package org.springframework.util;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import org.springframework.lang.Nullable;
public abstract class TypeUtils {
public static boolean isAssignable(Type lhsType, Type rhsType) {
Assert.notNull(lhsType, "Left-hand side type must not be null");
Assert.notNull(rhsType, "Right-hand side type must not be null");
if (lhsType.equals(rhsType) || Object.class == lhsType) {
return true;
}
if (lhsType instanceof Class) {
Class<?> lhsClass = (Class<?>) lhsType;
if (rhsType instanceof Class) {
return ClassUtils.isAssignable(lhsClass, (Class<?>) rhsType);
}
if (rhsType instanceof ParameterizedType) {
Type rhsRaw = ((ParameterizedType) rhsType).getRawType();
if (rhsRaw instanceof Class) {
return ClassUtils.isAssignable(lhsClass, (Class<?>) rhsRaw);
}
}
else if (lhsClass.isArray() && rhsType instanceof GenericArrayType) {
Type rhsComponent = ((GenericArrayType) rhsType).getGenericComponentType();
return isAssignable(lhsClass.getComponentType(), rhsComponent);
}
}
if (lhsType instanceof ParameterizedType) {
if (rhsType instanceof Class) {
Type lhsRaw = ((ParameterizedType) lhsType).getRawType();
if (lhsRaw instanceof Class) {
return ClassUtils.isAssignable((Class<?>) lhsRaw, (Class<?>) rhsType);
}
}
else if (rhsType instanceof ParameterizedType) {
return isAssignable((ParameterizedType) lhsType, (ParameterizedType) rhsType);
}
}
if (lhsType instanceof GenericArrayType) {
Type lhsComponent = ((GenericArrayType) lhsType).getGenericComponentType();
if (rhsType instanceof Class) {
Class<?> rhsClass = (Class<?>) rhsType;
if (rhsClass.isArray()) {
return isAssignable(lhsComponent, rhsClass.getComponentType());
}
}
else if (rhsType instanceof GenericArrayType) {
Type rhsComponent = ((GenericArrayType) rhsType).getGenericComponentType();
return isAssignable(lhsComponent, rhsComponent);
}
}
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[] lUpperBounds = lhsType.getUpperBounds();
if (lUpperBounds.length == 0) {
lUpperBounds = new Type[] { Object.class };
}
Type[] lLowerBounds = lhsType.getLowerBounds();
if (lLowerBounds.length == 0) {
lLowerBounds = new Type[] { null };
}
if (rhsType instanceof WildcardType) {
WildcardType rhsWcType = (WildcardType) rhsType;
Type[] rUpperBounds = rhsWcType.getUpperBounds();
if (rUpperBounds.length == 0) {
rUpperBounds = new Type[] { Object.class };
}
Type[] rLowerBounds = rhsWcType.getLowerBounds();
if (rLowerBounds.length == 0) {
rLowerBounds = new Type[] { null };
}
for (Type lBound : lUpperBounds) {
for (Type rBound : rUpperBounds) {
if (!isAssignableBound(lBound, rBound)) {
return false;
}
}
for (Type rBound : rLowerBounds) {
if (!isAssignableBound(lBound, rBound)) {
return false;
}
}
}
for (Type lBound : lLowerBounds) {
for (Type rBound : rUpperBounds) {
if (!isAssignableBound(rBound, lBound)) {
return false;
}
}
for (Type rBound : rLowerBounds) {
if (!isAssignableBound(rBound, lBound)) {
return false;
}
}
}
}
else {
for (Type lBound : lUpperBounds) {
if (!isAssignableBound(lBound, rhsType)) {
return false;
}
}
for (Type lBound : lLowerBounds) {
if (!isAssignableBound(rhsType, lBound)) {
return false;
}
}
}
return true;
}
public static boolean isAssignableBound(@Nullable Type lhsType, @Nullable Type rhsType) {
if (rhsType == null) {
return true;
}
if (lhsType == null) {
return false;
}
return isAssignable(lhsType, rhsType);
}
}