net.sf.cglib.beans.BeanMap Maven / Gradle / Ivy
/*
* Copyright 2003,2004 The Apache Software Foundation
*
* 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 net.sf.cglib.beans;
import java.beans.*;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.*;
import net.sf.cglib.core.*;
import org.objectweb.asm.ClassVisitor;
/**
* A Map-based view of a JavaBean. The default set of keys is the
* union of all property names (getters or setters). An attempt to set
* a read-only property will be ignored, and write-only properties will
* be returned as null. Removal of objects is not a
* supported (the key set is fixed).
* @author Chris Nokleberg
*/
abstract public class BeanMap implements Map {
/**
* Limit the properties reflected in the key set of the map
* to readable properties.
* @see BeanMap.Generator#setRequire
*/
public static final int REQUIRE_GETTER = 1;
/**
* Limit the properties reflected in the key set of the map
* to writable properties.
* @see BeanMap.Generator#setRequire
*/
public static final int REQUIRE_SETTER = 2;
/**
* Helper method to create a new BeanMap. For finer
* control over the generated instance, use a new instance of
* BeanMap.Generator instead of this static method.
* @param bean the JavaBean underlying the map
* @return a new BeanMap instance
*/
public static BeanMap create(Object bean) {
Generator gen = new Generator();
gen.setBean(bean);
return gen.create();
}
public static class Generator extends AbstractClassGenerator {
private static final Source SOURCE = new Source(BeanMap.class.getName());
private static final BeanMapKey KEY_FACTORY =
(BeanMapKey)KeyFactory.create(BeanMapKey.class, KeyFactory.CLASS_BY_NAME);
interface BeanMapKey {
public Object newInstance(Class type, int require);
}
private Object bean;
private Class beanClass;
private int require;
public Generator() {
super(SOURCE);
}
/**
* Set the bean that the generated map should reflect. The bean may be swapped
* out for another bean of the same type using {@link #setBean}.
* Calling this method overrides any value previously set using {@link #setBeanClass}.
* You must call either this method or {@link #setBeanClass} before {@link #create}.
* @param bean the initial bean
*/
public void setBean(Object bean) {
this.bean = bean;
if (bean != null)
beanClass = bean.getClass();
}
/**
* Set the class of the bean that the generated map should support.
* You must call either this method or {@link #setBeanClass} before {@link #create}.
* @param beanClass the class of the bean
*/
public void setBeanClass(Class beanClass) {
this.beanClass = beanClass;
}
/**
* Limit the properties reflected by the generated map.
* @param require any combination of {@link #REQUIRE_GETTER} and
* {@link #REQUIRE_SETTER}; default is zero (any property allowed)
*/
public void setRequire(int require) {
this.require = require;
}
protected ClassLoader getDefaultClassLoader() {
return beanClass.getClassLoader();
}
/**
* Create a new instance of the BeanMap. An existing
* generated class will be reused if possible.
*/
public BeanMap create() {
if (beanClass == null)
throw new IllegalArgumentException("Class of bean unknown");
setNamePrefix(beanClass.getName());
return (BeanMap)super.create(KEY_FACTORY.newInstance(beanClass, require));
}
public void generateClass(ClassVisitor v) throws Exception {
new BeanMapEmitter(v, getClassName(), beanClass, require);
}
protected Object firstInstance(Class type) {
return ((BeanMap)ReflectUtils.newInstance(type)).newInstance(bean);
}
protected Object nextInstance(Object instance) {
return ((BeanMap)instance).newInstance(bean);
}
}
/**
* Create a new BeanMap instance using the specified bean.
* This is faster than using the {@link #create} static method.
* @param bean the JavaBean underlying the map
* @return a new BeanMap instance
*/
abstract public BeanMap newInstance(Object bean);
/**
* Get the type of a property.
* @param name the name of the JavaBean property
* @return the type of the property, or null if the property does not exist
*/
abstract public Class getPropertyType(String name);
protected Object bean;
protected BeanMap() {
}
protected BeanMap(Object bean) {
setBean(bean);
}
public Object get(Object key) {
return get(bean, key);
}
public Object put(Object key, Object value) {
return put(bean, key, value);
}
/**
* Get the property of a bean. This allows a BeanMap
* to be used statically for multiple beans--the bean instance tied to the
* map is ignored and the bean passed to this method is used instead.
* @param bean the bean to query; must be compatible with the type of
* this BeanMap
* @param key must be a String
* @return the current value, or null if there is no matching property
*/
abstract public Object get(Object bean, Object key);
/**
* Set the property of a bean. This allows a BeanMap
* to be used statically for multiple beans--the bean instance tied to the
* map is ignored and the bean passed to this method is used instead.
* @param key must be a String
* @return the old value, if there was one, or null
*/
abstract public Object put(Object bean, Object key, Object value);
/**
* Change the underlying bean this map should use.
* @param bean the new JavaBean
* @see #getBean
*/
public void setBean(Object bean) {
this.bean = bean;
}
/**
* Return the bean currently in use by this map.
* @return the current JavaBean
* @see #setBean
*/
public Object getBean() {
return bean;
}
public void clear() {
throw new UnsupportedOperationException();
}
public boolean containsKey(Object key) {
return keySet().contains(key);
}
public boolean containsValue(Object value) {
for (Iterator it = keySet().iterator(); it.hasNext();) {
Object v = get(it.next());
if (((value == null) && (v == null)) || value.equals(v))
return true;
}
return false;
}
public int size() {
return keySet().size();
}
public boolean isEmpty() {
return size() == 0;
}
public Object remove(Object key) {
throw new UnsupportedOperationException();
}
public void putAll(Map t) {
for (Iterator it = t.keySet().iterator(); it.hasNext();) {
Object key = it.next();
put(key, t.get(key));
}
}
public boolean equals(Object o) {
if (o == null || !(o instanceof Map)) {
return false;
}
Map other = (Map)o;
if (size() != other.size()) {
return false;
}
for (Iterator it = keySet().iterator(); it.hasNext();) {
Object key = it.next();
if (!other.containsKey(key)) {
return false;
}
Object v1 = get(key);
Object v2 = other.get(key);
if (!((v1 == null) ? v2 == null : v1.equals(v2))) {
return false;
}
}
return true;
}
public int hashCode() {
int code = 0;
for (Iterator it = keySet().iterator(); it.hasNext();) {
Object key = it.next();
Object value = get(key);
code += ((key == null) ? 0 : key.hashCode()) ^
((value == null) ? 0 : value.hashCode());
}
return code;
}
// TODO: optimize
public Set entrySet() {
HashMap copy = new HashMap();
for (Iterator it = keySet().iterator(); it.hasNext();) {
Object key = it.next();
copy.put(key, get(key));
}
return Collections.unmodifiableMap(copy).entrySet();
}
public Collection values() {
Set keys = keySet();
List values = new ArrayList(keys.size());
for (Iterator it = keys.iterator(); it.hasNext();) {
values.add(get(it.next()));
}
return Collections.unmodifiableCollection(values);
}
/*
* @see java.util.AbstractMap#toString
*/
public String toString()
{
StringBuffer sb = new StringBuffer();
sb.append('{');
for (Iterator it = keySet().iterator(); it.hasNext();) {
Object key = it.next();
sb.append(key);
sb.append('=');
sb.append(get(key));
if (it.hasNext()) {
sb.append(", ");
}
}
sb.append('}');
return sb.toString();
}
}