java/org/apache/catalina/core/ApplicationPushBuilder.java - tomcat - 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.catalina.core;

 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Enumeration;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Set;

 import javax.servlet.SessionTrackingMode;
 import javax.servlet.http.Cookie;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpSession;
 import javax.servlet.http.PushBuilder;

 import org.apache.catalina.Context;
 import org.apache.catalina.authenticator.AuthenticatorBase;
 import org.apache.catalina.connector.Request;
 import org.apache.catalina.util.SessionConfig;
 import org.apache.coyote.ActionCode;
 import org.apache.tomcat.util.buf.HexUtils;
 import org.apache.tomcat.util.buf.MessageBytes;
 import org.apache.tomcat.util.collections.CaseInsensitiveKeyMap;
 import org.apache.tomcat.util.http.CookieProcessor;
 import org.apache.tomcat.util.http.parser.HttpParser;
 import org.apache.tomcat.util.res.StringManager;

 public class ApplicationPushBuilder implements PushBuilder {

     private static final StringManager sm = StringManager.getManager(ApplicationPushBuilder.class);
     private static final Set<String> DISALLOWED_METHODS = new HashSet<>();

     static {
         DISALLOWED_METHODS.add("POST");
         DISALLOWED_METHODS.add("PUT");
         DISALLOWED_METHODS.add("DELETE");
         DISALLOWED_METHODS.add("CONNECT");
         DISALLOWED_METHODS.add("OPTIONS");
         DISALLOWED_METHODS.add("TRACE");
     }

     private final HttpServletRequest baseRequest;
     private final Request catalinaRequest;
     private final org.apache.coyote.Request coyoteRequest;
     private final String sessionCookieName;
     private final String sessionPathParameterName;
     private final boolean addSessionCookie;
     private final boolean addSessionPathParameter;

     private final Map<String,List<String>> headers = new CaseInsensitiveKeyMap<>();
     private final List<Cookie> cookies = new ArrayList<>();
     private String method = "GET";
     private String path;
     private String queryString;
     private String sessionId;
     private String userName;


     public ApplicationPushBuilder(Request catalinaRequest, HttpServletRequest request) {

         baseRequest = request;
         this.catalinaRequest = catalinaRequest;
         coyoteRequest = catalinaRequest.getCoyoteRequest();

         // Populate the initial list of HTTP headers
         Enumeration<String> headerNames = request.getHeaderNames();
         while (headerNames.hasMoreElements()) {
             String headerName = headerNames.nextElement();
             List<String> values = new ArrayList<>();
             headers.put(headerName, values);
             Enumeration<String> headerValues = request.getHeaders(headerName);
             while (headerValues.hasMoreElements()) {
                 values.add(headerValues.nextElement());
             }
         }

         // Remove the headers
         headers.remove("if-match");
         headers.remove("if-none-match");
         headers.remove("if-modified-since");
         headers.remove("if-unmodified-since");
         headers.remove("if-range");
         headers.remove("range");
         headers.remove("expect");
         headers.remove("authorization");
         headers.remove("referer");
         // Also remove the cookie header since it will be regenerated
         headers.remove("cookie");

         // set the referer header
         StringBuffer referer = request.getRequestURL();
         if (request.getQueryString() != null) {
             referer.append('?');
             referer.append(request.getQueryString());
         }
         addHeader("referer", referer.toString());

         // Session
         Context context = catalinaRequest.getContext();
         sessionCookieName = SessionConfig.getSessionCookieName(context);
         sessionPathParameterName = SessionConfig.getSessionUriParamName(context);

         HttpSession session = request.getSession(false);
         if (session != null) {
             sessionId = session.getId();
         }
         if (sessionId == null) {
             sessionId = request.getRequestedSessionId();
         }
         if (!request.isRequestedSessionIdFromCookie() && !request.isRequestedSessionIdFromURL() &&
                 sessionId != null) {
             Set<SessionTrackingMode> sessionTrackingModes =
                     request.getServletContext().getEffectiveSessionTrackingModes();
             addSessionCookie = sessionTrackingModes.contains(SessionTrackingMode.COOKIE);
             addSessionPathParameter = sessionTrackingModes.contains(SessionTrackingMode.URL);
         } else {
             addSessionCookie = request.isRequestedSessionIdFromCookie();
             addSessionPathParameter = request.isRequestedSessionIdFromURL();
         }

