HBase总结（十二）Java API 与HBase交互实例

HBase提供了Java Api的访问接口，掌握这个就跟Java应用使用RDBMS时需要JDBC一样重要

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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.KeyValue;  

import org.apache.hadoop.hbase.client.Delete;  

import org.apache.hadoop.hbase.client.Get;  

import org.apache.hadoop.hbase.client.HBaseAdmin;  

import org.apache.hadoop.hbase.client.HTable;  

import org.apache.hadoop.hbase.client.HTablePool;  

import org.apache.hadoop.hbase.client.Put;  

import org.apache.hadoop.hbase.client.Result;  

import org.apache.hadoop.hbase.client.ResultScanner;  

import org.apache.hadoop.hbase.client.Scan;  

import org.apache.hadoop.hbase.util.Bytes;  

  

public class Hbase {  

    // 声明静态配置  

    static Configuration conf = null;  

    static {  

        conf = HBaseConfiguration.create();  

        conf.set("hbase.zookeeper.quorum", "localhost");  

    }  

  

    /*  

     * 创建表  

     *   

     * @tableName 表名  

     *   

     * @family 列族列表  

     */  

    public static void creatTable(String tableName, String[] family)  

            throws Exception {  

        HBaseAdmin admin = new HBaseAdmin(conf);  

        HTableDescriptor desc = new HTableDescriptor(tableName);  

        for (int i = 0; i < family.length; i++) {  

            desc.addFamily(new HColumnDescriptor(family[i]));  

        }  

        if (admin.tableExists(tableName)) {  

            System.out.println("table Exists!");  

            System.exit(0);  

        } else {  

            admin.createTable(desc);  

            System.out.println("create table Success!");  

        }  

    }  

  

    /*  

     * 为表添加数据（适合知道有多少列族的固定表）  

     *   

     * @rowKey rowKey  

     *   

     * @tableName 表名  

     *   

     * @column1 第一个列族列表  

     *   

     * @value1 第一个列的值的列表  

     *   

     * @column2 第二个列族列表  

     *   

     * @value2 第二个列的值的列表  

     */  

    public static void addData(String rowKey, String tableName,  

            String[] column1, String[] value1, String[] column2, String[] value2)  

            throws IOException {  

        Put put = new Put(Bytes.toBytes(rowKey));// 设置rowkey  

        HTable table = new HTable(conf, Bytes.toBytes(tableName));// HTabel负责跟记录相关的操作如增删改查等//  

                                                                    // 获取表  

        HColumnDescriptor[] columnFamilies = table.getTableDescriptor() // 获取所有的列族  

                .getColumnFamilies();  

  

        for (int i = 0; i < columnFamilies.length; i++) {  

            String familyName = columnFamilies[i].getNameAsString(); // 获取列族名  

            if (familyName.equals("article")) { // article列族put数据  

                for (int j = 0; j < column1.length; j++) {  

                    put.add(Bytes.toBytes(familyName),  

                            Bytes.toBytes(column1[j]), Bytes.toBytes(value1[j]));  

                }  

            }  

            if (familyName.equals("author")) { // author列族put数据  

                for (int j = 0; j < column2.length; j++) {  

                    put.add(Bytes.toBytes(familyName),  

                            Bytes.toBytes(column2[j]), Bytes.toBytes(value2[j]));  

                }  

            }  

        }  

        table.put(put);  

        System.out.println("add data Success!");  

    }  

  

    /*  

     * 根据rwokey查询  

     *   

     * @rowKey rowKey  

     *   

     * @tableName 表名  

     */  

    public static Result getResult(String tableName, String rowKey)  

            throws IOException {  

        Get get = new Get(Bytes.toBytes(rowKey));  

        HTable table = new HTable(conf, Bytes.toBytes(tableName));// 获取表  

        Result result = table.get(get);  

        for (KeyValue kv : result.list()) {  

            System.out.println("family:" + Bytes.toString(kv.getFamily()));  

            System.out  

                    .println("qualifier:" + Bytes.toString(kv.getQualifier()));  

            System.out.println("value:" + Bytes.toString(kv.getValue()));  

            System.out.println("Timestamp:" + kv.getTimestamp());  

            System.out.println("-------------------------------------------");  

        }  

        return result;  

