com.comtop.cap.bm.metadata.common.dwr.CapMapConverter.java Source code

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/*
 * Copyright 2005 Joe Walker
 *
 * 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.comtop.cap.bm.metadata.common.dwr;

import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.StringTokenizer;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import comtop.org.directwebremoting.ConversionException;
import comtop.org.directwebremoting.extend.ConvertUtil;
import comtop.org.directwebremoting.extend.Converter;
import comtop.org.directwebremoting.extend.ConverterManager;
import comtop.org.directwebremoting.extend.InboundContext;
import comtop.org.directwebremoting.extend.InboundVariable;
import comtop.org.directwebremoting.extend.ObjectOutboundVariable;
import comtop.org.directwebremoting.extend.OutboundContext;
import comtop.org.directwebremoting.extend.OutboundVariable;
import comtop.org.directwebremoting.extend.Property;
import comtop.org.directwebremoting.extend.ProtocolConstants;
import comtop.org.directwebremoting.util.JavascriptUtil;
import comtop.org.directwebremoting.util.LocalUtil;

/**
 * An implementation of Converter for Maps.
 * @author Joe Walker [joe at getahead dot ltd dot uk]
 */
public class CapMapConverter implements Converter {
    /* (non-Javadoc)
     * @see org.directwebremoting.Converter#setConverterManager(org.directwebremoting.ConverterManager)
     */
    @Override
    public void setConverterManager(ConverterManager converterManager) {
        this.converterManager = converterManager;
    }

    /* (non-Javadoc)
     * @see org.directwebremoting.Converter#convertInbound(java.lang.Class, org.directwebremoting.InboundVariable, org.directwebremoting.InboundContext)
     */
    @Override
    @SuppressWarnings({ "unchecked", "rawtypes" })
    public Object convertInbound(Class<?> paramType, InboundVariable data) throws ConversionException {
        if (data.isNull()) {
            return null;
        }

        String value = data.getValue();

        // If the text is null then the whole bean is null
        if (value.trim().equals(ProtocolConstants.INBOUND_NULL)) {
            return null;
        }

        if (!value.startsWith(ProtocolConstants.INBOUND_MAP_START)
                || !value.endsWith(ProtocolConstants.INBOUND_MAP_END)) {
            log.warn("Expected object while converting data for " + paramType.getName() + " in "
                    + data.getContext().getCurrentProperty() + ". Passed: " + value);
            throw new ConversionException(paramType, "Data conversion error. See logs for more details.");
        }

        value = value.substring(1, value.length() - 1);

        try {
            // Maybe we ought to check that the paramType isn't expecting a more
            // distinct type of Map and attempt to create that?
            Map<Object, Object> map;

            // If paramType is concrete then just use whatever we've got.
            if (!paramType.isInterface() && !Modifier.isAbstract(paramType.getModifiers())) {
                // If there is a problem creating the type then we have no way
                // of completing this - they asked for a specific type and we
                // can't create that type. I don't know of a way of finding
                // subclasses that might be instaniable so we accept failure.
                map = (Map<Object, Object>) paramType.newInstance();
            } else {
                map = new HashMap<Object, Object>();
            }

            // Get the extra type info
            Property parent = data.getContext().getCurrentProperty();

            Property keyProp = parent.createChild(0);
            keyProp = converterManager.checkOverride(keyProp);

            Property valProp = parent.createChild(1);
            valProp = converterManager.checkOverride(valProp);

            // We should put the new object into the working map in case it
            // is referenced later nested down in the conversion process.
            data.getContext().addConverted(data, paramType, map);
            InboundContext incx = data.getContext();

            // Loop through the property declarations
            StringTokenizer st = new StringTokenizer(value, ",");
            int size = st.countTokens();
            for (int i = 0; i < size; i++) {
                String token = st.nextToken();
                if (token.trim().length() == 0) {
                    continue;
                }

                int colonpos = token.indexOf(ProtocolConstants.INBOUND_MAP_ENTRY);
                if (colonpos == -1) {
                    throw new ConversionException(paramType, "Missing " + ProtocolConstants.INBOUND_MAP_ENTRY
                            + " in object description: {1}" + token);
                }