         // Cookies
         if (request.getCookies() != null) {
             cookies.addAll(Arrays.asList(request.getCookies()));
         }
         for (Cookie responseCookie : catalinaRequest.getResponse().getCookies()) {
             if (responseCookie.getMaxAge() < 0) {
                 // Path information not available so can only remove based on
                 // name.
                 cookies.removeIf(cookie -> cookie.getName().equals(responseCookie.getName()));
             } else {
                 cookies.add(new Cookie(responseCookie.getName(), responseCookie.getValue()));
             }
         }
         List<String> cookieValues = new ArrayList<>(1);
         cookieValues.add(generateCookieHeader(cookies,
                 catalinaRequest.getContext().getCookieProcessor()));
         headers.put("cookie", cookieValues);

         // Authentication
         if (catalinaRequest.getPrincipal() != null) {
             if ((session == null) || catalinaRequest.getSessionInternal(false).getPrincipal() == null
                     || !(context.getAuthenticator() instanceof AuthenticatorBase)
                     || !((AuthenticatorBase) context.getAuthenticator()).getCache()) {
                 // Set a username only if there is no session cache for the principal
                 userName = catalinaRequest.getPrincipal().getName();
             }
             setHeader("authorization", "x-push");
         }
     }

     @Override
     public PushBuilder path(String path) {
         if (path.startsWith("/")) {
             this.path = path;
         } else {
             String contextPath = baseRequest.getContextPath();
             int len = contextPath.length() + path.length() + 1;
             StringBuilder sb = new StringBuilder(len);
             sb.append(contextPath);
             sb.append('/');
             sb.append(path);
             this.path = sb.toString();
         }
         return this;
     }


     @Override
     public String getPath() {
         return path;
     }


     @Override
     public PushBuilder method(String method) {
         String upperMethod = method.trim().toUpperCase(Locale.ENGLISH);
         if (DISALLOWED_METHODS.contains(upperMethod) || upperMethod.length() == 0) {
             throw new IllegalArgumentException(
                     sm.getString("applicationPushBuilder.methodInvalid", upperMethod));
         }
         // Check a token was supplied
         for (char c : upperMethod.toCharArray()) {
             if (!HttpParser.isToken(c)) {
                 throw new IllegalArgumentException(
                         sm.getString("applicationPushBuilder.methodNotToken", upperMethod));
             }
         }
         this.method = method;
         return this;
     }


     @Override
     public String getMethod() {
         return method;
     }


     @Override
     public PushBuilder queryString(String queryString) {
         this.queryString = queryString;
         return this;
     }


     @Override
     public String getQueryString() {
         return queryString;
     }


     @Override
     public PushBuilder sessionId(String sessionId) {
         this.sessionId = sessionId;
         return this;
     }


     @Override
     public String getSessionId() {
         return sessionId;
     }


     @Override
     public PushBuilder addHeader(String name, String value) {
         List<String> values = headers.get(name);
         if (values == null) {
             values = new ArrayList<>();
             headers.put(name, values);
         }
         values.add(value);

         return this;
     }


     @Override
     public PushBuilder setHeader(String name, String value) {
         List<String> values = headers.get(name);
         if (values == null) {
             values = new ArrayList<>();
             headers.put(name, values);
         } else {
             values.clear();
         }
         values.add(value);

         return this;
     }


     @Override
     public PushBuilder removeHeader(String name) {
         headers.remove(name);

         return this;
     }


     @Override
     public Set<String> getHeaderNames() {
         return Collections.unmodifiableSet(headers.keySet());
     }


     @Override
     public String getHeader(String name) {
         List<String> values = headers.get(name);
         if (values == null) {
             return null;
         } else {
             return values.get(0);
         }
     }


     @Override
     public void push() {
         if (path == null) {
             throw new IllegalStateException(sm.getString("pushBuilder.noPath"));
         }

         org.apache.coyote.Request pushTarget = new org.apache.coyote.Request();

         pushTarget.method().setString(method);
         // The next three are implied by the Javadoc getPath()
         pushTarget.serverName().setString(baseRequest.getServerName());
         pushTarget.setServerPort(baseRequest.getServerPort());
         pushTarget.scheme().setString(baseRequest.getScheme());

