com.facebook.presto.jdbc.internal.jackson.databind.util.ClassUtil Maven / Gradle / Ivy
package com.facebook.presto.jdbc.internal.jackson.databind.util;
import java.io.Closeable;
import java.io.IOException;
import java.lang.annotation.Annotation;
import java.lang.reflect.*;
import java.util.*;
import com.facebook.presto.jdbc.internal.jackson.core.JsonGenerator;
import com.facebook.presto.jdbc.internal.jackson.core.JsonProcessingException;
import com.facebook.presto.jdbc.internal.jackson.databind.DeserializationContext;
import com.facebook.presto.jdbc.internal.jackson.databind.JavaType;
import com.facebook.presto.jdbc.internal.jackson.databind.JsonMappingException;
import com.facebook.presto.jdbc.internal.jackson.databind.annotation.JacksonStdImpl;
public final class ClassUtil
{
private final static Class CLS_OBJECT = Object.class;
private final static Annotation[] NO_ANNOTATIONS = new Annotation[0];
private final static Ctor[] NO_CTORS = new Ctor[0];
private final static Iterator EMPTY_ITERATOR = Collections.emptyIterator();
/*
/**********************************************************
/* Simple factory methods
/**********************************************************
*/
/**
* @since 2.7
*/
@SuppressWarnings("unchecked")
public static Iterator emptyIterator() {
return (Iterator) EMPTY_ITERATOR;
}
/*
/**********************************************************
/* 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 Object.class is not included in the list
* regardless of whether endBefore 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).
*
* @since 2.7
*/
public static List findSuperTypes(JavaType type, Class endBefore,
boolean addClassItself) {
if ((type == null) || type.hasRawClass(endBefore) || type.hasRawClass(Object.class)) {
return Collections.emptyList();
}
List result = new ArrayList(8);
_addSuperTypes(type, endBefore, result, addClassItself);
return result;
}
/**
* @since 2.7
*/
public static List> findRawSuperTypes(Class cls, Class endBefore, boolean addClassItself) {
if ((cls == null) || (cls == endBefore) || (cls == Object.class)) {
return Collections.emptyList();
}
List> result = new ArrayList>(8);
_addRawSuperTypes(cls, endBefore, result, addClassItself);
return result;
}
/**
* Method for finding all super classes (but not super interfaces) of given class,
* starting with the immediate super class and ending in the most distant one.
* Class itself is included if addClassItself is true.
*
* NOTE: mostly/only called to resolve mix-ins as that's where we do not care
* about fully-resolved types, just associated annotations.
*
* @since 2.7
*/
public static List> findSuperClasses(Class cls, Class endBefore,
boolean addClassItself) {
List> result = new ArrayList>(8);
if ((cls != null) && (cls != endBefore)) {
if (addClassItself) {
result.add(cls);
}
while ((cls = cls.getSuperclass()) != null) {
if (cls == endBefore) {
break;
}
result.add(cls);
}
}
return result;
}
@Deprecated // since 2.7
public static List> findSuperTypes(Class cls, Class endBefore) {
return findSuperTypes(cls, endBefore, new ArrayList>(8));
}
@Deprecated // since 2.7
public static List> findSuperTypes(Class cls, Class endBefore, List> result) {
_addRawSuperTypes(cls, endBefore, result, false);
return result;
}
private static void _addSuperTypes(JavaType type, Class endBefore, Collection result,
boolean addClassItself)
{
if (type == null) {
return;
}
final Class cls = type.getRawClass();
if (cls == endBefore || cls == Object.class) { return; }
if (addClassItself) {
if (result.contains(type)) { // already added, no need to check supers
return;
}
result.add(type);
}
for (JavaType intCls : type.getInterfaces()) {
_addSuperTypes(intCls, endBefore, result, true);
}
_addSuperTypes(type.getSuperClass(), endBefore, result, true);
}
private static void _addRawSuperTypes(Class cls, Class endBefore, Collection> 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 : _interfaces(cls)) {
_addRawSuperTypes(intCls, endBefore, result, true);
}
_addRawSuperTypes(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;
}
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 (hasEnclosingMethod(type)) {
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 (!Modifier.isStatic(type.getModifiers())) {
if (getEnclosingClass(type) != null) {
return "non-static member class";
}
}
}
}
catch (SecurityException e) { }
catch (NullPointerException e) { }
return null;
}
/**
* Method for finding enclosing class for non-static inner classes
*/
public static Class getOuterClass(Class type)
{
// as above, GAE has some issues...
