/*
* Copyright 2001-2004 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 com.querydsl.core.util;
import java.beans.BeanInfo;
import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.*;
import com.google.common.base.Function;
import com.google.common.primitives.Primitives;
/**
* An implementation of Map for JavaBeans which uses introspection to
* get and put properties in the bean.
* <p>
* If an exception occurs during attempts to get or set a property then the
* property is considered non existent in the Map
* <p>
*
* @author James Strachan
* @author Matt Hall, John Watkinson, Stephen Colebourne
* @version $Revision: 1.1 $ $Date: 2005/10/11 17:05:19 $
* @since Commons Collections 1.0
*/
@SuppressWarnings("rawtypes")
public class BeanMap extends AbstractMap<String, Object> implements Cloneable {
private transient Object bean;
private transient Map<String, Method> readMethods = new HashMap<String, Method>();
private transient Map<String, Method> writeMethods = new HashMap<String, Method>();
private transient Map<String, Class<?>> types = new HashMap<String, Class<?>>();
/**
* An empty array. Used to invoke accessors via reflection.
*/
private static final Object[] NULL_ARGUMENTS = {};
/**
* Maps primitive Class types to transformers. The transformer
* transform strings into the appropriate primitive wrapper.
*/
private static final Map<Class<?>, Function<?,?>> defaultFunctions = new HashMap<Class<?>, Function<?,?>>();
static {
defaultFunctions.put(Boolean.TYPE, new Function() {
@Override
public Object apply(Object input) {
return Boolean.valueOf(input.toString());
}
});
defaultFunctions.put(Character.TYPE, new Function() {
@Override
public Object apply(Object input) {
return input.toString().charAt(0);
}
});
defaultFunctions.put(Byte.TYPE, new Function() {
@Override
public Object apply(Object input) {
return Byte.valueOf(input.toString());
}
});
defaultFunctions.put(Short.TYPE, new Function() {
@Override
public Object apply(Object input) {
return Short.valueOf(input.toString());
}
});
defaultFunctions.put(Integer.TYPE, new Function() {
@Override
public Object apply(Object input) {
return Integer.valueOf(input.toString());
}
});
defaultFunctions.put(Long.TYPE, new Function() {
@Override
public Object apply(Object input) {
return Long.valueOf(input.toString());
}
});
defaultFunctions.put(Float.TYPE, new Function() {
@Override
public Object apply(Object input) {
return Float.valueOf(input.toString());
}
});
defaultFunctions.put(Double.TYPE, new Function() {
@Override
public Object apply(Object input) {
return Double.valueOf(input.toString());
}
});
}
// Constructors
//-------------------------------------------------------------------------
/**
* Constructs a new empty {@code BeanMap}.
*/
public BeanMap() {
}
/**
* Constructs a new {@code BeanMap} that operates on the
* specified bean. If the given bean is {@code null}, then
* this map will be empty.
*
* @param bean the bean for this map to operate on
*/
public BeanMap(Object bean) {
this.bean = bean;
initialise();
}
// Map interface
//-------------------------------------------------------------------------
@Override
public String toString() {
return "BeanMap<" + bean + ">";
}
/**
* Clone this bean map using the following process:
* <p>
* <ul>
* <li>If there is no underlying bean, return a cloned BeanMap without a
* bean.
* <p>
* <li>Since there is an underlying bean, try to instantiate a new bean of
* the same type using Class.newInstance().
* <p>
* <li>If the instantiation fails, throw a CloneNotSupportedException
* <p>
* <li>Clone the bean map and set the newly instantiated bean as the
* underlying bean for the bean map.
* <p>
* <li>Copy each property that is both readable and writable from the
* existing object to a cloned bean map.
* <p>
* <li>If anything fails along the way, throw a
* CloneNotSupportedException.
* <p>
* </ul>
*/
@Override
public Object clone() throws CloneNotSupportedException {
BeanMap newMap = (BeanMap) super.clone();
if (bean == null) {
// no bean, just an empty bean map at the moment. return a newly
// cloned and empty bean map.
return newMap;
}
Object newBean = null;
Class<?> beanClass = null;
try {
beanClass = bean.getClass();
newBean = beanClass.newInstance();
} catch (Exception e) {
// unable to instantiate
throw new CloneNotSupportedException("Unable to instantiate the underlying bean \"" + beanClass.getName() + "\": " + e);
}
try {
newMap.setBean(newBean);
} catch (Exception exception) {
throw new CloneNotSupportedException("Unable to set bean in the cloned bean map: " + exception);
}
try {
// copy only properties that are readable and writable. If its
// not readable, we can't get the value from the old map. If
// its not writable, we can't write a value into the new map.
