org.apache.ace.deployment/src/org/apache/ace/deployment/provider/repositorybased/BaseRepositoryHandler.java - ace - Git at Google

 /*
  * 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.ace.deployment.provider.repositorybased;

 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;

 import org.osgi.framework.Version;
 import org.xml.sax.Attributes;
 import org.xml.sax.SAXException;
 import org.xml.sax.helpers.DefaultHandler;

 /**
  * Provides a SAX-based push parser for obtaining all versions of the deployment packages of a certain target.
  */
 class BaseRepositoryHandler extends DefaultHandler {

     private final String m_targetID;

     /** Denotes the current tag in the XML structure. */
     private XmlTag m_currentTag;
     /** Denotes the current version of the found target. */
     private Version m_currentVersion;
     /** Denotes whether or not the requested target is found. */
     private boolean m_targetFound;
     /** Denotes the current deployment artifact. */
     private XmlDeploymentArtifact m_currentArtifact;
     /** Denotes the directive key of the current deployment artifact. */
     private String m_currentDirectiveKey;
     /** Denotes the size of an artifact. */
     private long m_artifactSize;
     /** Denotes the actual URL to the artifact. */
     private URL m_artifactURL;
     /** To collect characters() */
     private final StringBuilder m_buffer;

     /**
      * Creates a new {@link BaseRepositoryHandler} instance.
      *
      * @param targetID
      *            the target ID to search for, cannot be <code>null</code>.
      */
     public BaseRepositoryHandler(String targetID) {
         m_targetID = targetID;
         m_currentTag = XmlTag.unknown;
         m_buffer = new StringBuilder();
     }

     /**
      * Parses the given text as {@link Version}.
      *
      * @param text
      *            the text to parse as version, can not be <code>null</code>.
      * @return a {@link Version} if the given text represent a correct version, never <code>null</code>.
      */
     static final Version parseVersion(String text) {
         try {
             if (text != null) {
                 return Version.parseVersion(text);
             }
         }
         catch (Exception e) {
             // Ignore; simply return an empty version to denote this invalid version...
         }
         return Version.emptyVersion;
     }

     @Override
     public void startDocument() throws SAXException {
         m_currentTag = XmlTag.unknown;
         m_currentVersion = null;
         m_targetFound = false;
         m_currentArtifact = null;
         m_currentDirectiveKey = null;
         m_artifactURL = null;
         m_artifactSize = -1L;
     }

     @Override
     public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
         XmlTag tag = XmlTag.asXmlTag(qName);
         // If the given element is an expected child of the current tag, we
         // traverse deeper into the XML-hierarchy; otherwise, consider it an
         // "unknown"/uninteresting child and keep the current tag as-is...
         if (m_currentTag.isExpectedChild(tag)) {
             m_currentTag = tag;
         }

         m_currentDirectiveKey = null;
         // If we're parsing the directives of an artifact, take the name for
         // later use (the literal text in this tag will be used as value)...
         if (XmlTag.directives.equals(m_currentTag)) {
             m_currentDirectiveKey = qName;
         }
         if (XmlTag.size.equals(m_currentTag)) {
             m_artifactSize = -1L;
         }
         m_buffer.setLength(0);
     }

     @Override
     public void characters(char[] ch, int start, int length) throws SAXException {
         // just collect whatever comes along into our buffer (ACE-399)
         // see: http://stackoverflow.com/questions/4567636/java-sax-parser-split-calls-to-characters
         m_buffer.append(ch, start, length);
     }