try {
// one more: method locals, anonymous, are not good:
if (hasEnclosingMethod(type)) {
return null;
}
if (!Modifier.isStatic(type.getModifiers())) {
return getEnclosingClass(type);
}
} catch (SecurityException 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 [databind#57], should NOT disqualify JDK proxy:
/*
// Then: well-known proxy (etc) classes
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;
}
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;
}
public static boolean isBogusClass(Class cls) {
return (cls == Void.class || cls == Void.TYPE
|| cls == com.facebook.presto.jdbc.internal.jackson.databind.annotation.NoClass.class);
}
public static boolean isNonStaticInnerClass(Class cls) {
return !Modifier.isStatic(cls.getModifiers())
&& (getEnclosingClass(cls) != null);
}
/**
* @since 2.7
*/
public static boolean isObjectOrPrimitive(Class cls) {
return (cls == CLS_OBJECT) || cls.isPrimitive();
}
/**
* @since 2.9
*/
public static boolean hasClass(Object inst, Class raw) {
// 10-Nov-2016, tatu: Could use `Class.isInstance()` if we didn't care
// about being exactly that type
return (inst != null) && (inst.getClass() == raw);
}
/**
* @since 2.9
*/
public static void verifyMustOverride(Class expType, Object instance,
String method)
{
if (instance.getClass() != expType) {
throw new IllegalStateException(String.format(
"Sub-class %s (of class %s) must override method '%s'",
instance.getClass().getName(), expType.getName(), method));
}
}
/*
/**********************************************************
/* Method type detection methods
/**********************************************************
*/
/**
* @deprecated Since 2.6 not used; may be removed before 3.x
*/
@Deprecated // since 2.6
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; simple re-throw
/**********************************************************
*/
/**
* Helper method that will check if argument is an {@link Error},
* and if so, (re)throw it; otherwise just return
*
* @since 2.9
*/
public static Throwable throwIfError(Throwable t) {
if (t instanceof Error) {
throw (Error) t;
}
return t;
}
/**
* Helper method that will check if argument is an {@link RuntimeException},
* and if so, (re)throw it; otherwise just return
*
* @since 2.9
*/
public static Throwable throwIfRTE(Throwable t) {
if (t instanceof RuntimeException) {
throw (RuntimeException) t;
}
return t;
}
/**
* Helper method that will check if argument is an {@link IOException},
* and if so, (re)throw it; otherwise just return
*
* @since 2.9
*/
public static Throwable throwIfIOE(Throwable t) throws IOException {
if (t instanceof IOException) {
throw (IOException) t;
}
return t;
}
/*
/**********************************************************
/* Exception handling; other
/**********************************************************
*/
/**
* 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 works like by calling {@link #getRootCause} and then
* either throwing it (if instanceof {@link IOException}), or
* return.
*
* @since 2.8
*/
public static Throwable throwRootCauseIfIOE(Throwable t) throws IOException {
return throwIfIOE(getRootCause(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)
{
throwIfRTE(t);
throwIfError(t);
throw new IllegalArgumentException(msg, t);
}
/**
* @since 2.9
*/
public static T throwAsMappingException(DeserializationContext ctxt,
IOException e0) throws JsonMappingException {
if (e0 instanceof JsonMappingException) {
throw (JsonMappingException) e0;
}
JsonMappingException e = JsonMappingException.from(ctxt, e0.getMessage());
e.initCause(e0);
throw e;
}
/**
* 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);
}
/**
* Helper method that encapsulate logic in trying to close output generator
* in case of failure; useful mostly in forcing flush()ing as otherwise
* error conditions tend to be hard to diagnose. However, it is often the
* case that output state may be corrupt so we need to be prepared for
* secondary exception without masking original one.
*
* @since 2.8
*/
public static void closeOnFailAndThrowAsIOE(JsonGenerator g, Exception fail)
throws IOException
{
/* 04-Mar-2014, tatu: Let's try to prevent auto-closing of
* structures, which typically causes more damage.
*/
g.disable(JsonGenerator.Feature.AUTO_CLOSE_JSON_CONTENT);
try {
g.close();
} catch (Exception e) {
fail.addSuppressed(e);
}
throwIfIOE(fail);
throwIfRTE(fail);
throw new RuntimeException(fail);
}
/**
* Helper method that encapsulate logic in trying to close given {@link Closeable}
* in case of failure; useful mostly in forcing flush()ing as otherwise
* error conditions tend to be hard to diagnose. However, it is often the
* case that output state may be corrupt so we need to be prepared for
* secondary exception without masking original one.
