/* Copyright (c) 2008 Google Inc.
*
* 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 com.google.gdata.client.http;
import com.google.gdata.util.common.xml.XmlWriter;
import com.google.gdata.client.AuthTokenFactory;
import com.google.gdata.client.GDataProtocol;
import com.google.gdata.client.Query;
import com.google.gdata.client.GDataProtocol.Header;
import com.google.gdata.client.Service.GDataRequest;
import com.google.gdata.client.Service.GDataRequestFactory;
import com.google.gdata.data.DateTime;
import com.google.gdata.data.ParseSource;
import com.google.gdata.util.AuthenticationException;
import com.google.gdata.util.ContentType;
import com.google.gdata.util.EntityTooLargeException;
import com.google.gdata.util.InvalidEntryException;
import com.google.gdata.util.LoggableInputStream;
import com.google.gdata.util.LoggableOutputStream;
import com.google.gdata.util.NoLongerAvailableException;
import com.google.gdata.util.NotAcceptableException;
import com.google.gdata.util.NotImplementedException;
import com.google.gdata.util.NotModifiedException;
import com.google.gdata.util.PreconditionFailedException;
import com.google.gdata.util.ResourceNotFoundException;
import com.google.gdata.util.ServiceException;
import com.google.gdata.util.ServiceForbiddenException;
import com.google.gdata.util.VersionConflictException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.ProtocolException;
import java.net.URL;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.zip.GZIPInputStream;
/**
* The HttpGDataRequest class provides a basic implementation of the
* <code>GDataRequest</code> interface over HTTP.
*
* @see GDataRequest
*/
public class HttpGDataRequest implements GDataRequest {
static final Logger logger =
Logger.getLogger(HttpGDataRequest.class.getName());
/**
* If this system property is set to <code>true</code>, the GData HTTP
* client library will use POST to send data to the associated GData service
* and will specify the actual method using the {@code METHOD_OVERRIDE_HEADER}
* HTTP header. This can be used as a workaround for HTTP proxies or gateways
* that do not handle PUT or DELETE HTTP methods properly. If the system
* property is <code>false</code>, the regular PUT and DELETE HTTP verbs
* will be used.
*/
public static final String METHOD_OVERRIDE_PROPERTY =
"com.google.gdata.UseMethodOverride";
/**
* Name of HTTP header containing the method name that overrides the normal
* HTTP method.
*
* @deprecated Use {@link GDataProtocol.Header#METHOD_OVERRIDE} instead
*/
public static final String METHOD_OVERRIDE_HEADER =
GDataProtocol.Header.METHOD_OVERRIDE;
/**
* The HttpGDataRequest.Factory class is a factory class for constructing
* new HttpGDataRequest instances.
*/
public static class Factory implements GDataRequestFactory {
protected HttpAuthToken authToken;
protected Map<String, String> headerMap
= new LinkedHashMap<String, String>();
protected Map<String, String> privateHeaderMap
= new LinkedHashMap<String, String>();
protected boolean useSsl = false;
public void setAuthToken(AuthTokenFactory.AuthToken authToken) {
if (authToken != null && !(authToken instanceof HttpAuthToken)) {
throw new IllegalArgumentException("Invalid token type");
}
setAuthToken((HttpAuthToken) authToken);
}
public void setAuthToken(HttpAuthToken authToken) {
this.authToken = authToken;
}
public void useSsl() {
this.useSsl = true;
}
private void extendHeaderMap(Map<String, String> headerMap,
String header, String value) {
if (value == null) {
headerMap.remove(header);
} else {
headerMap.put(header, value);
}
}
public void setHeader(String header, String value) {
extendHeaderMap(this.headerMap, header, value);
}
public void setPrivateHeader(String header, String value) {
extendHeaderMap(this.privateHeaderMap, header, value);
}
@SuppressWarnings("unused")
public GDataRequest getRequest(RequestType type,
URL requestUrl,
ContentType contentType)
throws IOException, ServiceException {
if (this.useSsl && !requestUrl.getProtocol().startsWith("https")) {
requestUrl = new URL(
requestUrl.toString().replaceFirst("http", "https"));
}
return new HttpGDataRequest(type, requestUrl, contentType,
authToken, headerMap, privateHeaderMap);
}
@SuppressWarnings("unused")
public GDataRequest getRequest(Query query, ContentType contentType)
throws IOException, ServiceException {
return getRequest(RequestType.QUERY, query.getUrl(), contentType);
}
}
/**
* Underlying HTTP connection to the GData service.