     @Override
     public void endElement(String uri, String localName, String qName) throws SAXException {
         String text = m_buffer.toString();

         if (XmlTag.targetID.equals(m_currentTag)) {
             // verify whether we're in the DP for the requested target...
             m_targetFound = m_targetID.equals(text);
         }
         else if (XmlTag.version.equals(m_currentTag)) {
             // Don't assume we've got the desired version (yet)...
             m_currentVersion = null;

             if (m_targetFound) {
                 m_currentVersion = parseAsVersion(text);
             }
         }
         else if (XmlTag.url.equals(m_currentTag)) {
             try {
                 m_artifactURL = new URL(text);
             }
             catch (MalformedURLException e) {
                 throw new SAXException("Unexpected URL!", e);
             }
         }
         else if (XmlTag.size.equals(m_currentTag)) {
             try {
                 m_artifactSize = Long.valueOf(text);
             }
             catch (NumberFormatException exception) {
                 m_artifactSize = -1L;
             }
         }
         else if (XmlTag.directives.equals(m_currentTag)) {
             if (m_currentArtifact == null) {
                 m_currentArtifact = new XmlDeploymentArtifact(m_artifactURL, m_artifactSize);
             }
             String value = text.trim();
             if (m_currentDirectiveKey != null && !value.equals("")) {
                 m_currentArtifact.m_directives.put(m_currentDirectiveKey, value);
             }
         }

         XmlTag tag = XmlTag.asXmlTag(qName);
         // When we're ending the current tag, traverse up to its parent...
         if (!XmlTag.unknown.equals(tag) && (m_currentTag == tag)) {
             m_currentTag = tag.getParent();
         }

         // Invoke the callbacks for events we're interested in...
         if (XmlTag.version.equals(tag)) {
             if (m_currentVersion != null && !Version.emptyVersion.equals(m_currentVersion)) {
                 // Let the version be handled (if needed)...
                 handleVersion(m_currentVersion);
             }

             // Let the currentVersion field as-is! We want to reuse it for the artifacts...
         }
         else if (XmlTag.deploymentArtifact.equals(tag)) {
             if (m_currentArtifact != null) {
                 // push out the current deployment artifact...
                 handleArtifact(m_currentVersion, m_currentArtifact);
             }

             m_currentArtifact = null;
             m_artifactURL = null;
             m_artifactSize = -1L;
         }
         else if (XmlTag.directives.equals(tag)) {
             m_currentDirectiveKey = null;
         }
     }

     /**
      * Allows subclasses to handle the given version of a target's deployment package.
      * <p>
      * By default, this method does nothing.
      * </p>
      *
      * @param version
      *            the version found, never <code>null</code>.
      */
     protected void handleVersion(Version version) {
         // NO-op
     }

     /**
      * Allows subclasses to handle the given deployment artifact for the given version of the deployment package.
      * <p>
      * By default, this method does nothing.
      * </p>
      *
      * @param version
      *            the version of the deployment package;
      * @param artifact
      *            the deployment artifact itself.
      */
     protected void handleArtifact(Version version, XmlDeploymentArtifact artifact) {
         // NO-op
     }

     /**
      * Parses the given text as {@link Version}.
      *
      * @param text
      *            the text to parse as version, can not be <code>null</code>.
      * @return a {@link Version} if the given text represent a correct version, can be <code>null</code> in case of an
      *         incorrect/empty version..
      */
     protected final Version parseAsVersion(String text) {
         Version result = parseVersion(text);
         if (Version.emptyVersion.equals(result)) {
             return null;
         }
         return result;
     }

     /**
      * Helper class to store a pair of URL and directive, in which the directive may be empty.
      */
     public static class XmlDeploymentArtifact {
         private final URL m_url;
         private final long m_size;
         private final Map<String, String> m_directives;

         private XmlDeploymentArtifact(URL url, long size) {
             m_url = url;
             m_size = size;
             m_directives = new HashMap<>();
         }

         public long getSize() {
             return m_size;
         }

         public URL getUrl() {
             return m_url;
         }

         public Map<String, String> getDirective() {
             return m_directives;
         }
     }