Iterator<String> readableKeys = readMethods.keySet().iterator();
while (readableKeys.hasNext()) {
String key = readableKeys.next();
if (getWriteMethod(key) != null) {
newMap.put(key, get(key));
}
}
} catch (Exception exception) {
throw new CloneNotSupportedException("Unable to copy bean values to cloned bean map: " + exception);
}
return newMap;
}
/**
* Puts all of the writable properties from the given BeanMap into this
* BeanMap. Read-only and Write-only properties will be ignored.
*
* @param map the BeanMap whose properties to put
*/
public void putAllWriteable(BeanMap map) {
Iterator<String> readableKeys = map.readMethods.keySet().iterator();
while (readableKeys.hasNext()) {
String key = readableKeys.next();
if (getWriteMethod(key) != null) {
this.put(key, map.get(key));
}
}
}
/**
* This method reinitializes the bean map to have default values for the
* bean's properties. This is accomplished by constructing a new instance
* of the bean which the map uses as its underlying data source. This
* behavior for {@link Map#clear() clear()} differs from the Map contract in that
* the mappings are not actually removed from the map (the mappings for a
* BeanMap are fixed).
*/
@Override
public void clear() {
if (bean == null) {
return;
}
Class<?> beanClass = null;
try {
beanClass = bean.getClass();
bean = beanClass.newInstance();
} catch (Exception e) {
throw new UnsupportedOperationException("Could not create new instance of class: " + beanClass);
}
}
/**
* Returns true if the bean defines a property with the given name.
* <p>
* The given name must be a {@code String}; if not, this method
* returns false. This method will also return false if the bean
* does not define a property with that name.
* <p>
* Write-only properties will not be matched as the test operates against
* property read methods.
*
* @param name the name of the property to check
* @return false if the given name is null or is not a {@code String};
* false if the bean does not define a property with that name; or
* true if the bean does define a property with that name
*/
public boolean containsKey(String name) {
Method method = getReadMethod(name);
return method != null;
}
/**
* Returns the value of the bean's property with the given name.
* <p>
* The given name must be a {@link String} and must not be
* null; otherwise, this method returns {@code null}.
* If the bean defines a property with the given name, the value of
* that property is returned. Otherwise, {@code null} is
* returned.
* <p>
* Write-only properties will not be matched as the test operates against
* property read methods.
*
* @param name the name of the property whose value to return
* @return the value of the property with that name
*/
public Object get(String name) {
if (bean != null) {
Method method = getReadMethod(name);
if (method != null) {
try {
return method.invoke(bean, NULL_ARGUMENTS);
} catch (IllegalAccessException e) {
} catch (IllegalArgumentException e) {
} catch (InvocationTargetException e) {
} catch (NullPointerException e) {
}
}
}
return null;
}
/**
* Sets the bean property with the given name to the given value.
*
* @param name the name of the property to set
* @param value the value to set that property to
* @return the previous value of that property
*/
@Override
public Object put(String name, Object value) {
if (bean != null) {
Object oldValue = get(name);
Method method = getWriteMethod(name);
if (method == null) {
throw new IllegalArgumentException("The bean of type: " + bean.getClass().getName() + " has no property called: " + name);
}
try {
Object[] arguments = createWriteMethodArguments(method, value);
method.invoke(bean, arguments);
Object newValue = get(name);
firePropertyChange(name, oldValue, newValue);
} catch (InvocationTargetException e) {
throw new IllegalArgumentException(e.getMessage());
} catch (IllegalAccessException e) {
throw new IllegalArgumentException(e.getMessage());
}
return oldValue;
}
return null;
}
/**
* Returns the number of properties defined by the bean.
*
* @return the number of properties defined by the bean
*/
@Override
public int size() {
return readMethods.size();
}
/**
* Get the keys for this BeanMap.
* <p>
* Write-only properties are <b>not</b> included in the returned set of
* property names, although it is possible to set their value and to get
* their type.
*
* @return BeanMap keys. The Set returned by this method is not
* modifiable.
*/
@Override
public Set<String> keySet() {
return readMethods.keySet();
}
/**
* Gets a Set of MapEntry objects that are the mappings for this BeanMap.
