com.sun.xml.bind.v2.model.nav.ReflectionNavigator Maven / Gradle / Ivy
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/*
* Copyright (c) 1997, 2021 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0, which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
package com.sun.xml.bind.v2.model.nav;
import java.lang.reflect.Array;
import java.lang.reflect.Field;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.GenericDeclaration;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.lang.reflect.WildcardType;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Arrays;
import java.util.Collection;
import com.sun.xml.bind.v2.runtime.Location;
/**
* {@link Navigator} implementation for {@code java.lang.reflect}.
*
*/
/*package*/final class ReflectionNavigator implements Navigator {
// ---------- Singleton -----------------
private static final ReflectionNavigator INSTANCE = new ReflectionNavigator();
/*package*/static ReflectionNavigator getInstance() {
return INSTANCE;
}
private ReflectionNavigator() {
}
// ---------------------------------------
public Class getSuperClass(Class clazz) {
if (clazz == Object.class) {
return null;
}
Class sc = clazz.getSuperclass();
if (sc == null) {
sc = Object.class; // error recovery
}
return sc;
}
private static final TypeVisitor baseClassFinder = new TypeVisitor() {
public Type onClass(Class c, Class sup) {
// t is a raw type
if (sup == c) {
return sup;
}
Type r;
Type sc = c.getGenericSuperclass();
if (sc != null) {
r = visit(sc, sup);
if (r != null) {
return r;
}
}
for (Type i : c.getGenericInterfaces()) {
r = visit(i, sup);
if (r != null) {
return r;
}
}
return null;
}
public Type onParameterizdType(ParameterizedType p, Class sup) {
Class raw = (Class) p.getRawType();
if (raw == sup) {
// p is of the form sup<...>
return p;
} else {
// recursively visit super class/interfaces
Type r = raw.getGenericSuperclass();
if (r != null) {
r = visit(bind(r, raw, p), sup);
}
if (r != null) {
return r;
}
for (Type i : raw.getGenericInterfaces()) {
r = visit(bind(i, raw, p), sup);
if (r != null) {
return r;
}
}
return null;
}
}
public Type onGenericArray(GenericArrayType g, Class sup) {
// not clear what I should do here
return null;
}
public Type onVariable(TypeVariable v, Class sup) {
return visit(v.getBounds()[0], sup);
}
public Type onWildcard(WildcardType w, Class sup) {
// not clear what I should do here
return null;
}
/**
* Replaces the type variables in {@code t} by its actual arguments.
*
* @param decl
* provides a list of type variables. See {@link GenericDeclaration#getTypeParameters()}
* @param args
* actual arguments. See {@link ParameterizedType#getActualTypeArguments()}
*/
private Type bind(Type t, GenericDeclaration decl, ParameterizedType args) {
return binder.visit(t, new BinderArg(decl, args.getActualTypeArguments()));
}
};
private static class BinderArg {
final TypeVariable[] params;
final Type[] args;
BinderArg(TypeVariable[] params, Type[] args) {
this.params = params;
this.args = args;
assert params.length == args.length;
}
public BinderArg(GenericDeclaration decl, Type[] args) {
this(decl.getTypeParameters(), args);
}
Type replace(TypeVariable v) {
for (int i = 0; i < params.length; i++) {
if (params[i].equals(v)) {
return args[i];
}
}
return v; // this is a free variable
}
}
private static final TypeVisitor binder = new TypeVisitor() {
public Type onClass(Class c, BinderArg args) {
return c;
}
public Type onParameterizdType(ParameterizedType p, BinderArg args) {
Type[] params = p.getActualTypeArguments();
boolean different = false;
for (int i = 0; i < params.length; i++) {
Type t = params[i];
params[i] = visit(t, args);
different |= t != params[i];
}
Type newOwner = p.getOwnerType();
if (newOwner != null) {
newOwner = visit(newOwner, args);
}
different |= p.getOwnerType() != newOwner;
if (!different) {
return p;
}
return new ParameterizedTypeImpl((Class) p.getRawType(), params, newOwner);
}
public Type onGenericArray(GenericArrayType g, BinderArg types) {
Type c = visit(g.getGenericComponentType(), types);
if (c == g.getGenericComponentType()) {
return g;
}
return new GenericArrayTypeImpl(c);
}
public Type onVariable(TypeVariable v, BinderArg types) {
return types.replace(v);
}
public Type onWildcard(WildcardType w, BinderArg types) {
// TODO: this is probably still incorrect
