org.apache.shindig.protocol.conversion.BeanAtomConverter.java Source code

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Here is the source code for org.apache.shindig.protocol.conversion.BeanAtomConverter.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.apache.shindig.protocol.conversion;

import org.apache.commons.betwixt.IntrospectionConfiguration;
import org.apache.commons.betwixt.io.BeanReader;
import org.apache.commons.betwixt.io.BeanWriter;
import org.apache.shindig.protocol.ContentTypes;

import org.xml.sax.SAXException;

import java.beans.IntrospectionException;
import java.io.IOException;
import java.io.StringReader;
import java.io.StringWriter;
import java.util.logging.Level;
import java.util.logging.Logger;

// TODO: This does not produce valid atom sytnax yet
/**
 * Converts a Bean into Atom-like syntax.
 */
public class BeanAtomConverter implements BeanConverter {
    private static final Logger LOG = Logger.getLogger(BeanAtomConverter.class.getName());

    public String getContentType() {
        return ContentTypes.OUTPUT_ATOM_CONTENT_TYPE;
    }

    public String convertToString(Object pojo) {
        return convertToXml(pojo);
    }

    public String convertToXml(Object obj) {
        String xmlHead = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>";
        StringWriter outputWriter = new StringWriter();
        BeanWriter writer = new BeanWriter(outputWriter);
        IntrospectionConfiguration configuration = writer.getXMLIntrospector().getConfiguration();
        configuration.setAttributesForPrimitives(false);
        configuration.setWrapCollectionsInElement(true);

        writer.getBindingConfiguration().setMapIDs(false);
        // Print no line endings
        writer.setEndOfLine("");
        writer.setWriteEmptyElements(false);

        // Still left to do:
        //
        // Fix map output with custom outputter:
        // for a map with {key : value, key2 : value2} we need:
        // <key>value</key> <key2>value2</key2>

        // Supress empty lists

        // Within a list the items need to be renamed - this probably means with need a .betwixt file

        String toReturn = xmlHead;
        try {
            writer.write("response", obj);
            toReturn = toReturn + outputWriter.toString();
            if (LOG.isLoggable(Level.FINEST))
                LOG.finest("XML is: " + toReturn + "\n **** \n\n");

        } catch (SAXException e) {
            LOG.log(Level.SEVERE, e.getMessage(), e);
        } catch (IOException e) {
            LOG.log(Level.SEVERE, e.getMessage(), e);
        } catch (IntrospectionException e) {
            LOG.log(Level.SEVERE, e.getMessage(), e);
        } finally {
            try {
                writer.close();
            } catch (IOException e) {
                if (LOG.isLoggable(Level.FINEST))
                    LOG.log(Level.FINEST, e.getMessage(), e);
            }
        }

        return toReturn;
    }

    public static final String ERROR_MESSAGE_FMT = "Could not convert %s to %s";

    @SuppressWarnings("unchecked")
    public <T> T convertToObject(String xml, Class<T> className) {
        xml = xml.substring(xml.indexOf("?>") + 2);
        BeanReader reader = new BeanReader();
        try {
            reader.registerBeanClass("activity", className);
            StringReader rd = new StringReader(xml);
            return (T) reader.parse(rd);
        } catch (IntrospectionException e) {
            throw new RuntimeException(String.format(ERROR_MESSAGE_FMT, xml, className), e);
        } catch (IOException e) {
            throw new RuntimeException(String.format(ERROR_MESSAGE_FMT, xml, className), e);
        } catch (SAXException e) {
            throw new RuntimeException(String.format(ERROR_MESSAGE_FMT, xml, className), e);
        }
    }

    public void append(Appendable buf, Object pojo) throws IOException {
        buf.append(convertToString(pojo));
    }
}