org.constretto.internal.MethodParameter Maven / Gradle / Ivy
/*
* Copyright 2002-2010 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.
*/
package org.constretto.internal;
import java.lang.annotation.Annotation;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.util.HashMap;
import java.util.Map;
/**
* Helper class that encapsulates the specification of a method parameter, i.e.
* a Method or Constructor plus a parameter index and a nested type index for
* a declared generic type. Useful as a specification object to pass along.
*
* @author Juergen Hoeller
* @author Rob Harrop
* @author Andy Clement
* @see GenericCollectionTypeResolver
* @since 2.0
*/
public class MethodParameter {
private Method method;
private Constructor constructor;
private final int parameterIndex;
private Class parameterType;
private Annotation[] parameterAnnotations;
private int nestingLevel = 1;
/**
* Map from Integer level to Integer type index
*/
private Map typeIndexesPerLevel;
Map typeVariableMap;
/**
* Create a new MethodParameter for the given method, with nesting level 1.
*
* @param method the Method to specify a parameter for
* @param parameterIndex the index of the parameter
*/
public MethodParameter(Method method, int parameterIndex) {
this(method, parameterIndex, 1);
}
/**
* Create a new MethodParameter for the given method.
*
* @param method the Method to specify a parameter for
* @param parameterIndex the index of the parameter
* (-1 for the method return type; 0 for the first method parameter,
* 1 for the second method parameter, etc)
* @param nestingLevel the nesting level of the target type
* (typically 1; e.g. in case of a List of Lists, 1 would indicate the
* nested List, whereas 2 would indicate the element of the nested List)
*/
public MethodParameter(Method method, int parameterIndex, int nestingLevel) {
this.method = method;
this.parameterIndex = parameterIndex;
this.nestingLevel = nestingLevel;
}
/**
* Create a new MethodParameter for the given constructor, with nesting level 1.
*
* @param constructor the Constructor to specify a parameter for
* @param parameterIndex the index of the parameter
*/
public MethodParameter(Constructor constructor, int parameterIndex) {
this(constructor, parameterIndex, 1);
}
/**
* Create a new MethodParameter for the given constructor.
*
* @param constructor the Constructor to specify a parameter for
* @param parameterIndex the index of the parameter
* @param nestingLevel the nesting level of the target type
* (typically 1; e.g. in case of a List of Lists, 1 would indicate the
* nested List, whereas 2 would indicate the element of the nested List)
*/
public MethodParameter(Constructor constructor, int parameterIndex, int nestingLevel) {
if (constructor == null) {
throw new NullPointerException("Constructor must not be null");
}
this.constructor = constructor;
this.parameterIndex = parameterIndex;
this.nestingLevel = nestingLevel;
}
/**
* Return the wrapped Method, if any.
* Note: Either Method or Constructor is available.
*
* @return the Method, or null if none
*/
public Method getMethod() {
return this.method;
}
/**
* Return the wrapped Constructor, if any.
*
Note: Either Method or Constructor is available.
*
* @return the Constructor, or null if none
*/
public Constructor getConstructor() {
return this.constructor;
}
/**
* Return the class that declares the underlying Method or Constructor.
*/
public Class getDeclaringClass() {
return (this.method != null ? this.method.getDeclaringClass() : this.constructor.getDeclaringClass());
}
/**
* Return the index of the method/constructor parameter.
*
* @return the parameter index (never negative)
*/
public int getParameterIndex() {
return this.parameterIndex;
}
/**
* Set a resolved (generic) parameter type.
*/
void setParameterType(Class parameterType) {
this.parameterType = parameterType;
}
/**
* Return the type of the method/constructor parameter.
*
* @return the parameter type (never null)
*/
public Class getParameterType() {
if (this.parameterType == null) {
if (this.parameterIndex < 0) {
this.parameterType = (this.method != null ? this.method.getReturnType() : null);
} else {
this.parameterType = (this.method != null ?
this.method.getParameterTypes()[this.parameterIndex] :
this.constructor.getParameterTypes()[this.parameterIndex]);
}
}
return this.parameterType;
}
/**
* Return the annotations associated with the target method/constructor itself.
*/
public Annotation[] getMethodAnnotations() {
return (this.method != null ? this.method.getAnnotations() : this.constructor.getAnnotations());
}
/**
* Return the annotations associated with the specific method/constructor parameter.
*/
public Annotation[] getParameterAnnotations() {
if (this.parameterAnnotations == null) {
Annotation[][] annotationArray = (this.method != null ?
this.method.getParameterAnnotations() : this.constructor.getParameterAnnotations());
if (this.parameterIndex >= 0 && this.parameterIndex < annotationArray.length) {
this.parameterAnnotations = annotationArray[this.parameterIndex];
} else {
this.parameterAnnotations = new Annotation[0];
}
}
return this.parameterAnnotations;
}
/**
* Return the nesting level of the target type
* (typically 1; e.g. in case of a List of Lists, 1 would indicate the
* nested List, whereas 2 would indicate the element of the nested List).
*/
public int getNestingLevel() {
return this.nestingLevel;
}
/**
* Return the type index for the specified nesting level.
*
* @param nestingLevel the nesting level to check
* @return the corresponding type index, or null
* if none specified (indicating the default type index)
*/
public Integer getTypeIndexForLevel(int nestingLevel) {
return getTypeIndexesPerLevel().get(nestingLevel);
}
/**
* Obtain the (lazily constructed) type-indexes-per-level Map.
*/
private Map getTypeIndexesPerLevel() {
if (this.typeIndexesPerLevel == null) {
this.typeIndexesPerLevel = new HashMap(4);
}
return this.typeIndexesPerLevel;
}
}