    }  

  

    /*  

     * 遍历查询hbase表  

     *   

     * @tableName 表名  

     */  

    public static void getResultScann(String tableName) throws IOException {  

        Scan scan = new Scan();  

        ResultScanner rs = null;  

        HTable table = new HTable(conf, Bytes.toBytes(tableName));  

        try {  

            rs = table.getScanner(scan);  

            for (Result r : rs) {  

                for (KeyValue kv : r.list()) {  

                    System.out.println("row:" + Bytes.toString(kv.getRow()));  

                    System.out.println("family:"  

                            + Bytes.toString(kv.getFamily()));  

                    System.out.println("qualifier:"  

                            + Bytes.toString(kv.getQualifier()));  

                    System.out  

                            .println("value:" + Bytes.toString(kv.getValue()));  

                    System.out.println("timestamp:" + kv.getTimestamp());  

                    System.out  

                            .println("-------------------------------------------");  

                }  

            }  

        } finally {  

            rs.close();  

        }  

    }  

  

    /*  

     * 遍历查询hbase表  

     *   

     * @tableName 表名  

     */  

    public static void getResultScann(String tableName, String start_rowkey,  

            String stop_rowkey) throws IOException {  

        Scan scan = new Scan();  

        scan.setStartRow(Bytes.toBytes(start_rowkey));  

        scan.setStopRow(Bytes.toBytes(stop_rowkey));  

        ResultScanner rs = null;  

        HTable table = new HTable(conf, Bytes.toBytes(tableName));  

        try {  

            rs = table.getScanner(scan);  

            for (Result r : rs) {  

                for (KeyValue kv : r.list()) {  

                    System.out.println("row:" + Bytes.toString(kv.getRow()));  

                    System.out.println("family:"  

                            + Bytes.toString(kv.getFamily()));  

                    System.out.println("qualifier:"  

                            + Bytes.toString(kv.getQualifier()));  

                    System.out  

                            .println("value:" + Bytes.toString(kv.getValue()));  

                    System.out.println("timestamp:" + kv.getTimestamp());  

                    System.out  

                            .println("-------------------------------------------");  

                }  

            }  

        } finally {  

            rs.close();  

        }  

    }  

  

    /*  

     * 查询表中的某一列  

     *   

     * @tableName 表名  

     *   

     * @rowKey rowKey  

     */  

    public static void getResultByColumn(String tableName, String rowKey,  

            String familyName, String columnName) throws IOException {  

        HTable table = new HTable(conf, Bytes.toBytes(tableName));  

        Get get = new Get(Bytes.toBytes(rowKey));  

        get.addColumn(Bytes.toBytes(familyName), Bytes.toBytes(columnName)); // 获取指定列族和列修饰符对应的列  

        Result result = table.get(get);  

        for (KeyValue kv : result.list()) {  

            System.out.println("family:" + Bytes.toString(kv.getFamily()));  

            System.out  

                    .println("qualifier:" + Bytes.toString(kv.getQualifier()));  

            System.out.println("value:" + Bytes.toString(kv.getValue()));  

            System.out.println("Timestamp:" + kv.getTimestamp());  

            System.out.println("-------------------------------------------");  

        }  

    }  

  

    /*  

     * 更新表中的某一列  

     *   

     * @tableName 表名  

     *   

     * @rowKey rowKey  

     *   

     * @familyName 列族名  

     *   

     * @columnName 列名  

     *   

     * @value 更新后的值  

     */  

    public static void updateTable(String tableName, String rowKey,  

            String familyName, String columnName, String value)  

            throws IOException {  

        HTable table = new HTable(conf, Bytes.toBytes(tableName));  

        Put put = new Put(Bytes.toBytes(rowKey));  

        put.add(Bytes.toBytes(familyName), Bytes.toBytes(columnName),  

                Bytes.toBytes(value));  

        table.put(put);  

        System.out.println("update table Success!");  

    }  

  

    /*  

     * 查询某列数据的多个版本  

     *   

     * @tableName 表名  

     *   

     * @rowKey rowKey  

     *   

     * @familyName 列族名  

     *   

     * @columnName 列名  

     */  

    public static void getResultByVersion(String tableName, String rowKey,  

            String familyName, String columnName) throws IOException {  

        HTable table = new HTable(conf, Bytes.toBytes(tableName));  