// bind( "? extends T" ) with T= "? extends Foo" should be "? extends Foo",
// not "? extends (? extends Foo)"
Type[] lb = w.getLowerBounds();
Type[] ub = w.getUpperBounds();
boolean diff = false;
for (int i = 0; i < lb.length; i++) {
Type t = lb[i];
lb[i] = visit(t, types);
diff |= (t != lb[i]);
}
for (int i = 0; i < ub.length; i++) {
Type t = ub[i];
ub[i] = visit(t, types);
diff |= (t != ub[i]);
}
if (!diff) {
return w;
}
return new WildcardTypeImpl(lb, ub);
}
};
public Type getBaseClass(Type t, Class sup) {
return baseClassFinder.visit(t, sup);
}
public String getClassName(Class clazz) {
return clazz.getName();
}
public String getTypeName(Type type) {
if (type instanceof Class) {
Class c = (Class) type;
if (c.isArray()) {
return getTypeName(c.getComponentType()) + "[]";
}
return c.getName();
}
return type.toString();
}
public String getClassShortName(Class clazz) {
return clazz.getSimpleName();
}
public Collection getDeclaredFields(final Class clazz) {
Field[] fields = AccessController.doPrivileged(new PrivilegedAction() {
@Override
public Field[] run() {
return clazz.getDeclaredFields();
}
});
return Arrays.asList(fields);
}
public Field getDeclaredField(final Class clazz, final String fieldName) {
return AccessController.doPrivileged(new PrivilegedAction() {
@Override
public Field run() {
try {
return clazz.getDeclaredField(fieldName);
} catch (NoSuchFieldException e) {
return null;
}
}
});
}
public Collection getDeclaredMethods(final Class clazz) {
Method[] methods =
AccessController.doPrivileged(new PrivilegedAction() {
@Override
public Method[] run() {
return clazz.getDeclaredMethods();
}
});
return Arrays.asList(methods);
}
public Class getDeclaringClassForField(Field field) {
return field.getDeclaringClass();
}
public Class getDeclaringClassForMethod(Method method) {
return method.getDeclaringClass();
}
public Type getFieldType(Field field) {
if (field.getType().isArray()) {
Class c = field.getType().getComponentType();
if (c.isPrimitive()) {
return Array.newInstance(c, 0).getClass();
}
}
return fix(field.getGenericType());
}
public String getFieldName(Field field) {
return field.getName();
}
public String getMethodName(Method method) {
return method.getName();
}
public Type getReturnType(Method method) {
return fix(method.getGenericReturnType());
}
public Type[] getMethodParameters(Method method) {
return method.getGenericParameterTypes();
}
public boolean isStaticMethod(Method method) {
return Modifier.isStatic(method.getModifiers());
}
public boolean isFinalMethod(Method method) {
return Modifier.isFinal(method.getModifiers());
}
public boolean isSubClassOf(Type sub, Type sup) {
return erasure(sup).isAssignableFrom(erasure(sub));
}
public Class ref(Class c) {
return c;
}
public Class use(Class c) {
return c;
}
public Class asDecl(Type t) {
return erasure(t);
}
public Class asDecl(Class c) {
return c;
}
/**
* Implements the logic for {@link #erasure(Type)}.
*/
private static final TypeVisitor eraser = new TypeVisitor() {
public Class onClass(Class c, Void v) {
return c;
}
public Class onParameterizdType(ParameterizedType p, Void v) {
// TODO: why getRawType returns Type? not Class?
return visit(p.getRawType(), null);
}
public Class onGenericArray(GenericArrayType g, Void v) {
return Array.newInstance(
visit(g.getGenericComponentType(), null),
0).getClass();
}
public Class onVariable(TypeVariable tv, Void v) {
return visit(tv.getBounds()[0], null);
}
public Class onWildcard(WildcardType w, Void v) {
return visit(w.getUpperBounds()[0], null);
}
};
/**
* Returns the runtime representation of the given type.
*
* This corresponds to the notion of the erasure in JSR-14.
*
*
* Because of the difference in the way Annotation Processing and the Java reflection
* treats primitive type and array type, we can't define this method
* on {@link Navigator}.
*
*
* It made me realize how difficult it is to define the common navigation
* layer for two different underlying reflection library. The other way
* is to throw away the entire parameterization and go to the wrapper approach.
*/
public Class erasure(Type t) {
return eraser.visit(t, null);
}
public boolean isAbstract(Class clazz) {
return Modifier.isAbstract(clazz.getModifiers());
}
public boolean isFinal(Class clazz) {
return Modifier.isFinal(clazz.getModifiers());
}
/**
* Returns the {@link Type} object that represents {@code clazz}.
