HBase Java客户端编程
HBase Java客户端编程
本文以Hbase-0.92.0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;
2、下载eclipse,解压到本地;
3、下载HBase包,解压安装包到本地(这里使用的是 Hbase-0.92.0)。
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-0.92.0.jar、hbase-0.92.0-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:
- <configuration>
- <property>
- <name>hbase.rootdir</name>
- <value>hdfs://Hadoop-1:9000/hbase</value>
- </property>
- <property>
- <name>hbase.cluster.distributed</name>
- <value>true</value>
- </property>
- <property>
- <name>hbase.zookeeper.quorum</name>
- <value>hadoop-1,hadoop-2,hadoop-3,hadoop-4</value>
- </property>
- <property>
- <name>zookeeper.session.timeout</name>
- <value>60000</value>
- </property>
- <property>
- <name>hbase.master</name>
- <value>hadoop-1:60000</value>
- </property>
- <property>
- <name>hbase.zookeeper.property.clientPort</name>
- <value>21818</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
- 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.Result;
- import org.apache.hadoop.hbase.client.ResultScanner;
- import org.apache.hadoop.hbase.client.Scan;
- import org.apache.hadoop.hbase.client.Put;
- import org.apache.hadoop.hbase.util.Bytes;
- public class HBaseTest {
- private static Configuration conf =null;
- /**
- * 初始化配置
- */
- static {
- conf = HBaseConfiguration.create();
- }
- /**
- * 创建一张表
- */
- public static void creatTable(String tableName, String[] familys) throws Exception {
- HBaseAdmin admin = new HBaseAdmin(conf);
- if (admin.tableExists(tableName)) {
- System.out.println("table already exists!");
- } else {
- HTableDescriptor tableDesc = new HTableDescriptor(tableName);
- for(int i=0; i<familys.length; i++){
- tableDesc.addFamily(new HColumnDescriptor(familys[i]));
- }
- admin.createTable(tableDesc);
- System.out.println("create table " + tableName + " ok.");
- }
- }
- /**
- * 删除表
- */
- public static void deleteTable(String tableName) throws Exception {
- try {
- HBaseAdmin admin = new HBaseAdmin(conf);
- admin.disableTable(tableName);
- admin.deleteTable(tableName);
- System.out.println("delete table " + tableName + " ok.");
- } catch (MasterNotRunningException e) {
- e.printStackTrace();
- } catch (ZooKeeperConnectionException e) {
- e.printStackTrace();
- }
- }
- /**
- * 插入一行记录
- */
- public static void addRecord (String tableName, String rowKey, String family, String qualifier, String value)
- throws Exception{
- try {
- HTable table = new HTable(conf, tableName);
- Put put = new Put(Bytes.toBytes(rowKey));
- put.add(Bytes.toBytes(family),Bytes.toBytes(qualifier),Bytes.toBytes(value));
- table.put(put);
- System.out.println("insert recored " + rowKey + " to table " + tableName +" ok.");
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- /**
- * 删除一行记录
- */
- public static void delRecord (String tableName, String rowKey) throws IOException{
- HTable table = new HTable(conf, tableName);
- List list = new ArrayList();
- Delete del = new Delete(rowKey.getBytes());
- list.add(del);
- table.delete(list);
- System.out.println("del recored " + rowKey + " ok.");
- }
- /**
- * 查找一行记录
- */
- public static void getOneRecord (String tableName, String rowKey) throws IOException{
- HTable table = new HTable(conf, tableName);
- Get get = new Get(rowKey.getBytes());
- Result rs = table.get(get);
- for(KeyValue kv : rs.raw()){
- System.out.print(new String(kv.getRow()) + " " );
- System.out.print(new String(kv.getFamily()) + ":" );
- System.out.print(new String(kv.getQualifier()) + " " );
- System.out.print(kv.getTimestamp() + " " );
- System.out.println(new String(kv.getValue()));
- }
- }
- /**
- * 显示所有数据
- */
- public static void getAllRecord (String tableName) {
- try{
- HTable table = new HTable(conf, tableName);
- Scan s = new Scan();
- ResultScanner ss = table.getScanner(s);
- for(Result r:ss){
- for(KeyValue kv : r.raw()){
- System.out.print(new String(kv.getRow()) + " ");
- System.out.print(new String(kv.getFamily()) + ":");
- System.out.print(new String(kv.getQualifier()) + " ");
- System.out.print(kv.getTimestamp() + " ");
- System.out.println(new String(kv.getValue()));
- }
- }
- } catch (IOException e){
- e.printStackTrace();
- }
- }
- public static void main (String [] agrs) {
- try {
- String tablename = "scores";
- String[] familys = {"grade", "course"};
- HBaseTest.creatTable(tablename, familys);
- //add record zkb
- HBaseTest.addRecord(tablename,"zkb","grade","","5");
- HBaseTest.addRecord(tablename,"zkb","course","","90");
- HBaseTest.addRecord(tablename,"zkb","course","math","97");
- HBaseTest.addRecord(tablename,"zkb","course","art","87");
- //add record baoniu
- HBaseTest.addRecord(tablename,"baoniu","grade","","4");
- HBaseTest.addRecord(tablename,"baoniu","course","math","89");
- System.out.println("===========get one record========");
- HBaseTest.getOneRecord(tablename, "zkb");
- System.out.println("===========show all record========");
- HBaseTest.getAllRecord(tablename);
- System.out.println("===========del one record========");
- HBaseTest.delRecord(tablename, "baoniu");
- HBaseTest.getAllRecord(tablename);
- System.out.println("===========show all record========");
- HBaseTest.getAllRecord(tablename);
- } catch (Exception e) {
- e.printStackTrace();
- }
- }
- }
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