/*
* Copyright 2002-2018 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
*
* https://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.
*/
package org.springframework.expression;
import org.springframework.core.convert.TypeDescriptor;
import org.springframework.lang.Nullable;
import org.springframework.util.ObjectUtils;
Encapsulates an object and a TypeDescriptor
that describes it. The type descriptor can contain generic declarations that would not be accessible through a simple getClass()
call on the object. Author: Andy Clement, Juergen Hoeller Since: 3.0
/**
* Encapsulates an object and a {@link TypeDescriptor} that describes it.
* The type descriptor can contain generic declarations that would not
* be accessible through a simple {@code getClass()} call on the object.
*
* @author Andy Clement
* @author Juergen Hoeller
* @since 3.0
*/
public class TypedValue {
TypedValue
for null
. /**
* {@link TypedValue} for {@code null}.
*/
public static final TypedValue NULL = new TypedValue(null);
@Nullable
private final Object value;
@Nullable
private TypeDescriptor typeDescriptor;
Create a TypedValue
for a simple object. The TypeDescriptor
is inferred from the object, so no generic declarations are preserved. Params: - value – the object value
/**
* Create a {@link TypedValue} for a simple object. The {@link TypeDescriptor}
* is inferred from the object, so no generic declarations are preserved.
* @param value the object value
*/
public TypedValue(@Nullable Object value) {
this.value = value;
this.typeDescriptor = null; // initialized when/if requested
}
Create a TypedValue
for a particular value with a particular TypeDescriptor
which may contain additional generic declarations. Params: - value – the object value
- typeDescriptor – a type descriptor describing the type of the value
/**
* Create a {@link TypedValue} for a particular value with a particular
* {@link TypeDescriptor} which may contain additional generic declarations.
* @param value the object value
* @param typeDescriptor a type descriptor describing the type of the value
*/
public TypedValue(@Nullable Object value, @Nullable TypeDescriptor typeDescriptor) {
this.value = value;
this.typeDescriptor = typeDescriptor;
}
@Nullable
public Object getValue() {
return this.value;
}
@Nullable
public TypeDescriptor getTypeDescriptor() {
if (this.typeDescriptor == null && this.value != null) {
this.typeDescriptor = TypeDescriptor.forObject(this.value);
}
return this.typeDescriptor;
}
@Override
public boolean equals(@Nullable Object other) {
if (this == other) {
return true;
}
if (!(other instanceof TypedValue)) {
return false;
}
TypedValue otherTv = (TypedValue) other;
// Avoid TypeDescriptor initialization if not necessary
return (ObjectUtils.nullSafeEquals(this.value, otherTv.value) &&
((this.typeDescriptor == null && otherTv.typeDescriptor == null) ||
ObjectUtils.nullSafeEquals(getTypeDescriptor(), otherTv.getTypeDescriptor())));
}
@Override
public int hashCode() {
return ObjectUtils.nullSafeHashCode(this.value);
}
@Override
public String toString() {
return "TypedValue: '" + this.value + "' of [" + getTypeDescriptor() + "]";
}
}