* <p>
* Each MapEntry can be set but not removed.
*
* @return the unmodifiable set of mappings
*/
@Override
public Set<Entry<String, Object>> entrySet() {
return new AbstractSet<Entry<String, Object>>() {
@Override
public Iterator<Entry<String, Object>> iterator() {
return entryIterator();
}
@Override
public int size() {
return BeanMap.this.readMethods.size();
}
};
}
/**
* Returns the values for the BeanMap.
*
* @return values for the BeanMap. The returned collection is not
* modifiable.
*/
@Override
public Collection<Object> values() {
List<Object> answer = new ArrayList<Object>(readMethods.size());
for (Iterator<Object> iter = valueIterator(); iter.hasNext();) {
answer.add(iter.next());
}
return answer;
}
// Helper methods
//-------------------------------------------------------------------------
/**
* Returns the type of the property with the given name.
*
* @param name the name of the property
* @return the type of the property, or {@code null} if no such
* property exists
*/
public Class<?> getType(String name) {
return types.get(name);
}
/**
* Convenience method for getting an iterator over the keys.
* <p>
* Write-only properties will not be returned in the iterator.
*
* @return an iterator over the keys
*/
public Iterator<String> keyIterator() {
return readMethods.keySet().iterator();
}
/**
* Convenience method for getting an iterator over the values.
*
* @return an iterator over the values
*/
public Iterator<Object> valueIterator() {
final Iterator<String> iter = keyIterator();
return new Iterator<Object>() {
@Override
public boolean hasNext() {
return iter.hasNext();
}
@Override
public Object next() {
Object key = iter.next();
return get(key);
}
@Override
public void remove() {
throw new UnsupportedOperationException("remove() not supported for BeanMap");
}
};
}
/**
* Convenience method for getting an iterator over the entries.
*
* @return an iterator over the entries
*/
public Iterator<Entry<String, Object>> entryIterator() {
final Iterator<String> iter = keyIterator();
return new Iterator<Entry<String, Object>>() {
@Override
public boolean hasNext() {
return iter.hasNext();
}
@Override
public Entry<String, Object> next() {
String key = iter.next();
Object value = get(key);
return new MyMapEntry(BeanMap.this, key, value);
}
@Override
public void remove() {
throw new UnsupportedOperationException("remove() not supported for BeanMap");
}
};
}
// Properties
//-------------------------------------------------------------------------
/**
* Returns the bean currently being operated on. The return value may
* be null if this map is empty.
*
* @return the bean being operated on by this map
*/
public Object getBean() {
return bean;
}
/**
* Sets the bean to be operated on by this map. The given value may
* be null, in which case this map will be empty.
*
* @param newBean the new bean to operate on
*/
public void setBean(Object newBean) {
bean = newBean;
reinitialise();
}
/**
* Returns the accessor for the property with the given name.
*
* @param name the name of the property
* @return the accessor method for the property, or null
*/
public Method getReadMethod(String name) {
return readMethods.get(name);
}
/**
* Returns the mutator for the property with the given name.
*
* @param name the name of the property
* @return the mutator method for the property, or null
*/
public Method getWriteMethod(String name) {
return writeMethods.get(name);
}
// Implementation methods
//-------------------------------------------------------------------------
/**
* Reinitializes this bean. Called during {@link #setBean(Object)}.
* Does introspection to find properties.
*/
protected void reinitialise() {
readMethods.clear();
writeMethods.clear();
types.clear();
initialise();
}
private void initialise() {
if (getBean() == null) {
return;
}
Class<?> beanClass = getBean().getClass();
try {
//BeanInfo beanInfo = Introspector.getBeanInfo( bean, null );
BeanInfo beanInfo = Introspector.getBeanInfo(beanClass);
PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors();
if (propertyDescriptors != null) {
for (int i = 0; i < propertyDescriptors.length; i++) {
PropertyDescriptor propertyDescriptor = propertyDescriptors[i];
if (propertyDescriptor != null) {
String name = propertyDescriptor.getName();
Method readMethod = propertyDescriptor.getReadMethod();
Method writeMethod = propertyDescriptor.getWriteMethod();
Class<?> aType = propertyDescriptor.getPropertyType();
if (readMethod != null) {
readMethods.put(name, readMethod);
}
if (writeMethods != null) {
writeMethods.put(name, writeMethod);
}
types.put(name, aType);
}
}
}
} catch (IntrospectionException e) {
}
}
/**
* Called during a successful {@link #put(Object,Object)} operation.