         // Copy headers
         for (Map.Entry<String,List<String>> header : headers.entrySet()) {
             for (String value : header.getValue()) {
                 pushTarget.getMimeHeaders().addValue(header.getKey()).setString(value);
             }
         }

         // Path and query string
         int queryIndex = path.indexOf('?');
         String pushPath;
         String pushQueryString = null;
         if (queryIndex > -1) {
             pushPath = path.substring(0, queryIndex);
             if (queryIndex + 1 < path.length()) {
                 pushQueryString = path.substring(queryIndex + 1);
             }
         } else {
             pushPath = path;
         }

         // Session ID (do this before setting the path since it may change it)
         if (sessionId != null) {
             if (addSessionPathParameter) {
                 pushPath = pushPath + ";" + sessionPathParameterName + "=" + sessionId;
                 pushTarget.addPathParameter(sessionPathParameterName, sessionId);
             }
             if (addSessionCookie) {
                 String sessionCookieHeader = sessionCookieName + "=" + sessionId;
                 MessageBytes mb = pushTarget.getMimeHeaders().getValue("cookie");
                 if (mb == null) {
                     mb = pushTarget.getMimeHeaders().addValue("cookie");
                     mb.setString(sessionCookieHeader);
                 } else {
                     mb.setString(mb.getString() + ";" + sessionCookieHeader);
                 }
             }
         }

         // Undecoded path - just %nn encoded
         pushTarget.requestURI().setString(pushPath);
         pushTarget.decodedURI().setString(decode(pushPath,
                 catalinaRequest.getConnector().getURICharset()));

         // Query string
         if (pushQueryString == null && queryString != null) {
             pushTarget.queryString().setString(queryString);
         } else if (pushQueryString != null && queryString == null) {
             pushTarget.queryString().setString(pushQueryString);
         } else if (pushQueryString != null && queryString != null) {
             pushTarget.queryString().setString(pushQueryString + "&" +queryString);
         }

         // Authorization
         if (userName != null) {
             pushTarget.getRemoteUser().setString(userName);
             pushTarget.setRemoteUserNeedsAuthorization(true);
         }

         coyoteRequest.action(ActionCode.PUSH_REQUEST, pushTarget);

         // Reset for next call to this method
         path = null;
         headers.remove("if-none-match");
         headers.remove("if-modified-since");
     }


     // Package private so it can be tested. charsetName must be in lower case.
     static String decode(String input, Charset charset) {
         int start = input.indexOf('%');
         int end = 0;

         // Shortcut
         if (start == -1) {
             return input;
         }

         StringBuilder result = new StringBuilder(input.length());
         while (start != -1) {
             // Found the start of a %nn sequence. Copy everything from the last
             // end to this start to the output.
             result.append(input.substring(end, start));
             // Advance the end 3 characters: %nn
             end = start + 3;
             while (end <input.length() && input.charAt(end) == '%') {
                 end += 3;
             }
             result.append(decodePercentSequence(input.substring(start, end), charset));
             start = input.indexOf('%', end);
         }
         // Append the remaining text
         result.append(input.substring(end));

         return result.toString();
     }


     private static String decodePercentSequence(String sequence, Charset charset) {
         byte[] bytes = new byte[sequence.length()/3];
         for (int i = 0; i < bytes.length; i += 3) {
             bytes[i] = (byte) ((HexUtils.getDec(sequence.charAt(1 + 3 * i)) << 4) +
                     HexUtils.getDec(sequence.charAt(2 + 3 * i)));
         }

         return new String(bytes, charset);
     }


     private static String generateCookieHeader(List<Cookie> cookies, CookieProcessor cookieProcessor) {
         StringBuilder result = new StringBuilder();
         boolean first = true;
         for (Cookie cookie : cookies) {
             if (first) {
                 first = false;
             } else {
                 result.append(';');
             }
             // The cookie header value generated by the CookieProcessor was
             // originally intended for the Set-Cookie header on the response.
             // However, if passed a Cookie with just a name and value set it
             // will generate an appropriate header for the Cookie header on the
             // pushed request.
             result.append(cookieProcessor.generateHeader(cookie, null));
         }
         return result.toString();
     }
 }
	/*
	* 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.catalina.core;

