * followed by parent of super-class and so forth. |
| * Note that <code>Object.class</code> is not included in the list |
| * regardless of whether <code>endBefore</code> argument is defined or not. |
| * |
| * @param endBefore Super-type to NOT include in results, if any; when |
| * encountered, will be ignored (and no super types are checked). |
| */ |
| public static List<Class<?>> findSuperTypes(Class<?> cls, Class<?> endBefore) |
| { |
| return findSuperTypes(cls, endBefore, new ArrayList<Class<?>>(8)); |
| } |
| |
| public static List<Class<?>> findSuperTypes(Class<?> cls, Class<?> endBefore, List<Class<?>> result) |
| { |
| _addSuperTypes(cls, endBefore, result, false); |
| return result; |
| } |
| |
| private static void _addSuperTypes(Class<?> cls, Class<?> endBefore, Collection<Class<?>> result, boolean addClassItself) |
| { |
| if (cls == endBefore || cls == null || cls == Object.class) { |
| return; |
| } |
| if (addClassItself) { |
| if (result.contains(cls)) { // already added, no need to check supers |
| return; |
| } |
| result.add(cls); |
| } |
| for (Class<?> intCls : cls.getInterfaces()) { |
| _addSuperTypes(intCls, endBefore, result, true); |
| } |
| _addSuperTypes(cls.getSuperclass(), endBefore, result, true); |
| } |
| |
| /* |
| /********************************************************** |
| /* Class type detection methods |
| /********************************************************** |
| */ |
| |
| /** |
| * @return Null if class might be a bean; type String (that identifies |
| * why it's not a bean) if not |
| */ |
| public static String canBeABeanType(Class<?> type) |
| { |
| // First: language constructs that ain't beans: |
| if (type.isAnnotation()) { |
| return "annotation"; |
| } |
| if (type.isArray()) { |
| return "array"; |
| } |
| if (type.isEnum()) { |
| return "enum"; |
| } |
| if (type.isPrimitive()) { |
| return "primitive"; |
| } |
| |
| // Anything else? Seems valid, then |
| return null; |
| } |
| |
| /** |
| * @deprecated since 1.9, use variant that takes second argument |
| */ |
| @Deprecated |
| public static String isLocalType(Class<?> type) { |
| return isLocalType(type, false); |
| } |
| |
| /** |
| * @since 1.9 |
| */ |
| public static String isLocalType(Class<?> type, boolean allowNonStatic) |
| { |
| /* As per [JACKSON-187], GAE seems to throw SecurityExceptions |
| * here and there... and GAE itself has a bug, too |
| * (see []). Bah. So we need to catch some wayward exceptions on GAE |
| */ |
| try { |
| // one more: method locals, anonymous, are not good: |
| if (type.getEnclosingMethod() != null) { |
| return "local/anonymous"; |
| } |
| |
| /* But how about non-static inner classes? Can't construct |
| * easily (theoretically, we could try to check if parent |
| * happens to be enclosing... but that gets convoluted) |
| */ |
| if (!allowNonStatic) { |
| if (type.getEnclosingClass() != null) { |
| if (!Modifier.isStatic(type.getModifiers())) { |
| return "non-static member class"; |
| } |
| } |
| } |
| } |
| catch (SecurityException e) { } |
| catch (NullPointerException e) { } |
| return null; |
| } |
| |
| /** |
| * Method for finding enclosing class for non-static inner classes |
| * |
| * @since 1.9 |
| */ |
| public static Class<?> getOuterClass(Class<?> type) |
| { |
| // as above, GAE has some issues... |
| try { |
| // one more: method locals, anonymous, are not good: |
| if (type.getEnclosingMethod() != null) { |
| return null; |
| } |
| if (!Modifier.isStatic(type.getModifiers())) { |
| return type.getEnclosingClass(); |
| } |
| } catch (SecurityException e) { } |
| catch (NullPointerException e) { } |
| return null; |
| } |
| |
| |
| /** |
| * Helper method used to weed out dynamic Proxy types; types that do |
| * not expose concrete method API that we could use to figure out |
| * automatic Bean (property) based serialization. |
| */ |
| public static boolean isProxyType(Class<?> type) |
| { |
| // As per [Issue#57], should NOT disqualify JDK proxy: |
| /* |
| if (Proxy.isProxyClass(type)) { |
| return true; |
| } |
| */ |
| String name = type.getName(); |
