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Jetty example source code file (JSONDataFilter.java)

This example Jetty source code file (JSONDataFilter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Jetty tags/keywords

boolean, cannot, channel, channel, collection, datafilter, list, map, map, number, object, object, reflection, string, string, util

The Jetty JSONDataFilter.java source code

// ========================================================================
// Copyright 2007 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// 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.mortbay.cometd.filter;

import java.lang.reflect.Array;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.mortbay.cometd.ClientImpl;
import org.mortbay.log.Log;
import org.mortbay.util.ajax.JSON;

import dojox.cometd.Channel;
import dojox.cometd.Client;
import dojox.cometd.DataFilter;

/** JSON DataFilter
 * This {@link DataFilter} walks an Object as if it was a call to {@link JSON#toString(Object)} and 
 * calls the protected methods 
 * {@link #filterString(String)},
 * {@link #filterNumber(Number)},
 * {@link #filterBoolean(Boolean)},
 * {@link #filterArray(Object, ClientImpl)} or
 * {@link #filterMap(Map, ClientImpl)} appropriate.
 * Derived filters may override one or more of these methods to provide filtering of specific types.
 * 
 * @author gregw
 *
 */
public class JSONDataFilter implements DataFilter
{
    public void init(Object init)
    {}
    
    public Object filter(Client from, Channel to, Object data) throws IllegalStateException
    {
        if (data==null)
            return null;
        
        if (data instanceof Map)
            return filterMap(from,to,(Map)data);
        if (data instanceof List)
            return filterArray(from,to,((List) data).toArray ());
        if (data instanceof Collection)
        	return filterArray(from,to,((Collection)data).toArray());
        if (data.getClass().isArray() )
            return filterArray(from,to,data);
        if (data instanceof Number)
            return filterNumber((Number)data);
        if (data instanceof Boolean)
            return filterBoolean((Boolean)data);
        if (data instanceof String)
            return filterString((String)data);
        if (data instanceof JSON.Literal)
            return filterJSON(from,to,(JSON.Literal)data);
        if (data instanceof JSON.Generator)
            return filterJSON(from,to,(JSON.Generator)data);
        return filterObject(from,to,data);
    }

    protected Object filterString(String string)
    {
        return string;
    }

    protected Object filterBoolean(Boolean bool)
    {
        return bool;
    }

    protected Object filterNumber(Number number)
    {
        return number;
    }

    protected Object filterArray(Client from, Channel to, Object array)
    {
       if (array==null)
            return null;
        
        int length = Array.getLength(array);
        
        for (int i=0;i<length;i++)
            Array.set(array,i,filter(from, to, Array.get(array,i)));
        
        return array;
    }

    protected Object filterMap(Client from, Channel to, Map object)
    {
        if (object==null)
            return null;
        
        Iterator iter = object.entrySet().iterator();
        while(iter.hasNext())
        {
            Map.Entry entry = (Map.Entry)iter.next();
            entry.setValue(filter(from, to, entry.getValue()));
        }

        return object;
    }

    protected Object filterJSON(Client from, Channel to, JSON.Generator generator)
    {
        String json = JSON.toString(generator);
        Object data = JSON.parse (json);
        return filter(from,to,data);
    }

    protected Object filterJSON(Client from, Channel to, JSON.Literal json)
    {
        Object data = JSON.parse(json.toString());
        return filter(from,to,data);
    }
    
    protected Object filterObject(Client from, Channel to, Object obj)
    {
        Log.warn(this+": Cannot Filter "+obj.getClass());
        return obj;
    }

}

Other Jetty examples (source code examples)

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