	import java.nio.charset.Charset;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.Collections;
	import java.util.Enumeration;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Locale;
	import java.util.Map;
	import java.util.Set;

	import javax.servlet.SessionTrackingMode;
	import javax.servlet.http.Cookie;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpSession;
	import javax.servlet.http.PushBuilder;

	import org.apache.catalina.Context;
	import org.apache.catalina.authenticator.AuthenticatorBase;
	import org.apache.catalina.connector.Request;
	import org.apache.catalina.util.SessionConfig;
	import org.apache.coyote.ActionCode;
	import org.apache.tomcat.util.buf.HexUtils;
	import org.apache.tomcat.util.buf.MessageBytes;
	import org.apache.tomcat.util.collections.CaseInsensitiveKeyMap;
	import org.apache.tomcat.util.http.CookieProcessor;
	import org.apache.tomcat.util.http.parser.HttpParser;
	import org.apache.tomcat.util.res.StringManager;

	public class ApplicationPushBuilder implements PushBuilder {

	private static final StringManager sm = StringManager.getManager(ApplicationPushBuilder.class);
	private static final Set<String> DISALLOWED_METHODS = new HashSet<>();

	static {
	DISALLOWED_METHODS.add("POST");
	DISALLOWED_METHODS.add("PUT");
	DISALLOWED_METHODS.add("DELETE");
	DISALLOWED_METHODS.add("CONNECT");
	DISALLOWED_METHODS.add("OPTIONS");
	DISALLOWED_METHODS.add("TRACE");
	}

	private final HttpServletRequest baseRequest;
	private final Request catalinaRequest;
	private final org.apache.coyote.Request coyoteRequest;
	private final String sessionCookieName;
	private final String sessionPathParameterName;
	private final boolean addSessionCookie;
	private final boolean addSessionPathParameter;

	private final Map<String,List<String>> headers = new CaseInsensitiveKeyMap<>();
	private final List<Cookie> cookies = new ArrayList<>();
	private String method = "GET";
	private String path;
	private String queryString;
	private String sessionId;
	private String userName;


	public ApplicationPushBuilder(Request catalinaRequest, HttpServletRequest request) {

	baseRequest = request;
	this.catalinaRequest = catalinaRequest;
	coyoteRequest = catalinaRequest.getCoyoteRequest();

	// Populate the initial list of HTTP headers
	Enumeration<String> headerNames = request.getHeaderNames();
	while (headerNames.hasMoreElements()) {
	String headerName = headerNames.nextElement();
	List<String> values = new ArrayList<>();
	headers.put(headerName, values);
	Enumeration<String> headerValues = request.getHeaders(headerName);
	while (headerValues.hasMoreElements()) {
	values.add(headerValues.nextElement());
	}
	}

	// Remove the headers
	headers.remove("if-match");
	headers.remove("if-none-match");
	headers.remove("if-modified-since");
	headers.remove("if-unmodified-since");
	headers.remove("if-range");
	headers.remove("range");
	headers.remove("expect");
	headers.remove("authorization");
	headers.remove("referer");
	// Also remove the cookie header since it will be regenerated
	headers.remove("cookie");

	// set the referer header
	StringBuffer referer = request.getRequestURL();
	if (request.getQueryString() != null) {
	referer.append('?');
	referer.append(request.getQueryString());
	}
	addHeader("referer", referer.toString());

	// Session
	Context context = catalinaRequest.getContext();
	sessionCookieName = SessionConfig.getSessionCookieName(context);
	sessionPathParameterName = SessionConfig.getSessionUriParamName(context);

	HttpSession session = request.getSession(false);
	if (session != null) {
	sessionId = session.getId();
	}
	if (sessionId == null) {
	sessionId = request.getRequestedSessionId();
	}
	if (!request.isRequestedSessionIdFromCookie() && !request.isRequestedSessionIdFromURL() &&
	sessionId != null) {
	Set<SessionTrackingMode> sessionTrackingModes =
	request.getServletContext().getEffectiveSessionTrackingModes();
	addSessionCookie = sessionTrackingModes.contains(SessionTrackingMode.COOKIE);
	addSessionPathParameter = sessionTrackingModes.contains(SessionTrackingMode.URL);
	} else {
	addSessionCookie = request.isRequestedSessionIdFromCookie();
	addSessionPathParameter = request.isRequestedSessionIdFromURL();
	}