| // Hibernate uses proxies heavily as well: |
| if (name.startsWith("net.sf.cglib.proxy.") |
| || name.startsWith("org.hibernate.proxy.")) { |
| return true; |
| } |
| // Not one of known proxies, nope: |
| return false; |
| } |
| |
| /** |
| * Helper method that checks if given class is a concrete one; |
| * that is, not an interface or abstract class. |
| */ |
| public static boolean isConcrete(Class<?> type) |
| { |
| int mod = type.getModifiers(); |
| return (mod & (Modifier.INTERFACE | Modifier.ABSTRACT)) == 0; |
| } |
| |
| /** |
| * @since 1.6 |
| */ |
| public static boolean isConcrete(Member member) |
| { |
| int mod = member.getModifiers(); |
| return (mod & (Modifier.INTERFACE | Modifier.ABSTRACT)) == 0; |
| } |
| |
| public static boolean isCollectionMapOrArray(Class<?> type) |
| { |
| if (type.isArray()) return true; |
| if (Collection.class.isAssignableFrom(type)) return true; |
| if (Map.class.isAssignableFrom(type)) return true; |
| return false; |
| } |
| |
| /* |
| /********************************************************** |
| /* Type name handling methods |
| /********************************************************** |
| */ |
| |
| /** |
| * Helper method used to construct appropriate description |
| * when passed either type (Class) or an instance; in latter |
| * case, class of instance is to be used. |
| */ |
| public static String getClassDescription(Object classOrInstance) |
| { |
| if (classOrInstance == null) { |
| return "unknown"; |
| } |
| Class<?> cls = (classOrInstance instanceof Class<?>) ? |
| (Class<?>) classOrInstance : classOrInstance.getClass(); |
| return cls.getName(); |
| } |
| |
| /* |
| /********************************************************** |
| /* Class loading |
| /********************************************************** |
| */ |
| |
| public static Class<?> findClass(String className) throws ClassNotFoundException |
| { |
| // [JACKSON-597]: support primitive types (and void) |
| if (className.indexOf('.') < 0) { |
| if ("int".equals(className)) return Integer.TYPE; |
| if ("long".equals(className)) return Long.TYPE; |
| if ("float".equals(className)) return Float.TYPE; |
| if ("double".equals(className)) return Double.TYPE; |
| if ("boolean".equals(className)) return Boolean.TYPE; |
| if ("byte".equals(className)) return Byte.TYPE; |
| if ("char".equals(className)) return Character.TYPE; |
| if ("short".equals(className)) return Short.TYPE; |
| if ("void".equals(className)) return Void.TYPE; |
| } |
| // Two-phase lookup: first using context ClassLoader; then default |
| Throwable prob = null; |
| ClassLoader loader = Thread.currentThread().getContextClassLoader(); |
| |
| if (loader != null) { |
| try { |
| return Class.forName(className, true, loader); |
| } catch (Exception e) { |
| prob = getRootCause(e); |
| } |
| } |
| try { |
| return Class.forName(className); |
| } catch (Exception e) { |
| if (prob == null) { |
| prob = getRootCause(e); |
| } |
| } |
| if (prob instanceof RuntimeException) { |
| throw (RuntimeException) prob; |
| } |
| throw new ClassNotFoundException(prob.getMessage(), prob); |
| } |
| |
| /* |
| /********************************************************** |
| /* Method type detection methods |
| /********************************************************** |
| */ |
| |
| public static boolean hasGetterSignature(Method m) |
| { |
| // First: static methods can't be getters |
| if (Modifier.isStatic(m.getModifiers())) { |
| return false; |
| } |
| // Must take no args |
| Class<?>[] pts = m.getParameterTypes(); |
| if (pts != null && pts.length != 0) { |
| return false; |
| } |
| // Can't be a void method |
| if (Void.TYPE == m.getReturnType()) { |
| return false; |
| } |
| // Otherwise looks ok: |
| return true; |
| } |
| |
| /* |
| /********************************************************** |
| /* Exception handling |
| /********************************************************** |
| */ |
| |
| /** |
| * Method that can be used to find the "root cause", innermost |
| * of chained (wrapped) exceptions. |
| */ |
| public static Throwable getRootCause(Throwable t) |