     /**
      * Defines the structure of our XML (only the parts we're interested in).
      */
     public static enum XmlTag {
         targetID,
         version,
         attributes(targetID, version),
         url,
         size,
         directives,
         deploymentArtifact(url, size, directives),
         artifacts(deploymentArtifact),
         tags,
         deploymentversion(attributes, tags, artifacts),
         deploymentversions(deploymentversion),
         repository(deploymentversions),
         unknown(repository);

         private final XmlTag[] m_children;
         private XmlTag m_parent;

         private XmlTag(XmlTag... possibleChildren) {
             m_children = possibleChildren;
             // Update the children's parent...
             for (int i = 0; i < m_children.length; i++) {
                 m_children[i].m_parent = this;
             }
         }

         /**
          * Returns the parent tag of this tag.
          *
          * @return a parent tag, can be <code>null</code>.
          */
         public XmlTag getParent() {
             return m_parent;
         }

         /**
          * Returns whether the given XML tag is an expected child of this tag.
          *
          * @param xmlTag
          *            the XML tag to test, cannot be <code>null</code>.
          * @return <code>true</code> if the given tag is an expected child of this tag, <code>false</code> otherwise.
          */
         public boolean isExpectedChild(XmlTag xmlTag) {
             for (int i = 0; i < m_children.length; i++) {
                 if (xmlTag.equals(m_children[i])) {
                     return true;
                 }
             }
             return false;
         }

         /**
          * Provides a "safe" way of representing the given tag name as instance of this enum. If the given name does not
          * represent a defined tag, "unknown" will be returned.
          *
          * @param name
          *            the XML tag-name to represent as enum value, cannot be <code>null</code>.
          * @return a {@link XmlTag} representation of the given tag-name, never <code>null</code>.
          */
         public static XmlTag asXmlTag(String name) {
             XmlTag[] values = { artifacts, attributes, deploymentArtifact, deploymentversion, deploymentversions, directives, repository, size, tags, targetID, url, version };
             for (int i = 0; i < values.length; i++) {
                 if (values[i].name().equals(name)) {
                     return values[i];
                 }
             }
             return XmlTag.unknown;
         }
     }
 }
	/*
	* 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.ace.deployment.provider.repositorybased;

	import java.net.MalformedURLException;
	import java.net.URL;
	import java.util.HashMap;
	import java.util.Map;

	import org.osgi.framework.Version;
	import org.xml.sax.Attributes;
	import org.xml.sax.SAXException;
	import org.xml.sax.helpers.DefaultHandler;

	/**
	* Provides a SAX-based push parser for obtaining all versions of the deployment packages of a certain target.
	*/
	class BaseRepositoryHandler extends DefaultHandler {

	private final String m_targetID;

	/** Denotes the current tag in the XML structure. */
	private XmlTag m_currentTag;
	/** Denotes the current version of the found target. */
	private Version m_currentVersion;
	/** Denotes whether or not the requested target is found. */
	private boolean m_targetFound;
	/** Denotes the current deployment artifact. */
	private XmlDeploymentArtifact m_currentArtifact;
	/** Denotes the directive key of the current deployment artifact. */
	private String m_currentDirectiveKey;
	/** Denotes the size of an artifact. */
	private long m_artifactSize;
	/** Denotes the actual URL to the artifact. */
	private URL m_artifactURL;
	/** To collect characters() */
	private final StringBuilder m_buffer;

	/**
	* Creates a new {@link BaseRepositoryHandler} instance.
	*
	* @param targetID
	* the target ID to search for, cannot be <code>null</code>.
	*/
	public BaseRepositoryHandler(String targetID) {
	m_targetID = targetID;
	m_currentTag = XmlTag.unknown;
	m_buffer = new StringBuilder();
	}

	/**
	* Parses the given text as {@link Version}.
	*
	* @param text
	* the text to parse as version, can not be <code>null</code>.
	* @return a {@link Version} if the given text represent a correct version, never <code>null</code>.
	*/
	static final Version parseVersion(String text) {
	try {
	if (text != null) {
	return Version.parseVersion(text);
	}
	}
	catch (Exception e) {
	// Ignore; simply return an empty version to denote this invalid version...
	}
	return Version.emptyVersion;
	}