	// Cookies
	if (request.getCookies() != null) {
	cookies.addAll(Arrays.asList(request.getCookies()));
	}
	for (Cookie responseCookie : catalinaRequest.getResponse().getCookies()) {
	if (responseCookie.getMaxAge() < 0) {
	// Path information not available so can only remove based on
	// name.
	cookies.removeIf(cookie -> cookie.getName().equals(responseCookie.getName()));
	} else {
	cookies.add(new Cookie(responseCookie.getName(), responseCookie.getValue()));
	}
	}
	List<String> cookieValues = new ArrayList<>(1);
	cookieValues.add(generateCookieHeader(cookies,
	catalinaRequest.getContext().getCookieProcessor()));
	headers.put("cookie", cookieValues);

	// Authentication
	if (catalinaRequest.getPrincipal() != null) {
	if ((session == null) \|\| catalinaRequest.getSessionInternal(false).getPrincipal() == null
	\|\| !(context.getAuthenticator() instanceof AuthenticatorBase)
	\|\| !((AuthenticatorBase) context.getAuthenticator()).getCache()) {
	// Set a username only if there is no session cache for the principal
	userName = catalinaRequest.getPrincipal().getName();
	}
	setHeader("authorization", "x-push");
	}
	}

	@Override
	public PushBuilder path(String path) {
	if (path.startsWith("/")) {
	this.path = path;
	} else {
	String contextPath = baseRequest.getContextPath();
	int len = contextPath.length() + path.length() + 1;
	StringBuilder sb = new StringBuilder(len);
	sb.append(contextPath);
	sb.append('/');
	sb.append(path);
	this.path = sb.toString();
	}
	return this;
	}


	@Override
	public String getPath() {
	return path;
	}


	@Override
	public PushBuilder method(String method) {
	String upperMethod = method.trim().toUpperCase(Locale.ENGLISH);
	if (DISALLOWED_METHODS.contains(upperMethod) \|\| upperMethod.length() == 0) {
	throw new IllegalArgumentException(
	sm.getString("applicationPushBuilder.methodInvalid", upperMethod));
	}
	// Check a token was supplied
	for (char c : upperMethod.toCharArray()) {
	if (!HttpParser.isToken(c)) {
	throw new IllegalArgumentException(
	sm.getString("applicationPushBuilder.methodNotToken", upperMethod));
	}
	}
	this.method = method;
	return this;
	}


	@Override
	public String getMethod() {
	return method;
	}


	@Override
	public PushBuilder queryString(String queryString) {
	this.queryString = queryString;
	return this;
	}


	@Override
	public String getQueryString() {
	return queryString;
	}


	@Override
	public PushBuilder sessionId(String sessionId) {
	this.sessionId = sessionId;
	return this;
	}


	@Override
	public String getSessionId() {
	return sessionId;
	}


	@Override
	public PushBuilder addHeader(String name, String value) {
	List<String> values = headers.get(name);
	if (values == null) {
	values = new ArrayList<>();
	headers.put(name, values);
	}
	values.add(value);

	return this;
	}


	@Override
	public PushBuilder setHeader(String name, String value) {
	List<String> values = headers.get(name);
	if (values == null) {
	values = new ArrayList<>();
	headers.put(name, values);
	} else {
	values.clear();
	}
	values.add(value);

	return this;
	}


	@Override
	public PushBuilder removeHeader(String name) {
	headers.remove(name);

	return this;
	}


	@Override
	public Set<String> getHeaderNames() {
	return Collections.unmodifiableSet(headers.keySet());
	}


	@Override
	public String getHeader(String name) {
	List<String> values = headers.get(name);
	if (values == null) {
	return null;
	} else {
	return values.get(0);
	}
	}


	@Override
	public void push() {
	if (path == null) {
	throw new IllegalStateException(sm.getString("pushBuilder.noPath"));
	}

	org.apache.coyote.Request pushTarget = new org.apache.coyote.Request();

	pushTarget.method().setString(method);
	// The next three are implied by the Javadoc getPath()
	pushTarget.serverName().setString(baseRequest.getServerName());
	pushTarget.setServerPort(baseRequest.getServerPort());
	pushTarget.scheme().setString(baseRequest.getScheme());

