/*
* $Header: /home/cvs/jakarta-slide/webdavclient/clientlib/src/java/org/apache/webdav/lib/methods/LockMethod.java,v 1.6.2.2 2004/10/02 17:33:49 luetzkendorf Exp $
* $Revision: 1.6.2.2 $
* $Date: 2004/10/02 17:33:49 $
*
* ====================================================================
*
* Copyright 1999-2002 The Apache Software Foundation
*
* 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 org.apache.webdav.lib.methods;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.commons.httpclient.HttpConnection;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpState;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.util.URIUtil;
import org.apache.webdav.lib.WebdavState;
import org.apache.webdav.lib.properties.LockEntryProperty;
import org.apache.webdav.lib.util.DOMUtils;
import org.apache.webdav.lib.util.DOMWriter;
import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
/**
* Web resources can be locked to ensure that only one user is updating
* the resource at a time. Locking helps to prevent the "lost update" problem.
* There are two types of lock currently defined by the WebDAV specification:
* exclusive locks and shared locks.
*
* <p> Per the specification, a lock indicates that someone is updating the
* resource, (hence the lock is a "write lock"), although the specification
* notes that the the syntax is extensible, and permits the eventual creation
* of locking for other access types.
*
* <h3>Shared and Exclusive Locks</h3>
*
* <p> The most basic form of lock is an <em>exclusive lock</em>. This is a
* lock where the access right in question is only granted to a single client.
* The need for this arbitration results from a desire to avoid having to merge
* results. However, there are times when the goal of a lock is not to exclude
* others from exercising an access right but rather to provide a mechanism for
* principals to indicate that they intend to exercise their access rights.
* <em>Shared locks</em> are provided for this case. A shared lock allows
* multiple clients to receive a lock. Hence any user with appropriate
* access can get the lock.
*
* <p> With shared locks there are two trust sets that affect a resource.
* The first trust set is created by access permissions. Principals who are
* trusted, for example, may have permission to write to the resource. Among
* those who have access permission to write to the resource, the set of
* principals who have taken out a shared lock also must trust each other,
* creating a (typically) smaller trust set within the access permission write
* set.
*
* <h3>Lock Compatibility</h3>
*
* <p> The following table indicates what happens if a new lock request
* is sent to a resource that is already locked: </p>
*
* <table border="1">
* <tr><th> </th><th colspan="2"> Lock Request </th></tr>
* <tr><th>Current Lock </th><th>Exclusive Lock </th><th>Shared Lock </th></tr>
* <tr><td>None </td><td>Success </td><td>Sucess </td></tr>
* <tr><td>Shared </td><td>Failure </td><td>Sucess </td></tr>
* <tr><td>Exclusive </td><td>Failure </td><td>Failure </td></tr>
* </table>
*
*/
public class LockMethod
extends XMLResponseMethodBase implements DepthSupport {
// -------------------------------------------------------------- Constants
public static final short SCOPE_EXCLUSIVE =
LockEntryProperty.SCOPE_EXCLUSIVE;
public static final short SCOPE_SHARED = LockEntryProperty.SCOPE_SHARED;
public static final short TYPE_WRITE = LockEntryProperty.TYPE_WRITE;
// The timeout value for TimeType "Second" MUST NOT be greater than 2^32-1.
public static final int TIMEOUT_INFINITY = Integer.MAX_VALUE;
// ----------------------------------------------------- Instance Variables
/**
* The scope of lock we're requesting. The default scope is
* SCOPE_EXCLUSIVE.
*/
private short scope = SCOPE_EXCLUSIVE;
/**
* Depth.
*/
private int depth = DEPTH_INFINITY;
/**
* Opaque token of the lock we're trying to refresh.
*/
private String refreshOpaqueToken = null;
/**
* Lock timeout.
*/
private int timeout = TIMEOUT_INFINITY;
/**
* Lock owner.
*/
private String owner = null;
/**
* Lock token.
*/
private String lockToken = null;
private boolean typeTransaction = false;
// ----------------------------------------------------------- Constructors
/**
* Creates a lock method that can <em>start a transaction</em> when server supports
* them in a
* <a href="http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wss/wss/_webdav_lock.asp">MS like style</a>.
* The transacion handle of the started transaction will be returned as the lock token.
* To let subsequent requests participate in the transaction add a
* <code>Transaction</code> header with the lock token as value. You will have to enclose it in '<' and '>' just
* like ordinary lock tokens.
* <br><br>
* To either commit or abort the transaction
* use {@link UnlockMethod}.
