/*
* Copyright 2010 The Apache Software Foundation
*
* 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.hadoop.hbase.rest.client;
import java.io.IOException;
import java.util.Collections;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.commons.httpclient.Header;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.HttpVersion;
import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager;
import org.apache.commons.httpclient.URI;
import org.apache.commons.httpclient.methods.ByteArrayRequestEntity;
import org.apache.commons.httpclient.methods.DeleteMethod;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.HeadMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.PutMethod;
import org.apache.commons.httpclient.params.HttpClientParams;
import org.apache.commons.httpclient.params.HttpConnectionManagerParams;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* A wrapper around HttpClient which provides some useful function and
* semantics for interacting with the REST gateway.
*/
public class Client {
public static final Header[] EMPTY_HEADER_ARRAY = new Header[0];
private static final Log LOG = LogFactory.getLog(Client.class);
private HttpClient httpClient;
private Cluster cluster;
private Map<String, String> extraHeaders;
/**
* Default Constructor
*/
public Client() {
this(null);
}
/**
* Constructor
* @param cluster the cluster definition
*/
public Client(Cluster cluster) {
this.cluster = cluster;
MultiThreadedHttpConnectionManager manager =
new MultiThreadedHttpConnectionManager();
HttpConnectionManagerParams managerParams = manager.getParams();
managerParams.setConnectionTimeout(2000); // 2 s
managerParams.setDefaultMaxConnectionsPerHost(10);
managerParams.setMaxTotalConnections(100);
extraHeaders = new ConcurrentHashMap<String, String>();
this.httpClient = new HttpClient(manager);
HttpClientParams clientParams = httpClient.getParams();
clientParams.setVersion(HttpVersion.HTTP_1_1);
}
/**
* Shut down the client. Close any open persistent connections.
*/
public void shutdown() {
MultiThreadedHttpConnectionManager manager =
(MultiThreadedHttpConnectionManager) httpClient.getHttpConnectionManager();
manager.shutdown();
}
/**
* @return the wrapped HttpClient
*/
public HttpClient getHttpClient() {
return httpClient;
}
/**
* Add extra headers. These extra headers will be applied to all http
* methods before they are removed. If any header is not used any more,
* client needs to remove it explicitly.
*/
public void addExtraHeader(final String name, final String value) {
extraHeaders.put(name, value);
}
/**
* Get an extra header value.
*/
public String getExtraHeader(final String name) {
return extraHeaders.get(name);
}
/**
* Get all extra headers (read-only).
*/
public Map<String, String> getExtraHeaders() {
return Collections.unmodifiableMap(extraHeaders);
}
/**
* Remove an extra header.
*/
public void removeExtraHeader(final String name) {
extraHeaders.remove(name);
}
/**
* Execute a transaction method given only the path. Will select at random
* one of the members of the supplied cluster definition and iterate through
* the list until a transaction can be successfully completed. The
* definition of success here is a complete HTTP transaction, irrespective
* of result code.
* @param cluster the cluster definition
* @param method the transaction method
* @param headers HTTP header values to send
* @param path the properly urlencoded path
* @return the HTTP response code
* @throws IOException
*/
public int executePathOnly(Cluster cluster, HttpMethod method,
Header[] headers, String path) throws IOException {
IOException lastException;
if (cluster.nodes.size() < 1) {
throw new IOException("Cluster is empty");
}
int start = (int)Math.round((cluster.nodes.size() - 1) * Math.random());
int i = start;
do {
cluster.lastHost = cluster.nodes.get(i);
try {
StringBuilder sb = new StringBuilder();
sb.append("http://");
sb.append(cluster.lastHost);
sb.append(path);
URI uri = new URI(sb.toString(), true);
return executeURI(method, headers, uri.toString());
} catch (IOException e) {
lastException = e;
}
} while (++i != start && i < cluster.nodes.size());
throw lastException;
}
/**
* Execute a transaction method given a complete URI.
