osgi/bundles/org.eclipse.ecf.osgi.services.remoteserviceadmin/src/org/eclipse/ecf/osgi/services/remoteserviceadmin/EndpointDescriptionWriter.java

/*******************************************************************************
 * Copyright (c) 2010-2011 Composent, Inc. and others. All rights reserved. This
 * program and the accompanying materials are made available under the terms of
 * the Eclipse Public License v1.0 which accompanies this distribution, and is
 * available at http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   Composent, Inc. - initial API and implementation
 ******************************************************************************/
package org.eclipse.ecf.osgi.services.remoteserviceadmin;

import java.io.IOException;
import java.io.Writer;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

/**
 * Endpoint description writer class for writing {@link EndpointDescription}s to
 * the OSGi 4.2 Remote Service Admin Endpoint Description Extender Format
 * (section 122.8 of OSGi 4.2 enterprise specification). This class may be used
 * or extended to write {@link EndpointDescription} instances to the format
 * specified by OSGi 4.2 section 122.8.
 * 
 */
public class EndpointDescriptionWriter {

	protected String indent = "  "; //$NON-NLS-1$

	protected List<String> xmlNames;

	public EndpointDescriptionWriter() {
		this(null);
	}

	public EndpointDescriptionWriter(List<String> xmlNames) {
		this.xmlNames = xmlNames;
	}

	protected abstract class ComplexProperty {
		private String name;
		private Object value;

		public ComplexProperty(String name, Object value) {
			this.name = name;
			this.value = value;
		}

		public abstract void writeProperty(int indentLevel, Writer writer)
				throws IOException;

		protected String getName() {
			return name;
		}

		protected Object getValue() {
			return value;
		}
	}

	protected class XmlProperty extends ComplexProperty {
		public XmlProperty(String name, String xml) {
			super(name, xml);
		}

		void writeXml(int indentLevel, Writer writer) throws IOException {
			indent(indentLevel, writer);
			writer.append("<xml>"); //$NON-NLS-1$
			newLine(writer);
			indent(indentLevel + 1, writer);
			writer.append((String) getValue());
			newLine(writer);
			indent(indentLevel, writer);
			writer.append("</xml>"); //$NON-NLS-1$
			newLine(writer);
		}

		public void writeProperty(int indentLevel, Writer writer)
				throws IOException {
			indent(indentLevel, writer);
			writer.append("<property name=\"").append(getName()).append("\">"); //$NON-NLS-1$ //$NON-NLS-2$
			newLine(writer);
			writeXml(indentLevel + 1, writer);
			writer.append("</property>"); //$NON-NLS-1$
			newLine(writer);
		}
	}

	protected abstract class MultiValueProperty extends ComplexProperty {
		public MultiValueProperty(String name, Object value) {
			super(name, value);
		}

		abstract String getValueType();

		abstract void writePropertyValues(int indentLevel, Writer writer)
				throws IOException;

		public void writeProperty(int indentLevel, Writer writer)
				throws IOException {
			indent(indentLevel, writer);
			writer.append("<property name=\"").append(getName()) //$NON-NLS-1$
					.append("\" value-type=\"").append(getValueType()) //$NON-NLS-1$
					.append("\">"); //$NON-NLS-1$
			newLine(writer);
			writePropertyValues(indentLevel + 1, writer);
			indent(indentLevel, writer);
			writer.append("</property>"); //$NON-NLS-1$
			newLine(writer);
		}

		void writePropertyValue(int indentLevel, Object value, Writer writer)
				throws IOException {
			indent(indentLevel, writer);
			writer.append("<value>").append(value.toString()) //$NON-NLS-1$
					.append("</value>"); //$NON-NLS-1$
			newLine(writer);
		}

	}

	protected class SetProperty extends MultiValueProperty {
		public SetProperty(String key, Set value) {
			super(key, value);
		}

		public String getValueType() {
			return EndpointDescriptionWriter.this
					.getValueType(((Set) getValue()).iterator().next());
		}

		void writePropertyValues(int indentLevel, Writer writer)
				throws IOException {
			Set s = (Set) getValue();
			indent(indentLevel, writer);
			writer.append("<set>"); //$NON-NLS-1$
			newLine(writer);
			for (Iterator i = s.iterator(); i.hasNext();)
				writePropertyValue(indentLevel + 1, i.next(), writer);
			indent(indentLevel, writer);
			writer.append("</set>"); //$NON-NLS-1$
		}

	}

	protected class ListProperty extends MultiValueProperty {
		public ListProperty(String key, List value) {
			super(key, value);
		}

		public String getValueType() {
			return EndpointDescriptionWriter.this
					.getValueType(((List) getValue()).iterator().next());
		}

		void writePropertyValues(int indentLevel, Writer writer)
				throws IOException {
			List l = (List) getValue();
			indent(indentLevel, writer);
			writer.append("<list>"); //$NON-NLS-1$
			newLine(writer);
			for (Iterator i = l.iterator(); i.hasNext();)
				writePropertyValue(indentLevel + 1, i.next(), writer);
			indent(indentLevel, writer);
			writer.append("</list>"); //$NON-NLS-1$
			newLine(writer);
		}
	}

	protected class ArrayProperty extends MultiValueProperty {
		public ArrayProperty(String key, Object[] value) {
			super(key, value);
		}