*
* @since 2.8
*/
public static void closeOnFailAndThrowAsIOE(JsonGenerator g,
Closeable toClose, Exception fail)
throws IOException
{
if (g != null) {
g.disable(JsonGenerator.Feature.AUTO_CLOSE_JSON_CONTENT);
try {
g.close();
} catch (Exception e) {
fail.addSuppressed(e);
}
}
if (toClose != null) {
try {
toClose.close();
} catch (Exception e) {
fail.addSuppressed(e);
}
}
throwIfIOE(fail);
throwIfRTE(fail);
throw new RuntimeException(fail);
}
/*
/**********************************************************
/* 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 createInstance(Class cls, boolean canFixAccess)
throws IllegalArgumentException
{
Constructor 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 Constructor findConstructor(Class cls, boolean forceAccess)
throws IllegalArgumentException
{
try {
Constructor ctor = cls.getDeclaredConstructor();
if (forceAccess) {
checkAndFixAccess(ctor, forceAccess);
} 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: cannot 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;
}
/*
/**********************************************************
/* Class name, description access
/**********************************************************
*/
/**
* @since 2.9
*/
public static Class classOf(Object inst) {
if (inst == null) {
return null;
}
return inst.getClass();
}
/**
* @since 2.9
*/
public static Class rawClass(JavaType t) {
if (t == null) {
return null;
}
return t.getRawClass();
}
/**
* @since 2.9
*/
public static T nonNull(T valueOrNull, T defaultValue) {
return (valueOrNull == null) ? defaultValue : valueOrNull;
}
/**
* @since 2.9
*/
public static String nullOrToString(Object value) {
if (value == null) {
return null;
}
return value.toString();
}
/**
* @since 2.9
*/
public static String nonNullString(String str) {
if (str == null) {
return "";
}
return str;
}
/**
* Returns either quoted value (with double-quotes) -- if argument non-null
* String -- or String NULL (no quotes) (if null).
*
* @since 2.9
*/
public static String quotedOr(Object str, String forNull) {
if (str == null) {
return forNull;
}
return String.format("\"%s\"", str);
}
/*
/**********************************************************
/* Type name, name, desc 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 nameOf(cls);
}
/**
* Helper method to create and return "backticked" description of given
* resolved type (or, {@code "null"} if {@code null} passed), similar
* to return vaue of {@link #getClassDescription(Object)}.
*
* @param fullType Fully resolved type or null
* @return String description of type including generic type parameters, surrounded
* by backticks, if type passed; or string "null" if {code null} passed
*
* @since 2.10
*/
public static String getTypeDescription(JavaType fullType)
{
if (fullType == null) {
return "[null]";
}
StringBuilder sb = new StringBuilder(80).append('`');
sb.append(fullType.toCanonical());
return sb.append('`').toString();
}
/**
* 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.
*
* @since 2.9
*/
public static String classNameOf(Object inst) {
if (inst == null) {
return "[null]";
}
Class raw = (inst instanceof Class) ? (Class) inst : inst.getClass();
return nameOf(raw);
}
/**
* Returns either `cls.getName()` (if `cls` not null),
* or "[null]" if `cls` is null.
*
* @since 2.9
*/
public static String nameOf(Class cls) {
if (cls == null) {
return "[null]";
}
int index = 0;
while (cls.isArray()) {
++index;
cls = cls.getComponentType();
}
String base = cls.isPrimitive() ? cls.getSimpleName() : cls.getName();
if (index > 0) {
StringBuilder sb = new StringBuilder(base);
do {
sb.append("[]");
} while (--index > 0);
base = sb.toString();
}
return backticked(base);
}
/**
* Returns either backtick-quoted `named.getName()` (if `named` not null),
* or "[null]" if `named` is null.
*
* @since 2.9
*/
public static String nameOf(Named named) {
if (named == null) {
return "[null]";
}
return backticked(named.getName());
}
/*
/**********************************************************
/* Other escaping, description access
/**********************************************************
*/
/**
* Returns either `text` or [null].
*
* @since 2.9
*/
public static String backticked(String text) {
if (text == null) {
return "[null]";
}
return new StringBuilder(text.length()+2).append('`').append(text).append('`').toString();
}
/**
* Helper method that returns {@link Throwable#getMessage()} for all other exceptions
* except for {@link JsonProcessingException}, for which {@code getOriginalMessage()} is
* returned instead.
* Method is used to avoid accidentally including trailing location information twice
* in message when wrapping exceptions.
*
* @since 2.9.7
*/
public static String exceptionMessage(Throwable t) {
if (t instanceof JsonProcessingException) {
return ((JsonProcessingException) t).getOriginalMessage();
}
return t.getMessage();
}
/*
/**********************************************************
/* Primitive type support
/**********************************************************
*/
/**
* Helper method used to get default value for wrappers used for primitive types
* (0 for Integer etc)
*/
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?)