*/
public Type createParameterizedType(Class rawType, Type... arguments) {
return new ParameterizedTypeImpl(rawType, arguments, null);
}
public boolean isArray(Type t) {
if (t instanceof Class) {
Class c = (Class) t;
return c.isArray();
}
if (t instanceof GenericArrayType) {
return true;
}
return false;
}
public boolean isArrayButNotByteArray(Type t) {
if (t instanceof Class) {
Class c = (Class) t;
return c.isArray() && c != byte[].class;
}
if (t instanceof GenericArrayType) {
t = ((GenericArrayType) t).getGenericComponentType();
return t != Byte.TYPE;
}
return false;
}
public Type getComponentType(Type t) {
if (t instanceof Class) {
Class c = (Class) t;
return c.getComponentType();
}
if (t instanceof GenericArrayType) {
return ((GenericArrayType) t).getGenericComponentType();
}
throw new IllegalArgumentException();
}
public Type getTypeArgument(Type type, int i) {
if (type instanceof ParameterizedType) {
ParameterizedType p = (ParameterizedType) type;
return fix(p.getActualTypeArguments()[i]);
} else {
throw new IllegalArgumentException();
}
}
public boolean isParameterizedType(Type type) {
return type instanceof ParameterizedType;
}
public boolean isPrimitive(Type type) {
if (type instanceof Class) {
Class c = (Class) type;
return c.isPrimitive();
}
return false;
}
public Type getPrimitive(Class primitiveType) {
assert primitiveType.isPrimitive();
return primitiveType;
}
public Location getClassLocation(final Class clazz) {
return new Location() {
@Override
public String toString() {
return clazz.getName();
}
};
}
public Location getFieldLocation(final Field field) {
return new Location() {
@Override
public String toString() {
return field.toString();
}
};
}
public Location getMethodLocation(final Method method) {
return new Location() {
@Override
public String toString() {
return method.toString();
}
};
}
public boolean hasDefaultConstructor(Class c) {
try {
c.getDeclaredConstructor();
return true;
} catch (NoSuchMethodException e) {
return false; // todo: do this WITHOUT exception throw
}
}
public boolean isStaticField(Field field) {
return Modifier.isStatic(field.getModifiers());
}
public boolean isPublicMethod(Method method) {
return Modifier.isPublic(method.getModifiers());
}
public boolean isPublicField(Field field) {
return Modifier.isPublic(field.getModifiers());
}
public boolean isEnum(Class c) {
return Enum.class.isAssignableFrom(c);
}
public Field[] getEnumConstants(Class clazz) {
try {
Object[] values = clazz.getEnumConstants();
Field[] fields = new Field[values.length];
for (int i = 0; i < values.length; i++) {
fields[i] = clazz.getField(((Enum) values[i]).name());
}
return fields;
} catch (NoSuchFieldException e) {
// impossible
throw new NoSuchFieldError(e.getMessage());
}
}
public Type getVoidType() {
return Void.class;
}
public String getPackageName(Class clazz) {
String name = clazz.getName();
int idx = name.lastIndexOf('.');
if (idx < 0) {
return "";
} else {
return name.substring(0, idx);
}
}
@Override
public Class loadObjectFactory(Class referencePoint, String pkg) {
ClassLoader cl = SecureLoader.getClassClassLoader(referencePoint);
if (cl == null)
cl = SecureLoader.getSystemClassLoader();
try {
return cl.loadClass(pkg + ".ObjectFactory");
} catch (ClassNotFoundException e) {
return null;
}
}
public boolean isBridgeMethod(Method method) {
return method.isBridge();
}
public boolean isOverriding(Method method, final Class base) {
// this isn't actually correct,
// as the JLS considers
// class Derived extends Base {
// Integer getX() { ... }
// }
// class Base {
// T getX() { ... }
// }
// to be overrided. Handling this correctly needs a careful implementation
final String name = method.getName();
final Class[] params = method.getParameterTypes();
return AccessController.doPrivileged(
new PrivilegedAction() {
@Override
public Boolean run() {
Class clazz = base;
while (clazz != null) {
try {
Method m = clazz.getDeclaredMethod(name, params);
if (m != null) {
return Boolean.TRUE;
}
} catch (NoSuchMethodException ignored) {
// recursively go into the base class
}
clazz = clazz.getSuperclass();
}
return Boolean.FALSE;
}
}
);
}
public boolean isInterface(Class clazz) {
return clazz.isInterface();
}
public boolean isTransient(Field f) {
return Modifier.isTransient(f.getModifiers());
}
public boolean isInnerClass(Class clazz) {
return clazz.getEnclosingClass() != null && !Modifier.isStatic(clazz.getModifiers());
}
@Override
public boolean isSameType(Type t1, Type t2) {
return t1.equals(t2);
}
/**
* JDK 5.0 has a bug of creating {@link GenericArrayType} where it shouldn't.
* fix that manually to work around the problem.
*
* See bug 6202725.
*/
private Type fix(Type t) {
if (!(t instanceof GenericArrayType)) {
return t;
}
GenericArrayType gat = (GenericArrayType) t;
if (gat.getGenericComponentType() instanceof Class) {
Class c = (Class) gat.getGenericComponentType();
return Array.newInstance(c, 0).getClass();
}
return t;
}
}