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  • hbase java API跟新数据,创建表

    package hbaseCURD;
    
    import java.io.IOException;
    
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.client.Get;
    import org.apache.hadoop.hbase.client.HTable;
    import org.apache.hadoop.hbase.client.Put;
    import org.apache.hadoop.hbase.client.Result;
    import org.apache.hadoop.hbase.util.Bytes;
    
    public class test {
    
    public static void main(String[] args) throws IOException {
    
        TableManager tm = new TableManager();
        tm.getConf();
    //  tm.createTable("testtable","cf1","cf2");
        HTable mytable=tm.getTableObj("testtable");
    //  Put put = new Put(Bytes.toBytes("row1"));
    //  put.add(Bytes.toBytes("cf1"), Bytes.toBytes("c1"), Bytes.toBytes("cf1ddfddvalue"));
    //  put.add(Bytes.toBytes("cf2"), Bytes.toBytes("c2"), Bytes.toBytes("cf2v3333alue"));
    //  mytable.put(put);
    //查询
        Get get = new Get(Bytes.toBytes("row1"));  
        Result result = mytable.get(get);  
        System.out.println("get result:" + Bytes.toString(result.getValue(Bytes.toBytes("cf1"), Bytes.toBytes("c1"))));  
        //Result[] result = table.get(List<Get>);//查询指定Rowkey的多条记录  
    
    }
    
    
    
    }
    
    package hbaseCURD;
    
    import java.io.IOException;
    
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.HColumnDescriptor;
    import org.apache.hadoop.hbase.HTableDescriptor;
    import org.apache.hadoop.hbase.MasterNotRunningException;
    import org.apache.hadoop.hbase.ZooKeeperConnectionException;
    import org.apache.hadoop.hbase.client.HBaseAdmin;
    import org.apache.hadoop.hbase.client.HTable;
    import org.apache.hadoop.hbase.util.Bytes;
    
    public class TableManager {
        private static Configuration conf;
    
        // 设置集群的配置信息
        public void getConf() {
            conf = HBaseConfiguration.create();
            conf.set("hbase.zookeeper.quorum", "master,slave1,slave2");
            conf.set("hbase.master", "master:60000");
        }
    
        // 获取表对象
        public HTable getTableObj(String tablename) {
            HTable mytable = null;
            try {
                mytable = new HTable(conf, tablename);
            } catch (IOException e) {
                e.printStackTrace();
            }
            return mytable;
        }
    
        //
        public void createTable(String tableName, String... args) throws MasterNotRunningException, ZooKeeperConnectionException {
            // args数组保存的是列族
            HBaseAdmin admin = new HBaseAdmin(conf);
            // 创建表
            HTableDescriptor htd = new HTableDescriptor(tableName);
            for (String st : args) {
                htd.addFamily(new HColumnDescriptor(st));
            }
            try {
                admin.createTable(htd);
            } catch (IOException e) {
                e.printStackTrace();
            }
    
        }
    
        public void deleteTable(String tableName) {
            try {
                HBaseAdmin admin = new HBaseAdmin(conf);
                // 创建表
                HTableDescriptor htd = new HTableDescriptor(tableName);
                admin.disableTable(Bytes.toBytes(tableName));
                admin.deleteTable(Bytes.toBytes(tableName));
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }  
        }
        public void modifyTable(String tableName,String newcoloumf) {
            try {
                HBaseAdmin admin = new HBaseAdmin(conf);
                // 创建表
                HTableDescriptor htd = new HTableDescriptor(tableName);
                admin.disableTable(Bytes.toBytes(tableName));
                admin.modifyColumn(tableName, new HColumnDescriptor("cf1"));    
                admin.enableTable(tableName);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }  
        }
    
    }
    

    Hbase的访问方式
    1、Native Java API:最常规和高效的访问方式;
    2、HBase Shell:HBase的命令行工具,最简单的接口,适合HBase管理使用;
    3、Thrift Gateway:利用Thrift序列化技术,支持C++,PHP,Python等多种语言,适合其他异构系统在线访问HBase表数据;
    4、REST Gateway:支持REST 风格的Http API访问HBase, 解除了语言限制;
    5、MapReduce:直接使用MapReduce作业处理Hbase数据;
    6、使用Pig/hive处理Hbase数据。
    常用Java API的用法:

    1、加载配置

    [java] view plaincopy在CODE上查看代码片派生到我的代码片
    Configuration config = HBaseConfiguration.create();
    //可以自定义配置,也可以从自定义配置文件中读取
    /*config.set(“hbase.zookeeper.property.clientPort”, “4181”);
    config.set(“hbase.zookeeper.quorum”, “hadoop.datanode5.com,hadoop.datanode2.com,hadoop.datanode3.com”);
    config.set(“hbase.master”, “hadoop.datanode3.com:600000”);*/
    2、表的创建、表信息修改、表删除

    [java] view plaincopy在CODE上查看代码片派生到我的代码片
    HBaseAdmin admin = new HBaseAdmin(config);
    //创建表
    HTableDescriptor htd = new HTableDescriptor(tableName);
    htd.addFamily(new HColumnDescriptor(“cf1”));
    htd.addFamily(new HColumnDescriptor(“cf2”));
    admin.createTable(htd);
    //修改表信息
    admin.disableTable(tableName);
    // modifying existing ColumnFamily
    admin.modifyColumn(tableName, new HColumnDescriptor(“cf1”));
    admin.enableTable(tableName);
    //删除表
    admin.disableTable(Bytes.toBytes(tableName));
    admin.deleteTable(Bytes.toBytes(tableName));
    3、添加记录
    [java] view plaincopy在CODE上查看代码片派生到我的代码片
    /** 在多次使用时,建议用HTablePool
    HTable table = new HTable(config, tableName);
    =>
    HTablePool pool = new HTablePool(config, 1000);
    HTableInterface table = pool.getTable(tableName);*/
    HTable table = new HTable(config, tableName);

    /**
    * 在插入操作时,默认不适用任何缓存
    * 可自定义使用缓存,以及缓存大小
    * 每个任务最后需要手工调用 flushCommits();
    */
    /*table.setAutoFlush(false);
    table.setWriteBufferSize(1024);*/

    Put put1 = new Put(Bytes.toBytes(rowKey));
    if (ts == 0) {
    put1.add(Bytes.toBytes(family), Bytes.toBytes(qualifier), Bytes.toBytes(value));
    } else {
    //自定义版本时,从自定义的版本号,类型为long
    put1.add(Bytes.toBytes(family), Bytes.toBytes(qualifier), ts,Bytes.toBytes(value));
    }
    table.put(put1);
    //table.flushCommits();
    4、查询,根据Rowkey查询
    [java] view plaincopy在CODE上查看代码片派生到我的代码片
    Get get1 = new Get(Bytes.toBytes(rowKey));
    Result result = table.get(get1);
    System.out.println(“get result:” + Bytes.toString(result.getValue(Bytes.toBytes(family), Bytes.toBytes(qualifier))));
    Result[] result = table.get(List);//查询指定Rowkey的多条记录
    5、查询,指定条件和rowkey区间查询
    [java] view plaincopy在CODE上查看代码片派生到我的代码片
    Scan scan = new Scan();
    //默认缓存大小为1,设置成一个合理的值,可以减少scan过程中next()的时间开销,代价是客户端的内存
    scan.setCaching(500);
    scan.setCacheBlocks(false);

    //根据startRowKey、endRowKey查询
    //Scan scan = new Scan(Bytes.toBytes(“startRowKey”), Bytes.toBytes(“endRowKey”));

    //rowKey之外的过滤条件,在List中可以add;
    /**List filters = new ArrayList();
    Filter filter = new SingleColumnValueFilter(“familyName”.getBytes(),
    “qualifierName”.getBytes(),
    CompareOp.EQUAL,
    Bytes.toBytes(“value”));
    filters.add(filter);
    scan.setFilter(new FilterList(filters));*/

    ResultScanner scanner = table.getScanner(scan);

    System.out.println(“scan result list:”);

    for (Result result : scanner) {
    System.out.println(Bytes.toString(result.getRow()));
    System.out.println(Bytes.toString(result.getValue(Bytes.toBytes(“data”), Bytes.toBytes(“data1”))));
    System.out.println(Bytes.toString(result.getValue(Bytes.toBytes(“data”), Bytes.toBytes(“data2”))));
    }
    scanner.close();
    参考:
    1、http://www.taobaotest.com/blogs/1605

    2、http://abloz.com/hbase/book.html#data_model_operations(官网示例)

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  • 原文地址:https://www.cnblogs.com/mrcharles/p/11879918.html
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