| { |
| while (t.getCause() != null) { |
| t = t.getCause(); |
| } |
| return t; |
| } |
| |
| /** |
| * Method that will unwrap root causes of given Throwable, and throw |
| * the innermost {@link Exception} or {@link Error} as is. |
| * This is useful in cases where mandatory wrapping is added, which |
| * is often done by Reflection API. |
| * |
| * @since 1.7 |
| */ |
| public static void throwRootCause(Throwable t) throws Exception |
| { |
| t = getRootCause(t); |
| if (t instanceof Exception) { |
| throw (Exception) t; |
| } |
| throw (Error) t; |
| } |
| |
| /** |
| * Method that will wrap 't' as an {@link IllegalArgumentException} if it |
| * is a checked exception; otherwise (runtime exception or error) throw as is |
| */ |
| public static void throwAsIAE(Throwable t) |
| { |
| throwAsIAE(t, t.getMessage()); |
| } |
| |
| /** |
| * Method that will wrap 't' as an {@link IllegalArgumentException} (and with |
| * specified message) if it |
| * is a checked exception; otherwise (runtime exception or error) throw as is |
| */ |
| public static void throwAsIAE(Throwable t, String msg) |
| { |
| if (t instanceof RuntimeException) { |
| throw (RuntimeException) t; |
| } |
| if (t instanceof Error) { |
| throw (Error) t; |
| } |
| throw new IllegalArgumentException(msg, t); |
| } |
| |
| /** |
| * Method that will locate the innermost exception for given Throwable; |
| * and then wrap it as an {@link IllegalArgumentException} if it |
| * is a checked exception; otherwise (runtime exception or error) throw as is |
| */ |
| public static void unwrapAndThrowAsIAE(Throwable t) |
| { |
| throwAsIAE(getRootCause(t)); |
| } |
| |
| /** |
| * Method that will locate the innermost exception for given Throwable; |
| * and then wrap it as an {@link IllegalArgumentException} if it |
| * is a checked exception; otherwise (runtime exception or error) throw as is |
| */ |
| public static void unwrapAndThrowAsIAE(Throwable t, String msg) |
| { |
| throwAsIAE(getRootCause(t), msg); |
| } |
| |
| /* |
| /********************************************************** |
| /* Instantiation |
| /********************************************************** |
| */ |
| |
| /** |
| * Method that can be called to try to create an instantiate of |
| * specified type. Instantiation is done using default no-argument |
| * constructor. |
| * |
| * @param canFixAccess Whether it is possible to try to change access |
| * rights of the default constructor (in case it is not publicly |
| * accessible) or not. |
| * |
| * @throws IllegalArgumentException If instantiation fails for any reason; |
| * except for cases where constructor throws an unchecked exception |
| * (which will be passed as is) |
| */ |
| public static <T> T createInstance(Class<T> cls, boolean canFixAccess) |
| throws IllegalArgumentException |
| { |
| Constructor<T> ctor = findConstructor(cls, canFixAccess); |
| if (ctor == null) { |
| throw new IllegalArgumentException("Class "+cls.getName()+" has no default (no arg) constructor"); |
| } |
| try { |
| return ctor.newInstance(); |
| } catch (Exception e) { |
| ClassUtil.unwrapAndThrowAsIAE(e, "Failed to instantiate class "+cls.getName()+", problem: "+e.getMessage()); |
| return null; |
| } |
| } |
| |
| public static <T> Constructor<T> findConstructor(Class<T> cls, boolean canFixAccess) |
| throws IllegalArgumentException |
| { |
| try { |
| Constructor<T> ctor = cls.getDeclaredConstructor(); |
| if (canFixAccess) { |
| checkAndFixAccess(ctor); |
| } else { |
| // Has to be public... |
| if (!Modifier.isPublic(ctor.getModifiers())) { |
| throw new IllegalArgumentException("Default constructor for "+cls.getName()+" is not accessible (non-public?): not allowed to try modify access via Reflection: can not instantiate type"); |
| } |
| } |
| return ctor; |
| } catch (NoSuchMethodException e) { |
| ; |
| } catch (Exception e) { |
| ClassUtil.unwrapAndThrowAsIAE(e, "Failed to find default constructor of class "+cls.getName()+", problem: "+e.getMessage()); |
| } |
| return null; |
| } |
| |
| /* |
| /********************************************************** |
