Mega Code Archive
If right-hand side type may be assigned to the left-hand side type following the Java generics rules
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/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import java.beans.Introspector;
import java.lang.reflect.Array;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Proxy;
import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import junit.framework.Assert;
import sun.rmi.runtime.Log;
/**
* Utility to work with Java 5 generic type parameters.
* Mainly for internal use within the framework.
*
* @author Ramnivas Laddad
* @author Juergen Hoeller
* @since 2.0.7
*/
public abstract class TypeUtils {
/**
* Check if the right-hand side type may be assigned to the left-hand side
* type following the Java generics rules.
* @param lhsType the target type
* @param rhsType the value type that should be assigned to the target type
* @return true if rhs is assignable to lhs
*/
public static boolean isAssignable(Type lhsType, Type rhsType) {
if (lhsType.equals(rhsType)) {
return true;
}
if (lhsType instanceof Class && rhsType instanceof Class) {
return ClassUtils.isAssignable((Class) lhsType, (Class) rhsType);
}
if (lhsType instanceof ParameterizedType && rhsType instanceof ParameterizedType) {
return isAssignable((ParameterizedType) lhsType, (ParameterizedType) rhsType);
}
if (lhsType instanceof WildcardType) {
return isAssignable((WildcardType) lhsType, rhsType);
}
return false;
}
private static boolean isAssignable(ParameterizedType lhsType, ParameterizedType rhsType) {
if (lhsType.equals(rhsType)) {
return true;
}
Type[] lhsTypeArguments = lhsType.getActualTypeArguments();
Type[] rhsTypeArguments = rhsType.getActualTypeArguments();
if (lhsTypeArguments.length != rhsTypeArguments.length) {
return false;
}
for (int size = lhsTypeArguments.length, i = 0; i < size; ++i) {
Type lhsArg = lhsTypeArguments[i];
Type rhsArg = rhsTypeArguments[i];
if (!lhsArg.equals(rhsArg) &&
!(lhsArg instanceof WildcardType && isAssignable((WildcardType) lhsArg, rhsArg))) {
return false;
}
}
return true;
}
private static boolean isAssignable(WildcardType lhsType, Type rhsType) {
Type[] upperBounds = lhsType.getUpperBounds();
Type[] lowerBounds = lhsType.getLowerBounds();
for (int size = upperBounds.length, i = 0; i < size; ++i) {
if (!isAssignable(upperBounds[i], rhsType)) {
return false;
}
}
for (int size = lowerBounds.length, i = 0; i < size; ++i) {
if (!isAssignable(rhsType, lowerBounds[i])) {
return false;
}
}
return true;
}
}
/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* Miscellaneous class utility methods. Mainly for internal use within the
* framework; consider Jakarta's Commons Lang for a more comprehensive suite
* of class utilities.
*
* @author Keith Donald
* @author Rob Harrop
* @author Juergen Hoeller
* @since 1.1
* @see TypeUtils
* @see ReflectionUtils
*/
abstract class ClassUtils {
/** Suffix for array class names: "[]" */
public static final String ARRAY_SUFFIX = "[]";
/** Prefix for internal array class names: "[L" */
private static final String INTERNAL_ARRAY_PREFIX = "[L";
/** The package separator character '.' */
private static final char PACKAGE_SEPARATOR = '.';
/** The inner class separator character '$' */
private static final char INNER_CLASS_SEPARATOR = '$';
/** The CGLIB class separator character "$$" */
public static final String CGLIB_CLASS_SEPARATOR = "$$";
/** The ".class" file suffix */
public static final String CLASS_FILE_SUFFIX = ".class";
/**
* Map with primitive wrapper type as key and corresponding primitive
* type as value, for example: Integer.class -> int.class.
*/
private static final Map primitiveWrapperTypeMap = new HashMap(8);
/**
* Map with primitive type name as key and corresponding primitive
* type as value, for example: "int" -> "int.class".
*/
private static final Map primitiveTypeNameMap = new HashMap(16);
static {
primitiveWrapperTypeMap.put(Boolean.class, boolean.class);
primitiveWrapperTypeMap.put(Byte.class, byte.class);
primitiveWrapperTypeMap.put(Character.class, char.class);
primitiveWrapperTypeMap.put(Double.class, double.class);
primitiveWrapperTypeMap.put(Float.class, float.class);
primitiveWrapperTypeMap.put(Integer.class, int.class);
primitiveWrapperTypeMap.put(Long.class, long.class);
primitiveWrapperTypeMap.put(Short.class, short.class);
Set primitiveTypeNames = new HashSet(16);
primitiveTypeNames.addAll(primitiveWrapperTypeMap.values());
primitiveTypeNames.addAll(Arrays.asList(new Class[] {
boolean[].class, byte[].class, char[].class, double[].class,
float[].class, int[].class, long[].class, short[].class}));
for (Iterator it = primitiveTypeNames.iterator(); it.hasNext();) {
Class primitiveClass = (Class) it.next();
primitiveTypeNameMap.put(primitiveClass.getName(), primitiveClass);
}
}
/**
* Check if the right-hand side type may be assigned to the left-hand side
* type, assuming setting by reflection. Considers primitive wrapper
* classes as assignable to the corresponding primitive types.
* @param lhsType the target type
* @param rhsType the value type that should be assigned to the target type
* @return if the target type is assignable from the value type
* @see TypeUtils#isAssignable
*/
public static boolean isAssignable(Class lhsType, Class rhsType) {
return (lhsType.isAssignableFrom(rhsType) ||
lhsType.equals(primitiveWrapperTypeMap.get(rhsType)));
}
}
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