* Default implementation does nothing. Override to be notified of
* property changes in the bean caused by this map.
*
* @param key the name of the property that changed
* @param oldValue the old value for that property
* @param newValue the new value for that property
*/
protected void firePropertyChange(String key, Object oldValue, Object newValue) {
}
// Implementation classes
//-------------------------------------------------------------------------
/**
* Map entry used by {@link BeanMap}.
*/
protected static class MyMapEntry implements Map.Entry<String, Object> {
private final BeanMap owner;
private String key;
private Object value;
/**
* Constructs a new <code>MyMapEntry</code>.
*
* @param owner the BeanMap this entry belongs to
* @param key the key for this entry
* @param value the value for this entry
*/
protected MyMapEntry(BeanMap owner, String key, Object value) {
this.key = key;
this.value = value;
this.owner = owner;
}
/**
* Sets the value.
*
* @param value the new value for the entry
* @return the old value for the entry
*/
@Override
public Object setValue(Object value) {
String key = getKey();
Object oldValue = owner.get(key);
owner.put(key, value);
Object newValue = owner.get(key);
this.value = newValue;
return oldValue;
}
@Override
public String getKey() {
return key;
}
@Override
public Object getValue() {
return value;
}
}
/**
* Creates an array of parameters to pass to the given mutator method.
* If the given object is not the right type to pass to the method
* directly, it will be converted using {@link #convertType(Class,Object)}.
*
* @param method the mutator method
* @param value the value to pass to the mutator method
* @return an array containing one object that is either the given value
* or a transformed value
* @throws IllegalAccessException if {@link #convertType(Class,Object)}
* raises it
* @throws IllegalArgumentException if any other exception is raised
* by {@link #convertType(Class,Object)}
*/
protected Object[] createWriteMethodArguments(Method method, Object value) throws IllegalAccessException {
try {
if (value != null) {
Class<?>[] types = method.getParameterTypes();
if (types != null && types.length > 0) {
Class<?> paramType = types[0];
if (paramType.isPrimitive()) {
paramType = Primitives.wrap(paramType);
}
if (!paramType.isAssignableFrom(value.getClass())) {
value = convertType(paramType, value);
}
}
}
return new Object[]{value};
} catch (InvocationTargetException e) {
throw new IllegalArgumentException(e.getMessage());
} catch (InstantiationException e) {
throw new IllegalArgumentException(e.getMessage());
}
}
/**
* Converts the given value to the given type. First, reflection is
* is used to find a public constructor declared by the given class
* that takes one argument, which must be the precise type of the
* given value. If such a constructor is found, a new object is
* created by passing the given value to that constructor, and the
* newly constructed object is returned.<P>
* <p>
* If no such constructor exists, and the given type is a primitive
* type, then the given value is converted to a string using its
* {@link Object#toString() toString()} method, and that string is
* parsed into the correct primitive type using, for instance,
* {@link Integer#valueOf(String)} to convert the string into an
* {@code int}.<P>
* <p>
* If no special constructor exists and the given type is not a
* primitive type, this method returns the original value.
*
* @param newType the type to convert the value to
* @param value the value to convert
* @return the converted value
* @throws NumberFormatException if newType is a primitive type, and
* the string representation of the given value cannot be converted
* to that type
* @throws InstantiationException if the constructor found with
* reflection raises it
* @throws InvocationTargetException if the constructor found with
* reflection raises it
* @throws IllegalAccessException never
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
protected Object convertType(Class<?> newType, Object value) throws InstantiationException, IllegalAccessException, InvocationTargetException {
// try call constructor
Class<?>[] types = {value.getClass()};
try {
Constructor<?> constructor = newType.getConstructor(types);
Object[] arguments = {value};
return constructor.newInstance(arguments);
} catch (NoSuchMethodException e) {
// try using the transformers
Function function = getTypeFunction(newType);
if (function != null) {
return function.apply(value);
}
return value;
}
}
/**
* Returns a transformer for the given primitive type.
*
* @param aType the primitive type whose transformer to return
* @return a transformer that will convert strings into that type,
* or null if the given type is not a primitive type
*/
protected Function<?,?> getTypeFunction(Class<?> aType) {
return defaultFunctions.get(aType);
}
}