*
* @param path any path inside Slide's scope
* @param owner of this transaction
* @param timeout timeout of this transaction
* @param isTransaction <code>true</code> when this method is used to starte a transaction
*
*/
public LockMethod(String path, String owner, int timeout, boolean isTransaction) {
this(path);
setOwner(owner);
setTimeout(timeout);
setTypeTransaction(isTransaction);
}
/**
* Method constructor.
*/
public LockMethod() {
}
/**
* Method constructor.
*/
public LockMethod(String path) {
super(path);
}
/**
* Method constructor.
*/
public LockMethod(String path, String refreshOpaqueToken, int timeout) {
this(path);
this.refreshOpaqueToken = refreshOpaqueToken;
setTimeout(timeout);
}
/**
* Method constructor.
*/
public LockMethod(String path, String owner, short scope, int timeout) {
this(path);
setOwner(owner);
setScope(scope);
setTimeout(timeout);
}
/**
* Method constructor.
* @deprecated The timeout value MUST NOT be greater than 2^32-1.
*/
public LockMethod(String path, String refreshOpaqueToken, long timeout) {
this(path, refreshOpaqueToken, (int) timeout);
}
/**
* Method constructor.
* @deprecated The timeout value MUST NOT be greater than 2^32-1.
*/
public LockMethod(String path, String owner, short scope, long timeout) {
this(path, owner, scope, (int) timeout);
}
// ------------------------------------------------------------- Properties
/**
* Set a header value, redirecting the special cases of Depth and Time headers
* to {@link #setDepth} and {@link #setTimeout} as appropriate.
*
* @param headerName Header name
* @param headerValue Header value
*/
public void setRequestHeader(String headerName, String headerValue) {
if (headerName.equalsIgnoreCase("Depth")){
int depth = -1;
if (headerValue.equals("0")){
depth = DEPTH_0;
}
if (headerValue.equals("1")){
depth = DEPTH_1;
}
else if (headerValue.equalsIgnoreCase("infinity")){
depth = DEPTH_INFINITY;
}
setDepth(depth);
}
else if(headerName.equalsIgnoreCase("Timeout")){
if (headerValue.startsWith("Second-"))
headerValue = headerValue.substring("Second-".length());
try {
setTimeout(Integer.parseInt(headerValue));
} catch (NumberFormatException e) {
}
}
else if(headerName.equalsIgnoreCase("Owner")){
setOwner(headerValue);
}
else{
super.setRequestHeader(headerName, headerValue);
}
}
public boolean isTypeTransaction() {
return typeTransaction;
}
public void setTypeTransaction(boolean typeTransaction) {
this.typeTransaction = typeTransaction;
}
/**
* Depth setter.
*
* @param depth New depth value
*/
public void setDepth(int depth) {
checkNotUsed();
if (depth != DEPTH_0 && depth != DEPTH_INFINITY) {
throw new IllegalArgumentException
("invalid depth value for lock method " + depth);
}
this.depth = depth;
}
/**
* Depth getter.
*
* @return int depth value
*/
public int getDepth() {
return depth;
}
public String getLockToken() {
checkUsed();
return this.lockToken;
}
public boolean isRefresh() {
return !((this.refreshOpaqueToken == null ) ||
(this.refreshOpaqueToken.equals("")));
}
public short getScope() {
return this.scope;
}
/**
* Sets the owner of the lock. This method provides only "basic" owner
* information. Thus, <code>setOwner("Jezebel Lipshitz")</code> will
* produce an <code>owner</code> element in the request document like this:
*
* <pre>
* <D:owner>Jezebel Lipshitz</D:owner>
* </pre>
*
* <p> Examples in the Webdav specification suggest that one can use
* e-mail addresses, home page URLs, or other information; this
* implementation doesn't handle any of that.
*/
public void setOwner(String owner) {
checkNotUsed();
this.owner = owner;
}
/** Return the owner of the lock as reported by the server. */
public String getOwner() {
return owner;
}
public void setScope(short scope) {
checkNotUsed();
if (scope != SCOPE_SHARED && scope != SCOPE_EXCLUSIVE) {
throw new IllegalArgumentException("invalid scope value");
}
this.scope = scope;
}
/**
* get the timeout value.
*
* @return timeout
*/
public int getTimeout() {
return this.timeout;
}
/**
* Set the timeout value.
*/
public void setTimeout(int timeout) {
checkNotUsed();
if (timeout < 0) {
throw new IllegalArgumentException("invalid timeout value: " +
timeout);
}
this.timeout = timeout;
}
/**
* Set the timeout value.
* @deprecated The timeout value MUST NOT be greater than 2^32-1.