*/
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");
}
/**
* Method that can be used to find primitive type for given class if (but only if)
* it is either wrapper type or primitive type; returns `null` if type is neither.
*
* @since 2.7
*/
public static Class primitiveType(Class type)
{
if (type.isPrimitive()) {
return type;
}
if (type == Integer.class) {
return Integer.TYPE;
}
if (type == Long.class) {
return Long.TYPE;
}
if (type == Boolean.class) {
return Boolean.TYPE;
}
if (type == Double.class) {
return Double.TYPE;
}
if (type == Float.class) {
return Float.TYPE;
}
if (type == Byte.class) {
return Byte.TYPE;
}
if (type == Short.class) {
return Short.TYPE;
}
if (type == Character.class) {
return Character.TYPE;
}
return null;
}
/*
/**********************************************************
/* Access checking/handling methods
/**********************************************************
*/
/**
* Equivalent to call:
*
* checkAndFixAccess(member, false);
*
*
* @deprecated Since 2.7 call variant that takes boolean flag.
*/
@Deprecated
public static void checkAndFixAccess(Member member) {
checkAndFixAccess(member, false);
}
/**
* Method that is called if a {@link Member} may need forced access,
* to force a field, method or constructor to be accessible: this
* is done by calling {@link AccessibleObject#setAccessible(boolean)}.
*
* @param member Accessor to call setAccessible() on.
* @param force Whether to always try to make accessor accessible (true),
* or only if needed as per access rights (false)
*
* @since 2.7
*/
public static void checkAndFixAccess(Member member, boolean force)
{
// 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.
*/
try {
if (force ||
(!Modifier.isPublic(member.getModifiers())
|| !Modifier.isPublic(member.getDeclaringClass().getModifiers()))) {
ao.setAccessible(true);
}
} catch (SecurityException se) {
// 17-Apr-2009, tatu: Related to [JACKSON-101]: this can fail on platforms like
// Google App Engine); so let's only fail if we really needed it...
if (!ao.isAccessible()) {
Class declClass = member.getDeclaringClass();
throw new IllegalArgumentException("Cannot 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.
*/
public static Class> 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.
*/
public static Class> 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> 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>) 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> findEnumType(Class cls)
{
// enums with "body" are sub-classes of the formal type
if (cls.getSuperclass() != Enum.class) {
cls = cls.getSuperclass();
}
return (Class>) cls;
}
/**
* A method that will look for the first Enum value annotated with the given Annotation.
*
* If there's more than one value annotated, the first one found will be returned. Which one exactly is used is undetermined.
*
* @param enumClass The Enum class to scan for a value with the given annotation
* @param annotationClass The annotation to look for.
* @return the Enum value annotated with the given Annotation or {@code null} if none is found.
* @throws IllegalArgumentException if there's a reflection issue accessing the Enum
* @since 2.8
*/
public static Enum findFirstAnnotatedEnumValue(Class> enumClass, Class annotationClass)
{
Field[] fields = getDeclaredFields(enumClass);
for (Field field : fields) {
if (field.isEnumConstant()) {
Annotation defaultValueAnnotation = field.getAnnotation(annotationClass);
if (defaultValueAnnotation != null) {
final String name = field.getName();
for (Enum enumValue : enumClass.getEnumConstants()) {
if (name.equals(enumValue.name())) {
return enumValue;
}
}
}
}
}
return null;
}
/*
/**********************************************************
/* Jackson-specific stuff
/**********************************************************
*/
/**
* Method that can be called to determine if given Object is the default
* implementation Jackson uses; as opposed to a custom serializer installed by
* a module or calling application. Determination is done using
* {@link JacksonStdImpl} annotation on handler (serializer, deserializer etc)
* class.
*
* NOTE: passing `null` is legal, and will result in true
* being returned.
*/
public static boolean isJacksonStdImpl(Object impl) {
return (impl == null) || isJacksonStdImpl(impl.getClass());
}
public static boolean isJacksonStdImpl(Class implClass) {
return (implClass.getAnnotation(JacksonStdImpl.class) != null);
}
/*
/**********************************************************
/* Access to various Class definition aspects; possibly
/* cacheable; and attempts was made in 2.7.0 - 2.7.7; however
/* unintented retention (~= memory leak) wrt [databind#1363]
/* resulted in removal of caching
/**********************************************************
*/
/**
* @since 2.7
*/
public static String getPackageName(Class cls) {
Package pkg = cls.getPackage();
return (pkg == null) ? null : pkg.getName();
}
/**
* @since 2.7
*/
public static boolean hasEnclosingMethod(Class cls) {
return !isObjectOrPrimitive(cls) && (cls.getEnclosingMethod() != null);
}
/**
* @since 2.7
*/
public static Field[] getDeclaredFields(Class cls) {
return cls.getDeclaredFields();
}
/**
* @since 2.7
*/
public static Method[] getDeclaredMethods(Class cls) {
return cls.getDeclaredMethods();
}
/**
* @since 2.7
*/
public static Annotation[] findClassAnnotations(Class cls) {
if (isObjectOrPrimitive(cls)) {
return NO_ANNOTATIONS;
}
return cls.getDeclaredAnnotations();
}
/**
* Helper method that gets methods declared in given class; usually a simple thing,
* but sometimes (as per [databind#785]) more complicated, depending on classloader
* setup.