		public String getValueType() {
			return EndpointDescriptionWriter.this
					.getValueType(((Object[]) getValue())[0]);
		}

		void writePropertyValues(int indentLevel, Writer writer)
				throws IOException {
			Object[] a = (Object[]) getValue();
			indent(indentLevel, writer);
			writer.append("<array>"); //$NON-NLS-1$
			newLine(writer);
			for (int i = 0; i < a.length; i++)
				writePropertyValue(indentLevel + 1, a[i], writer);
			indent(indentLevel, writer);
			writer.append("</array>"); //$NON-NLS-1$
			newLine(writer);
		}
	}

	public void writeEndpointDescriptions(
			Writer writer,
			org.osgi.service.remoteserviceadmin.EndpointDescription[] endpointDescriptions)
			throws IOException {

		indent(0, writer);
		writer.append("<endpoint-descriptions xmlns=\"http://www.osgi.org/xmlns/rsa/v1.0.0\">"); //$NON-NLS-1$
		newLine(writer);
		for (int i = 0; i < endpointDescriptions.length; i++)
			writeEndpointDescription(1, writer, endpointDescriptions[i]);
		indent(0, writer);
		writer.append("</endpoint-descriptions>"); //$NON-NLS-1$
		newLine(writer);
	}

	protected void writeEndpointDescription(
			int indentLevel,
			Writer writer,
			org.osgi.service.remoteserviceadmin.EndpointDescription endpointDescription)
			throws IOException {
		indent(indentLevel, writer);
		writer.append("<endpoint-description>"); //$NON-NLS-1$
		newLine(writer);
		writeProperties(indentLevel, writer, endpointDescription);
		indent(indentLevel, writer);
		writer.append("</endpoint-description>"); //$NON-NLS-1$
		newLine(writer);
	}

	protected void writeProperties(
			int indentLevel,
			Writer writer,
			org.osgi.service.remoteserviceadmin.EndpointDescription endpointDescription)
			throws IOException {
		Map<String, Object> properties = endpointDescription.getProperties();
		for (String name : properties.keySet())
			writeProperty(indentLevel + 1, writer, name, properties.get(name));
	}

	protected void writeProperty(int indentLevel, Writer writer, String name,
			Object value) throws IOException {
		if (value != null) {
			ComplexProperty complexProperty = getComplexProperty(name, value);
			if (complexProperty != null) {
				complexProperty.writeProperty(indentLevel, writer);
				return;
			}
			String valueType = getValueType(value);
			if (valueType != null) {
				writeValueProperty(indentLevel, name, valueType, value, writer);
				return;
			} else
				writeUnknownProperty(indentLevel, writer, name, value);
		}
	}

	protected void writeUnknownProperty(int indentLevel, Writer writer,
			String name, Object value) {
		// By default, do nothing
	}

	protected ComplexProperty getComplexProperty(String name, Object value) {
		XmlProperty xmlProperty = getXmlProperty(name, value);
		return (xmlProperty == null) ? getMultiValueProperty(name, value)
				: xmlProperty;
	}

	protected XmlProperty getXmlProperty(String name, Object value) {
		if (xmlNames != null && xmlNames.contains(name))
			return new XmlProperty(name, (String) value);
		return null;
	}

	protected void writeValueProperty(int indentLevel, String name,
			String valueType, Object value, Writer writer) throws IOException {
		indent(indentLevel, writer);
		writer.append("<property name=\"").append(name) //$NON-NLS-1$
				.append("\" value-type=\"").append(valueType) //$NON-NLS-1$
				.append("\" value=\"").append(value.toString()).append("\"/>"); //$NON-NLS-1$ //$NON-NLS-2$
		newLine(writer);
	}

	protected MultiValueProperty getMultiValueProperty(String key, Object value) {
		if (value instanceof Set) {
			Set s = (Set) value;
			Object first = s.iterator().next();
			if (first == null)
				return null;
			return new SetProperty(key, s);
		} else if (value instanceof List) {
			List l = (List) value;
			Object first = l.get(0);
			if (first == null)
				return null;
			return new ListProperty(key, l);
		} else if (value.getClass().isArray()) {
			Object[] a = (Object[]) value;
			if (a.length == 0 || a[0] == null)
				return null;
			return new ArrayProperty(key, a);
		}
		return null;
	}

	protected String getValueType(Object value) {
		// first determine if is array
		if (value instanceof String)
			return "String"; //$NON-NLS-1$
		else if (value instanceof Long)
			return "Long"; //$NON-NLS-1$
		else if (value instanceof Double)
			return "Double"; //$NON-NLS-1$
		else if (value instanceof Float)
			return "Float"; //$NON-NLS-1$
		else if (value instanceof Integer)
			return "Integer"; //$NON-NLS-1$
		else if (value instanceof Byte)
			return "Byte"; //$NON-NLS-1$
		else if (value instanceof Character)
			return "Character"; //$NON-NLS-1$
		else if (value instanceof Boolean)
			return "Boolean"; //$NON-NLS-1$
		else if (value instanceof Short)
			return "Short"; //$NON-NLS-1$
		return null;
	}

	protected Writer newLine(Writer writer) throws IOException {
		return writer.append("\n"); //$NON-NLS-1$
	}

	protected Writer indent(int indentLevel, Writer writer) throws IOException {
		for (int i = 0; i < indentLevel; i++)
			writer.append(indent);
		return writer;
	}

}