	// Copy headers
	for (Map.Entry<String,List<String>> header : headers.entrySet()) {
	for (String value : header.getValue()) {
	pushTarget.getMimeHeaders().addValue(header.getKey()).setString(value);
	}
	}

	// Path and query string
	int queryIndex = path.indexOf('?');
	String pushPath;
	String pushQueryString = null;
	if (queryIndex > -1) {
	pushPath = path.substring(0, queryIndex);
	if (queryIndex + 1 < path.length()) {
	pushQueryString = path.substring(queryIndex + 1);
	}
	} else {
	pushPath = path;
	}

	// Session ID (do this before setting the path since it may change it)
	if (sessionId != null) {
	if (addSessionPathParameter) {
	pushPath = pushPath + ";" + sessionPathParameterName + "=" + sessionId;
	pushTarget.addPathParameter(sessionPathParameterName, sessionId);
	}
	if (addSessionCookie) {
	String sessionCookieHeader = sessionCookieName + "=" + sessionId;
	MessageBytes mb = pushTarget.getMimeHeaders().getValue("cookie");
	if (mb == null) {
	mb = pushTarget.getMimeHeaders().addValue("cookie");
	mb.setString(sessionCookieHeader);
	} else {
	mb.setString(mb.getString() + ";" + sessionCookieHeader);
	}
	}
	}

	// Undecoded path - just %nn encoded
	pushTarget.requestURI().setString(pushPath);
	pushTarget.decodedURI().setString(decode(pushPath,
	catalinaRequest.getConnector().getURICharset()));

	// Query string
	if (pushQueryString == null && queryString != null) {
	pushTarget.queryString().setString(queryString);
	} else if (pushQueryString != null && queryString == null) {
	pushTarget.queryString().setString(pushQueryString);
	} else if (pushQueryString != null && queryString != null) {
	pushTarget.queryString().setString(pushQueryString + "&" +queryString);
	}

	// Authorization
	if (userName != null) {
	pushTarget.getRemoteUser().setString(userName);
	pushTarget.setRemoteUserNeedsAuthorization(true);
	}

	coyoteRequest.action(ActionCode.PUSH_REQUEST, pushTarget);

	// Reset for next call to this method
	path = null;
	headers.remove("if-none-match");
	headers.remove("if-modified-since");
	}


	// Package private so it can be tested. charsetName must be in lower case.
	static String decode(String input, Charset charset) {
	int start = input.indexOf('%');
	int end = 0;

	// Shortcut
	if (start == -1) {
	return input;
	}

	StringBuilder result = new StringBuilder(input.length());
	while (start != -1) {
	// Found the start of a %nn sequence. Copy everything from the last
	// end to this start to the output.
	result.append(input.substring(end, start));
	// Advance the end 3 characters: %nn
	end = start + 3;
	while (end <input.length() && input.charAt(end) == '%') {
	end += 3;
	}
	result.append(decodePercentSequence(input.substring(start, end), charset));
	start = input.indexOf('%', end);
	}
	// Append the remaining text
	result.append(input.substring(end));

	return result.toString();
	}


	private static String decodePercentSequence(String sequence, Charset charset) {
	byte[] bytes = new byte[sequence.length()/3];
	for (int i = 0; i < bytes.length; i += 3) {
	bytes[i] = (byte) ((HexUtils.getDec(sequence.charAt(1 + 3 * i)) << 4) +
	HexUtils.getDec(sequence.charAt(2 + 3 * i)));
	}

	return new String(bytes, charset);
	}


	private static String generateCookieHeader(List<Cookie> cookies, CookieProcessor cookieProcessor) {
	StringBuilder result = new StringBuilder();
	boolean first = true;
	for (Cookie cookie : cookies) {
	if (first) {
	first = false;
	} else {
	result.append(';');
	}
	// The cookie header value generated by the CookieProcessor was
	// originally intended for the Set-Cookie header on the response.
	// However, if passed a Cookie with just a name and value set it
	// will generate an appropriate header for the Cookie header on the
	// pushed request.
	result.append(cookieProcessor.generateHeader(cookie, null));
	}
	return result.toString();
	}
	}