*
* @since 2.9
*/
public static Method[] getClassMethods(Class cls)
{
try {
return ClassUtil.getDeclaredMethods(cls);
} catch (final NoClassDefFoundError ex) {
// One of the methods had a class that was not found in the cls.getClassLoader.
// Maybe the developer was nice and has a different class loader for this context.
final ClassLoader loader = Thread.currentThread().getContextClassLoader();
if (loader == null){
// Nope... this is going to end poorly
throw ex;
}
final Class contextClass;
try {
contextClass = loader.loadClass(cls.getName());
} catch (ClassNotFoundException e) {
ex.addSuppressed(e);
throw ex;
}
return contextClass.getDeclaredMethods(); // Cross fingers
}
}
/**
* @since 2.7
*/
public static Ctor[] getConstructors(Class cls) {
// Note: can NOT skip abstract classes as they may be used with mix-ins
// and for regular use shouldn't really matter.
if (cls.isInterface() || isObjectOrPrimitive(cls)) {
return NO_CTORS;
}
Constructor[] rawCtors = cls.getDeclaredConstructors();
final int len = rawCtors.length;
Ctor[] result = new Ctor[len];
for (int i = 0; i < len; ++i) {
result[i] = new Ctor(rawCtors[i]);
}
return result;
}
// // // Then methods that do NOT cache access but were considered
// // // (and could be added to do caching if it was proven effective)
/**
* @since 2.7
*/
public static Class getDeclaringClass(Class cls) {
return isObjectOrPrimitive(cls) ? null : cls.getDeclaringClass();
}
/**
* @since 2.7
*/
public static Type getGenericSuperclass(Class cls) {
return cls.getGenericSuperclass();
}
/**
* @since 2.7
*/
public static Type[] getGenericInterfaces(Class cls) {
return cls.getGenericInterfaces();
}
/**
* @since 2.7
*/
public static Class getEnclosingClass(Class cls) {
// Caching does not seem worthwhile, as per profiling
return isObjectOrPrimitive(cls) ? null : cls.getEnclosingClass();
}
private static Class[] _interfaces(Class cls) {
return cls.getInterfaces();
}
/*
/**********************************************************
/* 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> enumTypeFor(EnumSet set)
{
if (enumSetTypeField != null) {
return (Class>) get(set, enumSetTypeField);
}
throw new IllegalStateException("Cannot figure out type for EnumSet (odd JDK platform?)");
}
@SuppressWarnings("unchecked")
public Class> enumTypeFor(EnumMap set)
{
if (enumMapTypeField != null) {
return (Class>) get(set, enumMapTypeField);
}
throw new IllegalStateException("Cannot 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 = getDeclaredFields(fromClass);
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;
}
}
/*
/**********************************************************
/* Helper classed used for caching
/**********************************************************
*/
/**
* Value class used for caching Constructor declarations; used because
* caching done by JDK appears to be somewhat inefficient for some use cases.
*
* @since 2.7
*/
public final static class Ctor
{
public final Constructor _ctor;
private Annotation[] _annotations;
private Annotation[][] _paramAnnotations;
private int _paramCount = -1;
public Ctor(Constructor ctor) {
_ctor = ctor;
}
public Constructor getConstructor() {
return _ctor;
}
public int getParamCount() {
int c = _paramCount;
if (c < 0) {
c = _ctor.getParameterTypes().length;
_paramCount = c;
}
return c;
}
public Class getDeclaringClass() {
return _ctor.getDeclaringClass();
}
public Annotation[] getDeclaredAnnotations() {
Annotation[] result = _annotations;
if (result == null) {
result = _ctor.getDeclaredAnnotations();
_annotations = result;
}
return result;
}
public Annotation[][] getParameterAnnotations() {
Annotation[][] result = _paramAnnotations;
if (result == null) {
result = _ctor.getParameterAnnotations();
_paramAnnotations = result;
}
return result;
}
}
}