*/
public void setTimeout(long timeout) {
setTimeout((int) timeout);
}
// --------------------------------------------------- WebdavMethod Methods
public String getName() {
return "LOCK";
}
public void recycle() {
super.recycle();
this.refreshOpaqueToken = null;
this.depth = DEPTH_INFINITY;
this.scope = SCOPE_EXCLUSIVE;
this.timeout = TIMEOUT_INFINITY;
this.typeTransaction = false;
}
/**
* Generate additional headers needed by the request.
*
* @param state State token
* @param conn The connection being used for the request.
*/
public void addRequestHeaders(HttpState state, HttpConnection conn)
throws IOException, HttpException {
// set the default utf-8 encoding, if not already present
if (getRequestHeader("Content-Type") == null ) super.setRequestHeader("Content-Type", "text/xml; charset=utf-8");
super.addRequestHeaders(state, conn);
switch (depth) {
case DEPTH_0:
super.setRequestHeader("Depth", "0");
break;
case DEPTH_INFINITY:
super.setRequestHeader("Depth", "infinity");
break;
default:
}
if (timeout == TIMEOUT_INFINITY) {
super.setRequestHeader("Timeout", "Infinite, Second-" + TIMEOUT_INFINITY);
} else {
super.setRequestHeader("Timeout", "Second-" + timeout);
}
if (isRefresh()) {
super.setRequestHeader("If", "(<" + refreshOpaqueToken + ">)");
}
}
/**
* DAV requests that contain a body must override this function to
* generate that body.
*
* <p>The default behavior simply returns an empty body.</p>
*/
protected String generateRequestBody() {
String result = "";
if (!isRefresh()) {
if (this.owner == null || this.owner.equals("")) {
throw new IllegalStateException
("The owner property has not been set");
}
try {
DocumentBuilderFactory factory =
DocumentBuilderFactory.newInstance();
DocumentBuilder builder = factory.newDocumentBuilder();
Document document = builder.newDocument();
Element lockinfo = document.createElement("DAV:lockinfo");
document.appendChild(lockinfo);
lockinfo.setAttribute("xmlns:DAV", "DAV:");
Element lockscope = document.createElement("DAV:lockscope");
lockinfo.appendChild(lockscope);
if (this.scope == SCOPE_EXCLUSIVE) {
Element exclusive =
document.createElement("DAV:exclusive");
lockscope.appendChild(exclusive);
} else {
Element shared = document.createElement("DAV:shared");
lockscope.appendChild(shared);
}
Element locktype = document.createElement("DAV:locktype");
lockinfo.appendChild(locktype);
if (typeTransaction) {
Element transaction = document.createElement("DAV:transaction");
locktype.appendChild(transaction);
} else {
Element write = document.createElement("DAV:write");
locktype.appendChild(write);
}
Element owner = document.createElement("DAV:owner");
lockinfo.appendChild(owner);
Text text = document.createTextNode(this.owner);
owner.appendChild(text);
StringWriter stringWriter = new StringWriter();
DOMWriter domWriter = new DOMWriter(stringWriter, false);
domWriter.print(document);
result = stringWriter.getBuffer().toString();
} catch (DOMException e) {
} catch (ParserConfigurationException e) {
}
}
return result;
}
/**
* Parse response.
*
* @param input Input stream
*/
public void parseResponse(InputStream input, HttpState state, HttpConnection conn)
throws IOException, HttpException {
int status = getStatusLine().getStatusCode();
if (status == HttpStatus.SC_OK ||
status == HttpStatus.SC_CREATED ||
status == HttpStatus.SC_MULTI_STATUS ) {
parseXMLResponse(input);
NodeList list = getResponseDocument().getDocumentElement()
.getElementsByTagNameNS("DAV:", "locktoken");
if (list.getLength() == 1) {
Element locktoken = (Element) list.item(0);
NodeList list2 = locktoken.getElementsByTagNameNS("DAV:", "href");
if (list2.getLength() == 1) {
this.lockToken = DOMUtils.getTextValue(list2.item(0));
if (state instanceof WebdavState) {
/*
* lockMethod/unlockMethod take unescaped URIs but LockMathod.getPath()
* func returns an escaped URI so searching for the lock by path name in
* the state object doesn't work. Convert escaped back to unescaped.
*/
((WebdavState) state).addLock(URIUtil.decode(getPath()),
this.lockToken);
}
}
}
list = getResponseDocument().getDocumentElement()
.getElementsByTagNameNS("DAV:", "owner");
if (list.getLength() == 1) {
Element owner = (Element)list.item(0);
this.owner = DOMUtils.getTextValue(owner);
}
}
}
}