* @param method the transaction method
* @param headers HTTP header values to send
* @param uri a properly urlencoded URI
* @return the HTTP response code
* @throws IOException
*/
public int executeURI(HttpMethod method, Header[] headers, String uri)
throws IOException {
method.setURI(new URI(uri, true));
for (Map.Entry<String, String> e: extraHeaders.entrySet()) {
method.addRequestHeader(e.getKey(), e.getValue());
}
if (headers != null) {
for (Header header: headers) {
method.addRequestHeader(header);
}
}
long startTime = System.currentTimeMillis();
int code = httpClient.executeMethod(method);
long endTime = System.currentTimeMillis();
if (LOG.isDebugEnabled()) {
LOG.debug(method.getName() + " " + uri + " " + code + " " +
method.getStatusText() + " in " + (endTime - startTime) + " ms");
}
return code;
}
/**
* Execute a transaction method. Will call either <tt>executePathOnly</tt>
* or <tt>executeURI</tt> depending on whether a path only is supplied in
* 'path', or if a complete URI is passed instead, respectively.
* @param cluster the cluster definition
* @param method the HTTP method
* @param headers HTTP header values to send
* @param path the properly urlencoded path or URI
* @return the HTTP response code
* @throws IOException
*/
public int execute(Cluster cluster, HttpMethod method, Header[] headers,
String path) throws IOException {
if (path.startsWith("/")) {
return executePathOnly(cluster, method, headers, path);
}
return executeURI(method, headers, path);
}
/**
* @return the cluster definition
*/
public Cluster getCluster() {
return cluster;
}
/**
* @param cluster the cluster definition
*/
public void setCluster(Cluster cluster) {
this.cluster = cluster;
}
/**
* Send a HEAD request
* @param path the path or URI
* @return a Response object with response detail
* @throws IOException
*/
public Response head(String path) throws IOException {
return head(cluster, path, null);
}
/**
* Send a HEAD request
* @param cluster the cluster definition
* @param path the path or URI
* @param headers the HTTP headers to include in the request
* @return a Response object with response detail
* @throws IOException
*/
public Response head(Cluster cluster, String path, Header[] headers)
throws IOException {
HeadMethod method = new HeadMethod();
try {
int code = execute(cluster, method, null, path);
headers = method.getResponseHeaders();
return new Response(code, headers, null);
} finally {
method.releaseConnection();
}
}
/**
* Send a GET request
* @param path the path or URI
* @return a Response object with response detail
* @throws IOException
*/
public Response get(String path) throws IOException {
return get(cluster, path);
}
/**
* Send a GET request
* @param cluster the cluster definition
* @param path the path or URI
* @return a Response object with response detail
* @throws IOException
*/
public Response get(Cluster cluster, String path) throws IOException {
return get(cluster, path, EMPTY_HEADER_ARRAY);
}
/**
* Send a GET request
* @param path the path or URI
* @param accept Accept header value
* @return a Response object with response detail
* @throws IOException
*/
public Response get(String path, String accept) throws IOException {
return get(cluster, path, accept);
}
/**
* Send a GET request
* @param cluster the cluster definition
* @param path the path or URI
* @param accept Accept header value
* @return a Response object with response detail
* @throws IOException
*/
public Response get(Cluster cluster, String path, String accept)
throws IOException {
Header[] headers = new Header[1];
headers[0] = new Header("Accept", accept);
return get(cluster, path, headers);
}
/**
* Send a GET request
* @param path the path or URI
* @param headers the HTTP headers to include in the request,
* <tt>Accept</tt> must be supplied
* @return a Response object with response detail
* @throws IOException
*/
public Response get(String path, Header[] headers) throws IOException {
return get(cluster, path, headers);
}
/**
* Send a GET request
* @param c the cluster definition
* @param path the path or URI
* @param headers the HTTP headers to include in the request
* @return a Response object with response detail
* @throws IOException
*/
public Response get(Cluster c, String path, Header[] headers)
throws IOException {
GetMethod method = new GetMethod();
try {
int code = execute(c, method, headers, path);
headers = method.getResponseHeaders();
byte[] body = method.getResponseBody();
return new Response(code, headers, body);
} finally {
method.releaseConnection();
}
}
/**
* Send a PUT request
* @param path the path or URI