*/
protected HttpURLConnection httpConn;
/**
* The request URL provided by the client.
*/
protected URL requestUrl;
/**
* The GData request type.
*/
protected RequestType type;
/**
* Indicates whether request execution has taken place. Set to
* <code>true</code> if executed, <code>false</code> otherwise.
*/
protected boolean executed = false;
/**
* True if the request type expects input from the client.
*/
protected boolean expectsInput;
/**
* True if the request type returns output to the client.
*/
protected boolean hasOutput;
/**
* The connection timeout for this request. A value of -1 means no value has
* been configured (use JDK default timeout behavior).
*/
protected int connectTimeout = -1;
/**
* The read timeout for this request. A value of -1 means no value has been
* configured (use JDK default timeout behavior).
*/
protected int readTimeout = -1;
/**
* Constructs a new HttpGDataRequest instance of the specified RequestType,
* targeting the specified URL.
*
* @param type type of GDataRequest.
* @param requestUrl request target URL.
* @param contentType the content type of request/response data.
* @param headerMap a set of headers to be included in each request
* @param privateHeaderMap a set of headers to be included in each request
* @throws IOException on error initializating service connection.
*/
protected HttpGDataRequest(RequestType type, URL requestUrl,
ContentType contentType, HttpAuthToken authToken,
Map<String, String> headerMap, Map<String, String> privateHeaderMap)
throws IOException {
this.type = type;
this.requestUrl = requestUrl;
httpConn = getRequestConnection(requestUrl);
switch (type) {
case QUERY:
hasOutput = true;
break;
case INSERT:
case BATCH:
expectsInput = true;
hasOutput = true;
setMethod("POST");
setHeader("Content-Type", contentType.toString());
break;
case UPDATE:
expectsInput = true;
hasOutput = true;
if (Boolean.getBoolean(METHOD_OVERRIDE_PROPERTY)) {
setMethod("POST");
setHeader(Header.METHOD_OVERRIDE, "PUT");
} else {
setMethod("PUT");
}
setHeader("Content-Type", contentType.toString());
break;
case DELETE:
if (Boolean.getBoolean(METHOD_OVERRIDE_PROPERTY)) {
setMethod("POST");
setHeader(Header.METHOD_OVERRIDE, "DELETE");
} else {
setMethod("DELETE");
}
setHeader("Content-Length", "0"); // no data to POST
break;
default:
throw new UnsupportedOperationException("Unknown request type:" + type);
}
if (authToken != null) {
// NOTE: Do not use setHeader() here, authorization should never be
// logged.
String authHeader =
authToken.getAuthorizationHeader(requestUrl, httpConn
.getRequestMethod());
setPrivateHeader("Authorization", authHeader);
}
if (headerMap != null) {
for (Map.Entry<String, String> e : headerMap.entrySet()) {
setHeader(e.getKey(), e.getValue());
}
}
if (privateHeaderMap != null) {
for (Map.Entry<String, String> e : privateHeaderMap.entrySet()) {
setPrivateHeader(e.getKey(), e.getValue());
}
}
// Request compressed response format
setHeader("Accept-Encoding", "gzip");
httpConn.setDoOutput(expectsInput);
}
/**
* Protected default constructor for testing.
*/
protected HttpGDataRequest() {
}
/**
* Obtains a connection to the GData service.
