com.cloudera.nav.sdk.client.writer.MetadataWriterFactory.java Source code

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Here is the source code for com.cloudera.nav.sdk.client.writer.MetadataWriterFactory.java

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/*
 * Copyright (c) 2015 Cloudera, 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.cloudera.nav.sdk.client.writer;

import com.cloudera.nav.sdk.client.ClientConfig;
import com.cloudera.nav.sdk.client.SSLUtils;
import com.google.common.base.Throwables;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URI;
import java.net.URL;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;

import org.apache.commons.net.util.Base64;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;

/**
 * A factory that returns the appropriate MetadataWriter given a set of
 * configurations
 */
public class MetadataWriterFactory {

    public static final String HDFS = "hdfs";
    public static final String LOCAL = "file";
    public static final String HTTP = "http";

    private final ClientConfig config;
    private final boolean isSSL;
    private final SSLContext sslContext;
    private final HostnameVerifier hostnameVerifier;

    public MetadataWriterFactory(ClientConfig config) {
        this.config = config;
        this.isSSL = SSLUtils.isSSL(config.getMetadataParentUriString());
        this.sslContext = isSSL ? SSLUtils.getSSLContext(config) : null;
        this.hostnameVerifier = isSSL ? SSLUtils.getHostnameVerifier(config) : null;
    }

    /**
     * Create a new metadata writer
     */
    public MetadataWriter newWriter() {
        String scheme = getScheme();
        if (scheme.equals(HDFS)) {
            throw new UnsupportedOperationException();
        } else if (scheme.equals(LOCAL)) {
            throw new UnsupportedOperationException();
        } else {
            try {
                HttpURLConnection conn = createHttpStream();
                OutputStream stream = new BufferedOutputStream(conn.getOutputStream());
                return new JsonMetadataWriter(config, stream, conn);
            } catch (IOException e) {
                throw Throwables.propagate(e);
            }
        }
    }

    /**
     * Return lower cased metadata parent uri scheme. If null then empty
     * string is returned (for easier string comparisons).
     */
    private String getScheme() {
        URI uri = config.getMetadataParentUri();
        String scheme = uri.getScheme();
        return scheme == null ? "" : scheme.toLowerCase();
    }

    private HttpURLConnection createHttpStream() throws IOException {
        URL url = new URL(config.getMetadataParentUri().toASCIIString());
        HttpURLConnection conn = openConnection(url);
        conn.setRequestMethod("POST");
        String userpass = config.getUsername() + ":" + config.getPassword();
        String basicAuth = "Basic " + new String(Base64.encodeBase64(userpass.getBytes()));
        conn.addRequestProperty("Authorization", basicAuth);
        conn.addRequestProperty("Content-Type", "application/json");
        conn.setDoOutput(true);
        return conn;
    }

    private HttpURLConnection openConnection(URL url) throws IOException {
        if (isSSL) {
            HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
            conn.setHostnameVerifier(hostnameVerifier);
            conn.setSSLSocketFactory(sslContext.getSocketFactory());
            return conn;
        } else {
            return (HttpURLConnection) url.openConnection();
        }
    }

    private OutputStream createLocalFileStream() {
        String fileName = getFilePath(config.getMetadataParentUri().getPath());
        File file = new File(fileName);
        try {
            file.createNewFile();
        } catch (IOException e) {
            throw Throwables.propagate(e);
        }
        try {
            return new FileOutputStream(file);
        } catch (FileNotFoundException e) {
            throw Throwables.propagate(e);
        }
    }

    private OutputStream createHdfsStream() {
        try {
            FileSystem fs = FileSystem.get(config.getHadoopConfigurations());
            Path path = new Path(getFilePath(config.getMetadataParentUriString()));
            if (fs.exists(path)) {
                return fs.append(path);
            }
            // TODO block sizes, replication counts etc
            return fs.create(path);
        } catch (IOException e) {
            throw Throwables.propagate(e);
        }
    }

    private String getFilePath(String path) {
        // TODO file rotation
        if (!path.endsWith("/")) {
            path += "/";
        }
        return path + ".metadata";
    }

}