        Get get = new Get(Bytes.toBytes(rowKey));  

        get.addColumn(Bytes.toBytes(familyName), Bytes.toBytes(columnName));  

        get.setMaxVersions(5);  

        Result result = table.get(get);  

        for (KeyValue kv : result.list()) {  

            System.out.println("family:" + Bytes.toString(kv.getFamily()));  

            System.out  

                    .println("qualifier:" + Bytes.toString(kv.getQualifier()));  

            System.out.println("value:" + Bytes.toString(kv.getValue()));  

            System.out.println("Timestamp:" + kv.getTimestamp());  

            System.out.println("-------------------------------------------");  

        }  

        /*  

         * List<?> results = table.get(get).list(); Iterator<?> it =  

         * results.iterator(); while (it.hasNext()) {  

         * System.out.println(it.next().toString()); }  

         */  

    }  

  

    /*  

     * 删除指定的列  

     *   

     * @tableName 表名  

     *   

     * @rowKey rowKey  

     *   

     * @familyName 列族名  

     *   

     * @columnName 列名  

     */  

    public static void deleteColumn(String tableName, String rowKey,  

            String falilyName, String columnName) throws IOException {  

        HTable table = new HTable(conf, Bytes.toBytes(tableName));  

        Delete deleteColumn = new Delete(Bytes.toBytes(rowKey));  

        deleteColumn.deleteColumns(Bytes.toBytes(falilyName),  

                Bytes.toBytes(columnName));  

        table.delete(deleteColumn);  

        System.out.println(falilyName + ":" + columnName + "is deleted!");  

    }  

  

    /*  

     * 删除指定的列  

     *   

     * @tableName 表名  

     *   

     * @rowKey rowKey  

     */  

    public static void deleteAllColumn(String tableName, String rowKey)  

            throws IOException {  

        HTable table = new HTable(conf, Bytes.toBytes(tableName));  

        Delete deleteAll = new Delete(Bytes.toBytes(rowKey));  

        table.delete(deleteAll);  

        System.out.println("all columns are deleted!");  

    }  

  

    /*  

     * 删除表  

     *   

     * @tableName 表名  

     */  

    public static void deleteTable(String tableName) throws IOException {  

        HBaseAdmin admin = new HBaseAdmin(conf);  

        admin.disableTable(tableName);  

        admin.deleteTable(tableName);  

        System.out.println(tableName + "is deleted!");  

    }  

  

    public static void main(String[] args) throws Exception {  

  

        // 创建表  

        String tableName = "blog2";  

        String[] family = { "article", "author" };  

        // creatTable(tableName, family);  

  

        // 为表添加数据  

  

        String[] column1 = { "title", "content", "tag" };  

        String[] value1 = {  

                "Head First HBase",  

                "HBase is the Hadoop database. Use it when you need random, realtime read/write access to your Big Data.",  

                "Hadoop,HBase,NoSQL" };  

        String[] column2 = { "name", "nickname" };  

        String[] value2 = { "nicholas", "lee" };  

        addData("rowkey1", "blog2", column1, value1, column2, value2);  

        addData("rowkey2", "blog2", column1, value1, column2, value2);  

        addData("rowkey3", "blog2", column1, value1, column2, value2);  

  

        // 遍历查询  

        getResultScann("blog2", "rowkey4", "rowkey5");  

        // 根据row key范围遍历查询  

        getResultScann("blog2", "rowkey4", "rowkey5");  

  

        // 查询  

        getResult("blog2", "rowkey1");  

  

        // 查询某一列的值  

        getResultByColumn("blog2", "rowkey1", "author", "name");  

  

        // 更新列  

        updateTable("blog2", "rowkey1", "author", "name", "bin");  

  

        // 查询某一列的值  

        getResultByColumn("blog2", "rowkey1", "author", "name");  

  

        // 查询某列的多版本  

        getResultByVersion("blog2", "rowkey1", "author", "name");  

  

        // 删除一列  

        deleteColumn("blog2", "rowkey1", "author", "nickname");  

  

        // 删除所有列  

        deleteAllColumn("blog2", "rowkey1");  

  

        // 删除表  

        deleteTable("blog2");  

  

    }  

}