*/
protected HttpURLConnection getRequestConnection(URL requestUrl)
throws IOException {
if (!requestUrl.getProtocol().startsWith("http")) {
throw new UnsupportedOperationException("Unsupported scheme:"
+ requestUrl.getProtocol());
}
HttpURLConnection uc = (HttpURLConnection) requestUrl.openConnection();
// Should never cache GData requests/responses
uc.setUseCaches(false);
// Always follow redirects
uc.setInstanceFollowRedirects(true);
return uc;
}
public void setConnectTimeout(int timeout) {
if (timeout < 0) {
throw new IllegalArgumentException("Timeout cannot be negative");
}
connectTimeout = timeout;
}
public void setReadTimeout(int timeout) {
if (timeout < 0) {
throw new IllegalArgumentException("Timeout cannot be negative");
}
readTimeout = timeout;
}
public void setIfModifiedSince(DateTime conditionDate) {
if (conditionDate == null) {
return;
}
if (type == RequestType.QUERY) {
setHeader(GDataProtocol.Header.IF_MODIFIED_SINCE,
conditionDate.toStringRfc822());
} else {
throw new IllegalStateException(
"Date conditions not supported for this request type");
}
}
public void setEtag(String etag) {
if (etag == null) {
return;
}
switch (type) {
case QUERY:
if (etag != null) {
setHeader(GDataProtocol.Header.IF_NONE_MATCH, etag);
}
break;
case UPDATE:
case DELETE:
if (etag != null) {
setHeader(GDataProtocol.Header.IF_MATCH, etag);
}
break;
default:
throw new IllegalStateException(
"Etag conditions not supported for this request type");
}
}
public OutputStream getRequestStream() throws IOException {
if (!expectsInput) {
throw new IllegalStateException("Request doesn't accept input");
}
if (logger.isLoggable(Level.FINEST)){
return new LoggableOutputStream(logger, httpConn.getOutputStream());
}
return httpConn.getOutputStream();
}
public XmlWriter getRequestWriter() throws IOException {
OutputStream requestStream = getRequestStream();
Writer writer = new OutputStreamWriter(requestStream, "utf-8");
return new XmlWriter(writer);
}
public void setMethod(String method) throws ProtocolException {
httpConn.setRequestMethod(method);
if (logger.isLoggable(Level.FINE)) {
logger.fine(method + " " + httpConn.getURL().toExternalForm());
}
}
public void setHeader(String name, String value) {
httpConn.setRequestProperty(name, value);
logger.finer(name + ": " + value);
}
public void setPrivateHeader(String name, String value) {
httpConn.setRequestProperty(name, value);
logger.finer(name + ": <Not Logged>");
}
public void execute() throws IOException, ServiceException {
if (connectTimeout >= 0) {
httpConn.setConnectTimeout(connectTimeout);
}
if (readTimeout >= 0) {
httpConn.setReadTimeout(readTimeout);
}
// Set the http.strictPostRedirect property to prevent redirected
// POST/PUT/DELETE from being mapped to a GET. This
// system property was a hack to fix a jdk bug w/out changing back
// compat behavior. It's bogus that this is a system (and not a
// per-connection) property, so we just change it for the duration
// of the connection.
// See http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4023866
String httpStrictPostRedirect =
System.getProperty("http.strictPostRedirect");
try {
System.setProperty("http.strictPostRedirect", "true");
httpConn.connect();
if (logger.isLoggable(Level.FINE)) {
// Avoid calling URL.equals() unless an object equivalence test fails,
// because URL.equals() requires DNS resolution. This test will
// fail on the first check for any URLConnection implementation
// that derives from java.net.URLConnection. The 2nd check would
// work on an alternate impl that clones the URL.
