beanmap.java

这是一个有关common beanutils 的源码

                ("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 readableKeys = map.readMethods.keySet().iterator();
        while (readableKeys.hasNext()) {
            Object 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 <code>clear()</code> differs from the Map contract in that
     * the mappings are not actually removed from the map (the mappings for a
     * BeanMap are fixed).
     */
    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</code>; 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</code>;
     *   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(Object name) {
        Method method = getReadMethod(name);
        return method != null;
    }

    /**
     * Returns true if the bean defines a property whose current value is
     * the given object.
     *
     * @param value  the value to check
     * @return false  true if the bean has at least one property whose 
     *   current value is that object, false otherwise
     */
    public boolean containsValue(Object value) {
        // use default implementation
        return super.containsValue(value);
    }

    /**
     * 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</code>.
     * If the bean defines a property with the given name, the value of
     * that property is returned.  Otherwise, <code>null</code> 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(Object name) {
        if ( bean != null ) {
            Method method = getReadMethod( name );
            if ( method != null ) {
                try {
                    return method.invoke( bean, NULL_ARGUMENTS );
                }
                catch (  IllegalAccessException e ) {
                    logWarn( e );
                }
                catch ( IllegalArgumentException e ) {
                    logWarn(  e );
                }
                catch ( InvocationTargetException e ) {
                    logWarn(  e );
                }
                catch ( NullPointerException e ) {
                    logWarn(  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
     * @throws IllegalArgumentException  if the given name is null;
     *   if the given name is not a {@link String}; if the bean doesn't
     *   define a property with that name; or if the bean property with
     *   that name is read-only
     * @throws ClassCastException if an error occurs creating the method args
     */
    public Object put(Object name, Object value) throws IllegalArgumentException, ClassCastException {
        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 ) {
                logInfo( e );
                throw new IllegalArgumentException( e.getMessage() );
            }
            catch ( IllegalAccessException e ) {
                logInfo( 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
     */
    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.
     */
    public Set keySet() {
        return UnmodifiableSet.decorate(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
     */
    public Set entrySet() {
        return UnmodifiableSet.decorate(new AbstractSet() {
            public Iterator iterator() {
                return entryIterator();
            }
            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.
     */
    public Collection values() {
        ArrayList answer = new ArrayList( readMethods.size() );
        for ( Iterator iter = valueIterator(); iter.hasNext(); ) {
            answer.add( iter.next() );
        }
        return UnmodifiableList.decorate(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</code> if no such
     *  property exists
     */
    public Class getType(String name) {
        return (Class) 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 keyIterator() {
        return readMethods.keySet().iterator();
    }

    /**
     * Convenience method for getting an iterator over the values.
     *
     * @return an iterator over the values
     */
    public Iterator valueIterator() {
        final Iterator iter = keyIterator();
        return new Iterator() {            
            public boolean hasNext() {
                return iter.hasNext();
            }
            public Object next() {
                Object key = iter.next();
                return get(key);
            }
            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 entryIterator() {
        final Iterator iter = keyIterator();
        return new Iterator() {            
            public boolean hasNext() {
                return iter.hasNext();
            }            
            public Object next() {
                Object key = iter.next();
                Object value = get(key);
                return new Entry( BeanMap.this, key, value );
            }            
            public void remove() {
                throw new UnsupportedOperationException( "remove() not supported for BeanMap" );
            }
        };
    }


    // Properties
    //-------------------------------------------------------------------------

    /**
     * Returns the bean currently being operated on.  The return value may