org.apache.hadoop.fs.http.client.HttpFSUtils.java Source code

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Here is the source code for org.apache.hadoop.fs.http.client.HttpFSUtils.java

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/**
 * 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.commons.io.Charsets;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.fs.Path;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;

import java.io.IOException;
import java.io.InputStreamReader;
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());
    }

    /**
     * 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(), Charsets.UTF_8));
        } catch (ParseException ex) {
            throw new IOException("JSON parser error, " + ex.getMessage(), ex);
        }
    }
}