if (httpConn.getURL() != requestUrl
&& !httpConn.getURL().toExternalForm().equals(
requestUrl.toExternalForm())) {
logger.fine("Redirected to:" + httpConn.getURL().toExternalForm());
}
// Log response information here, if enabled
logger.fine(httpConn.getResponseCode() + " "
+ httpConn.getResponseMessage());
if (logger.isLoggable(Level.FINER)) {
for (Map.Entry<String, List<String>> headerField : httpConn
.getHeaderFields().entrySet()) {
for (String value : headerField.getValue()) {
logger.finer(headerField.getKey() + ": " + value);
}
}
}
}
checkResponse(); // will flush any request data
} finally {
if (httpStrictPostRedirect == null) {
System.clearProperty("http.strictPostRedirect");
} else {
System.setProperty("http.strictPostRedirect", httpStrictPostRedirect);
}
}
executed = true;
}
/**
* Called after a request is executed to process the response and generate an
* appropriate exception (on failure).
*/
protected void checkResponse() throws IOException, ServiceException {
if (httpConn.getResponseCode() >= 300) {
handleErrorResponse();
}
}
/**
* Handles an error response received while executing a GData service request.
* Throws a {@link ServiceException} or one of its subclasses, depending on
* the failure conditions.
*
* @throws ServiceException exception describing the failure.
* @throws IOException error reading the error response from the GData
* service.
*/
protected void handleErrorResponse() throws ServiceException, IOException {
switch (httpConn.getResponseCode()) {
case HttpURLConnection.HTTP_NOT_FOUND:
throw new ResourceNotFoundException(httpConn);
case HttpURLConnection.HTTP_BAD_REQUEST:
throw new InvalidEntryException(httpConn);
case HttpURLConnection.HTTP_FORBIDDEN:
throw new ServiceForbiddenException(httpConn);
case HttpURLConnection.HTTP_UNAUTHORIZED:
throw new AuthenticationException(httpConn);
case HttpURLConnection.HTTP_NOT_MODIFIED:
throw new NotModifiedException(httpConn);
case HttpURLConnection.HTTP_PRECON_FAILED:
throw new PreconditionFailedException(httpConn);
case HttpURLConnection.HTTP_NOT_IMPLEMENTED:
throw new NotImplementedException(httpConn);
case HttpURLConnection.HTTP_CONFLICT:
throw new VersionConflictException(httpConn);
case HttpURLConnection.HTTP_ENTITY_TOO_LARGE:
throw new EntityTooLargeException(httpConn);
case HttpURLConnection.HTTP_NOT_ACCEPTABLE:
throw new NotAcceptableException(httpConn);
case HttpURLConnection.HTTP_GONE:
throw new NoLongerAvailableException(httpConn);
default:
throw new ServiceException(httpConn);
}
}
public ContentType getResponseContentType() {
if (!executed) {
throw new IllegalStateException(
"Must call execute() before attempting to read response");
}
String value = httpConn.getHeaderField("Content-Type");
if (value == null) {
return null;
}
return new ContentType(value);
}
public String getResponseHeader(String headerName) {
return httpConn.getHeaderField(headerName);
}
public DateTime getResponseDateHeader(String headerName) {
long dateValue = httpConn.getHeaderFieldDate(headerName, -1);
return (dateValue >= 0) ? new DateTime(dateValue) : null;
}
public InputStream getResponseStream() throws IOException {
if (!executed) {
throw new IllegalStateException(
"Must call execute() before attempting to read response");
}
if (!hasOutput) {
throw new IllegalStateException("Request doesn't have response data");
}
InputStream responseStream = httpConn.getInputStream();
if ("gzip".equalsIgnoreCase(httpConn.getContentEncoding())) {
responseStream = new GZIPInputStream(responseStream);
}
if (logger.isLoggable(Level.FINEST)){
return new LoggableInputStream(logger, responseStream);
}
return responseStream;
}
public ParseSource getParseSource() throws IOException {
return new ParseSource(getResponseStream());
}
/**
* Returns the URLConnection instance that represents the underlying
* connection to the GData service that will be used by this request.
*
* @return connection to GData service.
*/
public HttpURLConnection getConnection() {
return httpConn;
}
}