                String valStr = token.substring(colonpos + 1).trim();
                String[] splitIv = ConvertUtil.splitInbound(valStr);
                String splitIvValue = splitIv[ConvertUtil.INBOUND_INDEX_VALUE];
                String splitIvType = splitIv[ConvertUtil.INBOUND_INDEX_TYPE];
                InboundVariable valIv = new InboundVariable(incx, null, splitIvType, splitIvValue);
                valIv.dereference();

                Class valTyClass = String.class;

                if ("boolean".equals(valIv.getType())) {
                    valTyClass = Boolean.class;
                } else if ("array".equals(valIv.getType())) {
                    valTyClass = ArrayList.class;
                } else if ("number".equals(valIv.getType())) {
                    String strValue = valIv.getValue();
                    if (strValue.indexOf(".") != -1) {
                        valTyClass = Double.class;
                    } else {
                        valTyClass = Integer.class;
                    }
                } else if ("date".equals(valIv.getType())) {
                    valTyClass = Date.class;
                }

                Object val = converterManager.convertInbound(valTyClass, valIv, valProp);
                String keyStr = token.substring(0, colonpos).trim();
                map.put(keyStr, val);
            }

            return map;
        } catch (ConversionException ex) {
            throw ex;
        } catch (Exception ex) {
            throw new ConversionException(paramType, ex);
        }
    }

    /* (non-Javadoc)
     * @see org.directwebremoting.Converter#convertOutbound(java.lang.Object, org.directwebremoting.OutboundContext)
     */
    @Override
    @SuppressWarnings("unchecked")
    public OutboundVariable convertOutbound(Object data, OutboundContext outctx) throws ConversionException {
        // First we just collect our converted children
        //noinspection unchecked
        Map<String, OutboundVariable> ovs = LocalUtil.classNewInstance("OrderedConvertOutbound",
                "java.util.LinkedHashMap", Map.class);
        if (ovs == null) {
            ovs = new HashMap<String, OutboundVariable>();
        }

        ObjectOutboundVariable ov = new ObjectOutboundVariable(outctx);
        outctx.put(data, ov);

        // Loop through the map outputting any init code and collecting
        // converted outbound variables into the ovs map
        Map<Object, Object> map = (Map<Object, Object>) data;
        for (Entry<Object, Object> entry : map.entrySet()) {
            Object key = entry.getKey();
            Object value = entry.getValue();

            // If the key is null, retrieve the configured null key value from the configuration of this converter.
            if (null == key && null != nullKey) {
                log.debug("MapConverter: A null key was encountered DWR is using the configured nullKey string: "
                        + nullKey);
                key = nullKey;
            }

            // It would be nice to check for Enums here
            if (!(key instanceof String) && !sentNonStringWarning && key != null) {
                log.warn("--Javascript does not support non string keys. Converting '" + key.getClass().getName()
                        + "' using toString()");
                sentNonStringWarning = true;
            }

            String outkey = JavascriptUtil.escapeJavaScript(key != null ? key.toString() : null);

            /*
            OutboundVariable ovkey = converterManager.convertOutbound(key, outctx);
            buffer.append(ovkey.getInitCode());
            outkey = ovkey.getAssignCode();
             */

            OutboundVariable nested = converterManager.convertOutbound(value, outctx);

            ovs.put(outkey, nested);
        }

        ov.setChildren(ovs);

        return ov;
    }

    /**
     * @return the nullKey
     */
    public String getNullKey() {
        return nullKey;
    }

    /**
     * @param nullKey the nullKey to set
     */
    public void setNullKey(String nullKey) {
        this.nullKey = nullKey;
    }

    /**
     * We don't want to give the non-string warning too many times.
     */
    private static boolean sentNonStringWarning = false;

    /**
     * To forward marshalling requests
     */
    private ConverterManager converterManager = null;

    /**
     * Used by DWR if a null key is encountered.  Configure in the init section when the map converter is declared.
     * <converter id="map" class="org.directwebremoting.convert.MapConverter">
     *     <param name="nullKey" value="null" />
     * </converter>
     */
    private String nullKey = null;

    /**
     * The log stream
     */
    private static final Log log = LogFactory.getLog(CapMapConverter.class);
}