/**
* 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.fs.http.client;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.fs.Path;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.lang.reflect.Constructor;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URL;
import java.net.URLEncoder;
import java.text.MessageFormat;
import java.util.List;
import java.util.Map;
/**
* Utility methods used by HttpFS classes.
*/
@InterfaceAudience.Private
public class HttpFSUtils {
public static final String SERVICE_NAME = "/webhdfs";
public static final String SERVICE_VERSION = "/v1";
private static final String SERVICE_PATH = SERVICE_NAME + SERVICE_VERSION;
/**
* Convenience method that creates an HTTP <code>URL</code> for the
* HttpFSServer file system operations.
* <p/>
*
* @param path the file path.
* @param params the query string parameters.
*
* @return a <code>URL</code> for the HttpFSServer server,
*
* @throws IOException thrown if an IO error occurs.
*/
static URL createURL(Path path, Map<String, String> params)
throws IOException {
return createURL(path, params, null);
}
/**
* Convenience method that creates an HTTP <code>URL</code> for the
* HttpFSServer file system operations.
* <p/>
*
* @param path the file path.
* @param params the query string parameters.
* @param multiValuedParams multi valued parameters of the query string
*
* @return URL a <code>URL</code> for the HttpFSServer server,
*
* @throws IOException thrown if an IO error occurs.
*/
static URL createURL(Path path, Map<String, String> params, Map<String,
List<String>> multiValuedParams) throws IOException {
URI uri = path.toUri();
String realScheme;
if (uri.getScheme().equalsIgnoreCase(HttpFSFileSystem.SCHEME)) {
realScheme = "http";
} else if (uri.getScheme().equalsIgnoreCase(HttpsFSFileSystem.SCHEME)) {
realScheme = "https";
} else {
throw new IllegalArgumentException(MessageFormat.format(
"Invalid scheme [{0}] it should be '" + HttpFSFileSystem.SCHEME + "' " +
"or '" + HttpsFSFileSystem.SCHEME + "'", uri));
}
StringBuilder sb = new StringBuilder();
sb.append(realScheme).append("://").append(uri.getAuthority()).
append(SERVICE_PATH).append(uri.getPath());
String separator = "?";
for (Map.Entry<String, String> entry : params.entrySet()) {
sb.append(separator).append(entry.getKey()).append("=").
append(URLEncoder.encode(entry.getValue(), "UTF8"));
separator = "&";
}
if (multiValuedParams != null) {
for (Map.Entry<String, List<String>> multiValuedEntry :
multiValuedParams.entrySet()) {
String name = URLEncoder.encode(multiValuedEntry.getKey(), "UTF8");
List<String> values = multiValuedEntry.getValue();
for (String value : values) {
sb.append(separator).append(name).append("=").
append(URLEncoder.encode(value, "UTF8"));
separator = "&";
}
}
}
return new URL(sb.toString());
}
/**
* Validates the status of an <code>HttpURLConnection</code> against an
* expected HTTP status code. If the current status code is not the expected
* one it throws an exception with a detail message using Server side error
* messages if available.
*
* @param conn the <code>HttpURLConnection</code>.
* @param expected the expected HTTP status code.
*
* @throws IOException thrown if the current status code does not match the
* expected one.
*/
@SuppressWarnings({"unchecked"})
static void validateResponse(HttpURLConnection conn, int expected)
throws IOException {
int status = conn.getResponseCode();
if (status != expected) {
try {
JSONObject json = (JSONObject) HttpFSUtils.jsonParse(conn);
json = (JSONObject) json.get(HttpFSFileSystem.ERROR_JSON);
String message = (String) json.get(HttpFSFileSystem.ERROR_MESSAGE_JSON);
String exception = (String)
json.get(HttpFSFileSystem.ERROR_EXCEPTION_JSON);
String className = (String)
json.get(HttpFSFileSystem.ERROR_CLASSNAME_JSON);
try {
ClassLoader cl = HttpFSFileSystem.class.getClassLoader();
Class klass = cl.loadClass(className);
Constructor constr = klass.getConstructor(String.class);
throw (IOException) constr.newInstance(message);
} catch (IOException ex) {
throw ex;
} catch (Exception ex) {
throw new IOException(MessageFormat.format("{0} - {1}", exception,
message));
}
} catch (IOException ex) {
if (ex.getCause() instanceof IOException) {
throw (IOException) ex.getCause();
}
throw new IOException(
MessageFormat.format("HTTP status [{0}], {1}",
status, conn.getResponseMessage()));
}
}
}
/**
* Convenience method that JSON Parses the <code>InputStream</code> of a
* <code>HttpURLConnection</code>.
*
* @param conn the <code>HttpURLConnection</code>.
*
* @return the parsed JSON object.
*
* @throws IOException thrown if the <code>InputStream</code> could not be
* JSON parsed.
*/
static Object jsonParse(HttpURLConnection conn) throws IOException {
try {
JSONParser parser = new JSONParser();
return parser.parse(new InputStreamReader(conn.getInputStream()));
} catch (ParseException ex) {
throw new IOException("JSON parser error, " + ex.getMessage(), ex);
}
}
}