* @param contentType the content MIME type
* @param content the content bytes
* @return a Response object with response detail
* @throws IOException
*/
public Response put(String path, String contentType, byte[] content)
throws IOException {
return put(cluster, path, contentType, content);
}
/**
* Send a PUT request
* @param cluster the cluster definition
* @param path the path or URI
* @param contentType the content MIME type
* @param content the content bytes
* @return a Response object with response detail
* @throws IOException
*/
public Response put(Cluster cluster, String path, String contentType,
byte[] content) throws IOException {
Header[] headers = new Header[1];
headers[0] = new Header("Content-Type", contentType);
return put(cluster, path, headers, content);
}
/**
* Send a PUT request
* @param path the path or URI
* @param headers the HTTP headers to include, <tt>Content-Type</tt> must be
* supplied
* @param content the content bytes
* @return a Response object with response detail
* @throws IOException
*/
public Response put(String path, Header[] headers, byte[] content)
throws IOException {
return put(cluster, path, headers, content);
}
/**
* Send a PUT request
* @param cluster the cluster definition
* @param path the path or URI
* @param headers the HTTP headers to include, <tt>Content-Type</tt> must be
* supplied
* @param content the content bytes
* @return a Response object with response detail
* @throws IOException
*/
public Response put(Cluster cluster, String path, Header[] headers,
byte[] content) throws IOException {
PutMethod method = new PutMethod();
try {
method.setRequestEntity(new ByteArrayRequestEntity(content));
int code = execute(cluster, method, headers, path);
headers = method.getResponseHeaders();
content = method.getResponseBody();
return new Response(code, headers, content);
} finally {
method.releaseConnection();
}
}
/**
* Send a POST request
* @param path the path or URI
* @param contentType the content MIME type
* @param content the content bytes
* @return a Response object with response detail
* @throws IOException
*/
public Response post(String path, String contentType, byte[] content)
throws IOException {
return post(cluster, path, contentType, content);
}
/**
* Send a POST request
* @param cluster the cluster definition
* @param path the path or URI
* @param contentType the content MIME type
* @param content the content bytes
* @return a Response object with response detail
* @throws IOException
*/
public Response post(Cluster cluster, String path, String contentType,
byte[] content) throws IOException {
Header[] headers = new Header[1];
headers[0] = new Header("Content-Type", contentType);
return post(cluster, path, headers, content);
}
/**
* Send a POST request
* @param path the path or URI
* @param headers the HTTP headers to include, <tt>Content-Type</tt> must be
* supplied
* @param content the content bytes
* @return a Response object with response detail
* @throws IOException
*/
public Response post(String path, Header[] headers, byte[] content)
throws IOException {
return post(cluster, path, headers, content);
}
/**
* Send a POST request
* @param cluster the cluster definition
* @param path the path or URI
* @param headers the HTTP headers to include, <tt>Content-Type</tt> must be
* supplied
* @param content the content bytes
* @return a Response object with response detail
* @throws IOException
*/
public Response post(Cluster cluster, String path, Header[] headers,
byte[] content) throws IOException {
PostMethod method = new PostMethod();
try {
method.setRequestEntity(new ByteArrayRequestEntity(content));
int code = execute(cluster, method, headers, path);
headers = method.getResponseHeaders();
content = method.getResponseBody();
return new Response(code, headers, content);
} finally {
method.releaseConnection();
}
}
/**
* Send a DELETE request
* @param path the path or URI
* @return a Response object with response detail
* @throws IOException
*/
public Response delete(String path) throws IOException {
return delete(cluster, path);
}
/**
* Send a DELETE request
* @param cluster the cluster definition
* @param path the path or URI
* @return a Response object with response detail
* @throws IOException
*/
public Response delete(Cluster cluster, String path) throws IOException {
DeleteMethod method = new DeleteMethod();
try {
int code = execute(cluster, method, null, path);
Header[] headers = method.getResponseHeaders();
byte[] content = method.getResponseBody();
return new Response(code, headers, content);
} finally {
method.releaseConnection();
}
}
}