• HBase常用的数据库API操作


      需要引入Hadoop和Hbase的jar包,我这里HBase用的是hbase-0.90.5版本,所以我这里引入的HBase的jar包是hbase-0.90.5.jar和zookeeper-3.3.2.jar。

      一些常用的API操作:

    package cn.luxh.app.util;
    
    import java.io.IOException;
    import java.util.Arrays;
    
    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.Get;
    import org.apache.hadoop.hbase.client.HBaseAdmin;
    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.client.ResultScanner;
    import org.apache.hadoop.hbase.client.Scan;
    import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
    import org.apache.hadoop.hbase.filter.Filter;
    import org.apache.hadoop.hbase.filter.FilterList;
    import org.apache.hadoop.hbase.filter.FilterList.Operator;
    import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;
    import org.apache.hadoop.hbase.util.Bytes;
    
    public class HBaseUtil {
        
        /**
         * 初始化HBase的配置文件
         * @return
         */
        public static Configuration getConfiguration(){
            Configuration conf = HBaseConfiguration.create();
            //和hbase-site.xml中配置的一致
            conf.set("hbase.zooker.quorum", "h1,h2,h3");
            return conf;
        }
        
        /**
         * 实例化HBaseAdmin,HBaseAdmin用于对表的元素据进行操作
         * @return
         * @throws MasterNotRunningException
         * @throws ZooKeeperConnectionException
         */
        public static HBaseAdmin getHBaseAdmin() throws MasterNotRunningException, ZooKeeperConnectionException{
            return new HBaseAdmin(getConfiguration());
        }
        
        /**
         * 创建表
         * @param tableName            表名
         * @param columnFamilies    列族
         * @throws IOException
         */
        public static void createTable(String tableName,String...columnFamilies) throws IOException {
            HTableDescriptor htd = new HTableDescriptor(tableName.getBytes());//
            for(String fc : columnFamilies) {
                htd.addFamily(new HColumnDescriptor(fc));
            }
            getHBaseAdmin().createTable(htd);
        }
        
        /**
         * 获取HTableDescriptor
         * @param tableName
         * @return
         * @throws IOException
         */
        public static HTableDescriptor getHTableDescriptor(byte[] tableName) throws IOException{
            return getHBaseAdmin().getTableDescriptor(tableName); 
        }
        
        /**
         * 获取表
         * @param tableName 表名
         * @return
         * @throws IOException
         */
        public static HTable getHTable(String tableName) throws IOException{
            return new HTable(getConfiguration(),tableName);
        }
        
        /**
         * 获取Put,Put是插入一行数据的封装格式
         * @param tableName
         * @param row
         * @param columnFamily
         * @param qualifier
         * @param value
         * @return
         * @throws IOException
         */
        public static Put getPut(String row,String columnFamily,String qualifier,String value) throws IOException{
            Put put = new Put(row.getBytes());
            if(qualifier==null||"".equals(qualifier)) {
                put.add(columnFamily.getBytes(), null, value.getBytes());
            }else {
                put.add(columnFamily.getBytes(), qualifier.getBytes(), value.getBytes());
            }
            return put;
        }
        
        /**
         * 查询某一行的数据
         * @param tableName    表名
         * @param row        行键
         * @return
         * @throws IOException
         */
        public static Result getResult(String tableName,String row) throws IOException {
            Get get = new Get(row.getBytes());
            HTable htable  = getHTable(tableName);
            Result result = htable.get(get);
            htable.close();
            return result;
            
        }
        
        /**
         * 条件查询
         * @param tableName        表名
         * @param columnFamily    列族
         * @param queryCondition    查询条件值
         * @param begin                查询的起始行
         * @param end                查询的终止行
         * @return
         * @throws IOException
         */
        public static ResultScanner getResultScanner(String tableName,String columnFamily,String queryCondition,String begin,String end) throws IOException{
            
            Scan scan = new Scan();
            //设置起始行
            scan.setStartRow(Bytes.toBytes(begin));
            //设置终止行
            scan.setStopRow(Bytes.toBytes(end));
            
            //指定要查询的列族
            scan.addColumn(Bytes.toBytes(columnFamily),null);
            //查询列族中值等于queryCondition的记录
            Filter filter1 = new SingleColumnValueFilter(Bytes.toBytes(columnFamily),null,CompareOp.EQUAL,Bytes.toBytes(queryCondition));
            //Filter filter2 = new SingleColumnValueFilter(Bytes.toBytes(columnFamily),null,CompareOp.EQUAL,Bytes.toBytes("chuliuxiang"));
            
            FilterList filterList = new FilterList(Operator.MUST_PASS_ONE,Arrays.asList(filter1));
            
            scan.setFilter(filterList);
            HTable htable  = getHTable(tableName);
            
            ResultScanner rs = htable.getScanner(scan);
            htable.close();
            return rs;
        }
        
    }

      测试:

    package cn.luxh.app.test;
    
    import java.io.IOException;
    import java.util.ArrayList;
    import java.util.List;
    
    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.client.ResultScanner;
    import org.apache.hadoop.hbase.util.Bytes;
    import org.junit.Test;
    
    import cn.luxh.app.util.HBaseUtil;
    
    public class HBaseTester {
        
        //测试创建表
        @Test
        public void testCreateTable() throws IOException {
            HBaseUtil.createTable("user", "username","password");
        }
        
        //测试插入数据
        @Test
        public void testInsertData() throws IOException {
            HTable htable = HBaseUtil.getHTable("user");
            List<Put> puts = new ArrayList<Put>();;
            Put put1 = HBaseUtil.getPut("1", "username", null, "chuliuxiang");
            puts.add(put1);
            Put put2 = HBaseUtil.getPut("1", "password", null, "654321");
            puts.add(put2);
            htable.setAutoFlush(false);
            htable.put(puts);
            htable.flushCommits();
            htable.close();
        }
        
        //测试获取一行数据
        @Test
        public void testGetRow() throws IOException {
            Result result = HBaseUtil.getResult("user", "1");
            byte[] userName = result.getValue("username".getBytes(), null);
            byte[] password = result.getValue("password".getBytes(), null);
            System.out.println("username is: "+Bytes.toString(userName)+" passwd is :"+Bytes.toString(password));
        }
        
        //测试条件查询
        @Test
        public void testScan() throws IOException {
            ResultScanner rs = HBaseUtil.getResultScanner("user", "username","chuliuxiang","1","10");
            for(Result r : rs) {
                System.out.println(Bytes.toString(r.getValue(Bytes.toBytes("username"), null)));
            }
        }
    }
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  • 原文地址:https://www.cnblogs.com/luxh/p/3025172.html
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