用 Java 对 hbase 进行CRUD增删改查操作

时间:2023-01-05 08:34:30

本文以HBase 0.90.2为例,介绍如何在Windows系统,Eclipse IDE集成环境下,使用Java语言,进行HBase客户端编程,包含建立表、删除表、插入记录、删除记录、各种方式下的查询操作等。

1. 准备工作

1、下载后安装jdk包(这里使用的是jdk-6u10-rc2-bin-b32-windows-i586-p-12_sep_2008);

2、下载eclipse,解压到本地(这里使用的是eclipse-java-helios-SR2-win32);

3、下载HBase包,解压安装包到本地(这里使用的是hbase-0.90.2)。

2. 搭建开发环境

1、运行Eclipse,创建一个新的Java工程“HBaseClient”,右键项目根目录,选择“Properties”->“Java Build Path”->“Library”->“Add External JARs”,将HBase解压后根目录下的hbase-0.90.2.jar、hbase-0.90.2-tests.jar和lib子目录下所有jar包添加到本工程的Classpath下。

2、按照步骤1中的操作,将自己所连接的HBase的配置文件hbase-site.xml添加到本工程的Classpath中,如下所示为配置文件的一个示例。

123456789101112131415161718 <configuration><property><name>hbase.rootdir</name><value> hdfs://hostname:9000/hbase </value></property><property><name>hbase.cluster.distributed</name><value>true</value></property><property><name>hbase.zookeeper.quorum</name><value>*.*.*.*, *.*.*.*, *.*.*.*</value></property><propertyskipInDoc="true"><name>hbase.defaults.for.version</name><value>0.90.2</value></property></configuration>

3、下面可以在Eclipse环境下进行HBase编程了。

3. HBase基本操作代码示例

?
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137 import
java.io.IOException;
import
java.util.ArrayList;
import
java.util.List;
 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.MasterNotRunningException;
import
org.apache.hadoop.hbase.ZooKeeperConnectionException;
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.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
CreateTable {
    private
static
Configuration conf = null;
    // 初始化配置    static
{
        conf = HBaseConfiguration.create();    }     // 1、建表    public
static
void createTable(String tablename, String[] cfs)
            throws
IOException {
        HBaseAdmin admin = new
HBaseAdmin(conf);
        if
(admin.tableExists(tablename)) {
            System.out.println("表已经存在!");        }else
{
            HTableDescriptor tableDesc = new
HTableDescriptor(tablename);
            for
(
int
i =
0; i < cfs.length; i++) {
                // 表建好后,列簇不能动态增加,而列是可以动态增加的,这是hbase伸缩性的一个体现。                tableDesc.addFamily(new
HColumnDescriptor(cfs[i]));
            }            admin.createTable(tableDesc);            System.out.println("表创建成功!");        }    }     // 2、插入数据    public
static
void writeRow(String tablename, String[] cfs) {
        try
{
            HTable table = new
HTable(conf, tablename);
            Put put = new
Put(Bytes.toBytes(
"rows1"));
            for
(
int
j =
0; j < cfs.length; j++) {
                put.add(Bytes.toBytes(cfs[j]),// 指定列簇                        Bytes.toBytes(String.valueOf("列1")),// 指定列名                        Bytes.toBytes("value_13"));// 指定列值                put.add(Bytes.toBytes(cfs[j]),                        Bytes.toBytes(String.valueOf("lie2")),                        Bytes.toBytes("value_24"));                table.put(put);                System.out.println("插入数据成功");            }        }catch
(IOException e) {
            e.printStackTrace();        }    }     // 3、删除一行数据    public
static
void deleteRow(String tablename, String rowkey)
            throws
IOException {
        HTable table = new
HTable(conf, tablename);
        List list = new
ArrayList();
        Delete d1 = new
Delete(rowkey.getBytes());
        list.add(d1);        table.delete(list);        System.out.println("删除行成功!");    }     // 4、查找一行数据    public
static
void selectRow(String tablename, String rowKey)
            throws
IOException {
        HTable table = new
HTable(conf, tablename);
        Get g = new
Get(rowKey.getBytes());
        Result rs = table.get(g);        for
(KeyValue kv : rs.raw()) {
            System.out.print(new
String(kv.getRow()) +
"  ");// 行号
            System.out.print(new
String(kv.getFamily()) +
":");// 列簇名
            System.out.print(new
String(kv.getQualifier()) +
"  ");// 列名
            System.out.print(kv.getTimestamp() + "  ");// 时间戳            System.out.println(new
String(kv.getValue()));
// 单元格的值
        }    }     // 5、查找全部数据    public
static
void scanerTable(String tablename) {
        try
{
            HTable table = new
HTable(conf, tablename);
            Scan s = new
Scan();
            ResultScanner rs = table.getScanner(s);            for
(Result r : rs) {
                KeyValue[] kv = r.raw();                for
(
int
i =
0; i < kv.length; i++) {
                    System.out.print(new
String(kv[i].getRow()) +
"  ");
                    System.out.print(new
String(kv[i].getFamily()) +
":");
                    System.out.print(new
String(kv[i].getQualifier()) +
"  ");
                    System.out.print(kv[i].getTimestamp() + "  ");                    System.out.println(new
String(kv[i].getValue()));
                }            }        }catch
(IOException e) {
            e.printStackTrace();        }    }     // 6、删除表    public
static
void deleteTable(String tablename) throws
IOException {
        try
{
            HBaseAdmin admin = new
HBaseAdmin(conf);
            admin.disableTable(tablename);            admin.deleteTable(tablename);            System.out.println("表删除成功!");        }catch
(MasterNotRunningException e) {
            e.printStackTrace();        }catch
(ZooKeeperConnectionException e) {
            e.printStackTrace();        }    }     public
static
void main(String[] args) throws
IOException {
         String[] cfs = "a,b,c".split(",");        // createTable("test01", cfs);        // writeRow("test01", cfs);        // deleteRow("test01", "rows1");        // selectRow("test01", "rows2");        // scanerTable("test01");        // deleteTable("test01");    }}

REF:

【Hbase】Java对hbase的操作

http://smallwildpig.iteye.com/blog/1695203