	@Override
	public void startDocument() throws SAXException {
	m_currentTag = XmlTag.unknown;
	m_currentVersion = null;
	m_targetFound = false;
	m_currentArtifact = null;
	m_currentDirectiveKey = null;
	m_artifactURL = null;
	m_artifactSize = -1L;
	}

	@Override
	public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
	XmlTag tag = XmlTag.asXmlTag(qName);
	// If the given element is an expected child of the current tag, we
	// traverse deeper into the XML-hierarchy; otherwise, consider it an
	// "unknown"/uninteresting child and keep the current tag as-is...
	if (m_currentTag.isExpectedChild(tag)) {
	m_currentTag = tag;
	}

	m_currentDirectiveKey = null;
	// If we're parsing the directives of an artifact, take the name for
	// later use (the literal text in this tag will be used as value)...
	if (XmlTag.directives.equals(m_currentTag)) {
	m_currentDirectiveKey = qName;
	}
	if (XmlTag.size.equals(m_currentTag)) {
	m_artifactSize = -1L;
	}
	m_buffer.setLength(0);
	}

	@Override
	public void characters(char[] ch, int start, int length) throws SAXException {
	// just collect whatever comes along into our buffer (ACE-399)
	// see: http://stackoverflow.com/questions/4567636/java-sax-parser-split-calls-to-characters
	m_buffer.append(ch, start, length);
	}

	@Override
	public void endElement(String uri, String localName, String qName) throws SAXException {
	String text = m_buffer.toString();

	if (XmlTag.targetID.equals(m_currentTag)) {
	// verify whether we're in the DP for the requested target...
	m_targetFound = m_targetID.equals(text);
	}
	else if (XmlTag.version.equals(m_currentTag)) {
	// Don't assume we've got the desired version (yet)...
	m_currentVersion = null;

	if (m_targetFound) {
	m_currentVersion = parseAsVersion(text);
	}
	}
	else if (XmlTag.url.equals(m_currentTag)) {
	try {
	m_artifactURL = new URL(text);
	}
	catch (MalformedURLException e) {
	throw new SAXException("Unexpected URL!", e);
	}
	}
	else if (XmlTag.size.equals(m_currentTag)) {
	try {
	m_artifactSize = Long.valueOf(text);
	}
	catch (NumberFormatException exception) {
	m_artifactSize = -1L;
	}
	}
	else if (XmlTag.directives.equals(m_currentTag)) {
	if (m_currentArtifact == null) {
	m_currentArtifact = new XmlDeploymentArtifact(m_artifactURL, m_artifactSize);
	}
	String value = text.trim();
	if (m_currentDirectiveKey != null && !value.equals("")) {
	m_currentArtifact.m_directives.put(m_currentDirectiveKey, value);
	}
	}

	XmlTag tag = XmlTag.asXmlTag(qName);
	// When we're ending the current tag, traverse up to its parent...
	if (!XmlTag.unknown.equals(tag) && (m_currentTag == tag)) {
	m_currentTag = tag.getParent();
	}

	// Invoke the callbacks for events we're interested in...
	if (XmlTag.version.equals(tag)) {
	if (m_currentVersion != null && !Version.emptyVersion.equals(m_currentVersion)) {
	// Let the version be handled (if needed)...
	handleVersion(m_currentVersion);
	}

	// Let the currentVersion field as-is! We want to reuse it for the artifacts...
	}
	else if (XmlTag.deploymentArtifact.equals(tag)) {
	if (m_currentArtifact != null) {
	// push out the current deployment artifact...
	handleArtifact(m_currentVersion, m_currentArtifact);
	}

	m_currentArtifact = null;
	m_artifactURL = null;
	m_artifactSize = -1L;
	}
	else if (XmlTag.directives.equals(tag)) {
	m_currentDirectiveKey = null;
	}
	}