| /* Primitive type support |
| /********************************************************** |
| */ |
| |
| /** |
| * Helper method used to get default value for wrappers used for primitive types |
| * (0 for Integer etc) |
| * |
| * @since 1.6.1 |
| */ |
| public static Object defaultValue(Class<?> cls) |
| { |
| if (cls == Integer.TYPE) { |
| return Integer.valueOf(0); |
| } |
| if (cls == Long.TYPE) { |
| return Long.valueOf(0L); |
| } |
| if (cls == Boolean.TYPE) { |
| return Boolean.FALSE; |
| } |
| if (cls == Double.TYPE) { |
| return Double.valueOf(0.0); |
| } |
| if (cls == Float.TYPE) { |
| return Float.valueOf(0.0f); |
| } |
| if (cls == Byte.TYPE) { |
| return Byte.valueOf((byte) 0); |
| } |
| if (cls == Short.TYPE) { |
| return Short.valueOf((short) 0); |
| } |
| if (cls == Character.TYPE) { |
| return '\0'; |
| } |
| throw new IllegalArgumentException("Class "+cls.getName()+" is not a primitive type"); |
| } |
| |
| /** |
| * Helper method for finding wrapper type for given primitive type (why isn't |
| * there one in JDK?) |
| * |
| * @since 1.7.1 |
| */ |
| public static Class<?> wrapperType(Class<?> primitiveType) |
| { |
| if (primitiveType == Integer.TYPE) { |
| return Integer.class; |
| } |
| if (primitiveType == Long.TYPE) { |
| return Long.class; |
| } |
| if (primitiveType == Boolean.TYPE) { |
| return Boolean.class; |
| } |
| if (primitiveType == Double.TYPE) { |
| return Double.class; |
| } |
| if (primitiveType == Float.TYPE) { |
| return Float.class; |
| } |
| if (primitiveType == Byte.TYPE) { |
| return Byte.class; |
| } |
| if (primitiveType == Short.TYPE) { |
| return Short.class; |
| } |
| if (primitiveType == Character.TYPE) { |
| return Character.class; |
| } |
| throw new IllegalArgumentException("Class "+primitiveType.getName()+" is not a primitive type"); |
| } |
| |
| /* |
| /********************************************************** |
| /* Access checking/handling methods |
| /********************************************************** |
| */ |
| |
| /** |
| * Method called to check if we can use the passed method or constructor |
| * (wrt access restriction -- public methods can be called, others |
| * usually not); and if not, if there is a work-around for |
| * the problem. |
| */ |
| public static void checkAndFixAccess(Member member) |
| { |
| // We know all members are also accessible objects... |
| AccessibleObject ao = (AccessibleObject) member; |
| |
| /* 14-Jan-2009, tatu: It seems safe and potentially beneficial to |
| * always to make it accessible (latter because it will force |
| * skipping checks we have no use for...), so let's always call it. |
| */ |
| //if (!ao.isAccessible()) { |
| try { |
| ao.setAccessible(true); |
| } catch (SecurityException se) { |
| /* 17-Apr-2009, tatu: Related to [JACKSON-101]: this can fail on |
| * platforms like EJB and Google App Engine); so let's |
| * only fail if we really needed it... |
| */ |
| if (!ao.isAccessible()) { |
| Class<?> declClass = member.getDeclaringClass(); |
| throw new IllegalArgumentException("Can not access "+member+" (from class "+declClass.getName()+"; failed to set access: "+se.getMessage()); |
| } |
| } |
| //} |
| } |
| |
| /* |
| /********************************************************** |
| /* Enum type detection |
| /********************************************************** |
| */ |
| |
| /** |
| * Helper method that can be used to dynamically figure out |
| * enumeration type of given {@link EnumSet}, without having |
| * access to its declaration. |
| * Code is needed to work around design flaw in JDK. |
| * |
| * @since 1.5 |
| */ |
| public static Class<? extends Enum<?>> findEnumType(EnumSet<?> s) |
| { |
| // First things first: if not empty, easy to determine |
| if (!s.isEmpty()) { |
| return findEnumType(s.iterator().next()); |
| } |
| // Otherwise need to locate using an internal field |
| return EnumTypeLocator.instance.enumTypeFor(s); |
| } |
| |
| /** |
| * Helper method that can be used to dynamically figure out |
| * enumeration type of given {@link EnumSet}, without having |
