Jetty example source code file (JSONObjectConvertor.java)

This example Jetty source code file (JSONObjectConvertor.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

class, illegalargumentexception, jsonobjectconvertor, jsonobjectconvertor, method, method, object, object, output, reflection, set, string, string, throwable, unsupportedoperationexception, util

The Jetty JSONObjectConvertor.java source code

package org.mortbay.util.ajax;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

import org.mortbay.util.ajax.JSON.Output;

/* ------------------------------------------------------------ */
/**
 * Convert an Object to JSON using reflection on getters methods.
 * 
 * @author gregw
 *
 */
public class JSONObjectConvertor implements JSON.Convertor
{
    private boolean _fromJSON;
    private Set _excluded=null;

    public JSONObjectConvertor()
    {
        _fromJSON=false;
    }
    
    public JSONObjectConvertor(boolean fromJSON)
    {
        _fromJSON=fromJSON;
    }
    
    /* ------------------------------------------------------------ */
    /**
     * @param fromJSON
     * @param excluded An array of field names to exclude from the conversion
     */
    public JSONObjectConvertor(boolean fromJSON,String[] excluded)
    {
        _fromJSON=fromJSON;
        if (excluded!=null)
            _excluded=new HashSet(Arrays.asList(excluded));
    }

    public Object fromJSON(Map map)
    {
        if (_fromJSON)
            throw new UnsupportedOperationException();
        return map;
    }

    public void toJSON(Object obj, Output out)
    {
        try
        {
            Class c=obj.getClass();

            if (_fromJSON)
                out.addClass(obj.getClass());

            Method[] methods = obj.getClass().getMethods();

            for (int i=0;i<methods.length;i++)
            {
                Method m=methods[i];
                if (!Modifier.isStatic(m.getModifiers()) &&  
                        m.getParameterTypes().length==0 && 
                        m.getReturnType()!=null &&
                        m.getDeclaringClass()!=Object.class)
                {
                    String name=m.getName();
                    if (name.startsWith("is"))
                        name=name.substring(2,3).toLowerCase()+name.substring(3);
                    else if (name.startsWith("get"))
                        name=name.substring(3,4).toLowerCase()+name.substring(4);
                    else
                        continue;

                    if (includeField(name,obj,m))
                        out.add(name, m.invoke(obj,(Object[])null));
                }
            }
        } 
        catch (Throwable e)
        {
            // e.printStackTrace();
            throw new IllegalArgumentException(e);
        }
    }
    
    protected boolean includeField(String name, Object o, Method m)
    {
        return _excluded==null || !_excluded.contains(name);
    }

}