	/**
	* Allows subclasses to handle the given version of a target's deployment package.
	* <p>
	* By default, this method does nothing.
	* </p>
	*
	* @param version
	* the version found, never <code>null</code>.
	*/
	protected void handleVersion(Version version) {
	// NO-op
	}

	/**
	* Allows subclasses to handle the given deployment artifact for the given version of the deployment package.
	* <p>
	* By default, this method does nothing.
	* </p>
	*
	* @param version
	* the version of the deployment package;
	* @param artifact
	* the deployment artifact itself.
	*/
	protected void handleArtifact(Version version, XmlDeploymentArtifact artifact) {
	// NO-op
	}

	/**
	* Parses the given text as {@link Version}.
	*
	* @param text
	* the text to parse as version, can not be <code>null</code>.
	* @return a {@link Version} if the given text represent a correct version, can be <code>null</code> in case of an
	* incorrect/empty version..
	*/
	protected final Version parseAsVersion(String text) {
	Version result = parseVersion(text);
	if (Version.emptyVersion.equals(result)) {
	return null;
	}
	return result;
	}

	/**
	* Helper class to store a pair of URL and directive, in which the directive may be empty.
	*/
	public static class XmlDeploymentArtifact {
	private final URL m_url;
	private final long m_size;
	private final Map<String, String> m_directives;

	private XmlDeploymentArtifact(URL url, long size) {
	m_url = url;
	m_size = size;
	m_directives = new HashMap<>();
	}

	public long getSize() {
	return m_size;
	}

	public URL getUrl() {
	return m_url;
	}

	public Map<String, String> getDirective() {
	return m_directives;
	}
	}

	/**
	* Defines the structure of our XML (only the parts we're interested in).
	*/
	public static enum XmlTag {
	targetID,
	version,
	attributes(targetID, version),
	url,
	size,
	directives,
	deploymentArtifact(url, size, directives),
	artifacts(deploymentArtifact),
	tags,
	deploymentversion(attributes, tags, artifacts),
	deploymentversions(deploymentversion),
	repository(deploymentversions),
	unknown(repository);

	private final XmlTag[] m_children;
	private XmlTag m_parent;

	private XmlTag(XmlTag... possibleChildren) {
	m_children = possibleChildren;
	// Update the children's parent...
	for (int i = 0; i < m_children.length; i++) {
	m_children[i].m_parent = this;
	}
	}

	/**
	* Returns the parent tag of this tag.
	*
	* @return a parent tag, can be <code>null</code>.
	*/
	public XmlTag getParent() {
	return m_parent;
	}

	/**
	* Returns whether the given XML tag is an expected child of this tag.
	*
	* @param xmlTag
	* the XML tag to test, cannot be <code>null</code>.
	* @return <code>true</code> if the given tag is an expected child of this tag, <code>false</code> otherwise.
	*/
	public boolean isExpectedChild(XmlTag xmlTag) {
	for (int i = 0; i < m_children.length; i++) {
	if (xmlTag.equals(m_children[i])) {
	return true;
	}
	}
	return false;
	}

	/**
	* Provides a "safe" way of representing the given tag name as instance of this enum. If the given name does not
	* represent a defined tag, "unknown" will be returned.
	*
	* @param name
	* the XML tag-name to represent as enum value, cannot be <code>null</code>.
	* @return a {@link XmlTag} representation of the given tag-name, never <code>null</code>.
	*/
	public static XmlTag asXmlTag(String name) {
	XmlTag[] values = { artifacts, attributes, deploymentArtifact, deploymentversion, deploymentversions, directives, repository, size, tags, targetID, url, version };
	for (int i = 0; i < values.length; i++) {
	if (values[i].name().equals(name)) {
	return values[i];
	}
	}
	return XmlTag.unknown;
	}
	}
	}