| * access to its declaration. |
| * Code is needed to work around design flaw in JDK. |
| * |
| * @since 1.5 |
| */ |
| public static Class<? extends Enum<?>> findEnumType(EnumMap<?,?> m) |
| { |
| if (!m.isEmpty()) { |
| return findEnumType(m.keySet().iterator().next()); |
| } |
| // Otherwise need to locate using an internal field |
| return EnumTypeLocator.instance.enumTypeFor(m); |
| } |
| |
| /** |
| * Helper method that can be used to dynamically figure out formal |
| * enumeration type (class) for given enumeration. This is either |
| * class of enum instance (for "simple" enumerations), or its |
| * superclass (for enums with instance fields or methods) |
| */ |
| @SuppressWarnings("unchecked") |
| public static Class<? extends Enum<?>> findEnumType(Enum<?> en) |
| { |
| // enums with "body" are sub-classes of the formal type |
| Class<?> ec = en.getClass(); |
| if (ec.getSuperclass() != Enum.class) { |
| ec = ec.getSuperclass(); |
| } |
| return (Class<? extends Enum<?>>) ec; |
| } |
| |
| /** |
| * Helper method that can be used to dynamically figure out formal |
| * enumeration type (class) for given class of an enumeration value. |
| * This is either class of enum instance (for "simple" enumerations), |
| * or its superclass (for enums with instance fields or methods) |
| */ |
| @SuppressWarnings("unchecked") |
| public static Class<? extends Enum<?>> findEnumType(Class<?> cls) |
| { |
| // enums with "body" are sub-classes of the formal type |
| if (cls.getSuperclass() != Enum.class) { |
| cls = cls.getSuperclass(); |
| } |
| return (Class<? extends Enum<?>>) cls; |
| } |
| |
| /* |
| /********************************************************** |
| /* Helper classes |
| /********************************************************** |
| */ |
| |
| /** |
| * Inner class used to contain gory details of how we can determine |
| * details of instances of common JDK types like {@link EnumMap}s. |
| */ |
| private static class EnumTypeLocator |
| { |
| final static EnumTypeLocator instance = new EnumTypeLocator(); |
| |
| private final Field enumSetTypeField; |
| private final Field enumMapTypeField; |
| |
| private EnumTypeLocator() { |
| /* JDK uses following fields to store information about actual Enumeration |
| * type for EnumSets, EnumMaps... |
| */ |
| enumSetTypeField = locateField(EnumSet.class, "elementType", Class.class); |
| enumMapTypeField = locateField(EnumMap.class, "elementType", Class.class); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public Class<? extends Enum<?>> enumTypeFor(EnumSet<?> set) |
| { |
| if (enumSetTypeField != null) { |
| return (Class<? extends Enum<?>>) get(set, enumSetTypeField); |
| } |
| throw new IllegalStateException("Can not figure out type for EnumSet (odd JDK platform?)"); |
| } |
| |
| @SuppressWarnings("unchecked") |
| public Class<? extends Enum<?>> enumTypeFor(EnumMap<?,?> set) |
| { |
| if (enumMapTypeField != null) { |
| return (Class<? extends Enum<?>>) get(set, enumMapTypeField); |
| } |
| throw new IllegalStateException("Can not figure out type for EnumMap (odd JDK platform?)"); |
| |
| } |
| |
| private Object get(Object bean, Field field) |
| { |
| try { |
| return field.get(bean); |
| } catch (Exception e) { |
| throw new IllegalArgumentException(e); |
| } |
| } |
| |
| private static Field locateField(Class<?> fromClass, String expectedName, Class<?> type) |
| { |
| Field found = null; |
| // First: let's see if we can find exact match: |
| Field[] fields = fromClass.getDeclaredFields(); |
| for (Field f : fields) { |
| if (expectedName.equals(f.getName()) && f.getType() == type) { |
| found = f; |
| break; |
| } |
| } |
| // And if not, if there is just one field with the type, that field |
| if (found == null) { |
| for (Field f : fields) { |
| if (f.getType() == type) { |
| // If more than one, can't choose |
| if (found != null) return null; |
| found = f; |
| } |
| } |
| } |
| if (found != null) { // it's non-public, need to force accessible |
| try { |
| found.setAccessible(true); |
| } catch (Throwable t) { } |
| } |
| return found; |
| } |
| } |
| } |
