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:
- <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>
- <property skipInDoc="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
3.1 初始化配置
1 privatestatic Configuration conf =null;
2 /**
3 * 初始化配置
4 */
5 static {
6 conf = HBaseConfiguration.create();
7 }
3.2 创建表
- /**
- * 创建表操作
- * @throws IOException
- */
- publicvoid 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++) {
- tableDesc.addFamily(new HColumnDescriptor(cfs[i]));
- }
- admin.createTable(tableDesc);
- System.out.println("表创建成功!");
- }
- }
3.3 删除表
1 /**
2 * 删除表操作
3 * @param tablename
4 * @throws IOException
5 */
6 publicvoid deleteTable(String tablename) throws IOException {
7 try {
8 HBaseAdmin admin =new HBaseAdmin(conf);
9 admin.disableTable(tablename);
10 admin.deleteTable(tablename);
11 System.out.println("表删除成功!");
12 } catch (MasterNotRunningException e) {
13 e.printStackTrace();
14 } catch (ZooKeeperConnectionException e) {
15 e.printStackTrace();
16 }
17 }
3.4 插入一行记录
- /**
- * 插入一行记录
- * @param tablename
- * @param cfs
- */
- publicvoid 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]),
- Bytes.toBytes(String.valueOf(1)),
- Bytes.toBytes("value_1"));
- table.put(put);
- }
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
3.5 删除一行记录
1 /**
2 * 删除一行记录
3 * @param tablename
4 * @param rowkey
5 * @throws IOException
6 */
7 publicvoid deleteRow(String tablename, String rowkey) throws IOException {
8 HTable table =new HTable(conf, tablename);
9 List list =new ArrayList();
10 Delete d1 =new Delete(rowkey.getBytes());
11 list.add(d1);
12 table.delete(list);
13 System.out.println("删除行成功!");
14 }
3.6 查找一行记录
- /**
- * 查找一行记录
- * @param tablename
- * @param rowkey
- */
- publicstaticvoid 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()) +"");
- 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()));
- }
- }
3.7 查询表中所有行
1 /**
2 * 查询表中所有行
3 * @param tablename
4 */
5 publicvoid scaner(String tablename) {
6 try {
7 HTable table =new HTable(conf, tablename);
8 Scan s =new Scan();
9 ResultScanner rs = table.getScanner(s);
10 for (Result r : rs) {
11 KeyValue[] kv = r.raw();
12 for (int i =0; i < kv.length; i++) {
13 System.out.print(new String(kv[i].getRow()) +"");
14 System.out.print(new String(kv[i].getFamily()) +":");
15 System.out.print(new String(kv[i].getQualifier()) +"");
16 System.out.print(kv[i].getTimestamp() +"");
17 System.out.println(new String(kv[i].getValue()));
18 }
19 }
20 } catch (IOException e) {
21 e.printStackTrace();
22 }
23 }
转自:http://www.cnblogs.com/panfeng412/archive/2011/08/14/2137984.html
第二个例子
package com.hbase; 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 HbaseClient { private static Configuration conf = null; /** * hbase-0.90.3 * 初始化配置 */ static { conf = HBaseConfiguration.create(); conf.set("hbase.master", "192.168.27.12"); } /** * 创建表操作 * * @throws IOException */ public 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++) { tableDesc.addFamily(new HColumnDescriptor(cfs[i])); } admin.createTable(tableDesc); System.out.println(" 表创建成功!"); } } /** * 删除表操作 * * @param tablename * @throws IOException */ public void deleteTable(String tablename) throws IOException { try { HBaseAdmin admin = new HBaseAdmin(conf); if (!admin.tableExists(tablename)) { System.out.println("表不存在, 无需进行删除操作!"); }else{ 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 void insertRow() throws Exception{ HTable table = new HTable(conf, "test"); Put put = new Put(Bytes.toBytes("row3")); put.add(Bytes.toBytes("cf"), Bytes.toBytes("444"), Bytes.toBytes("value444")); table.put(put); } /** * 插入一行记录 * * @param tablename * @param cfs */ public void writeRow(String tablename, String[] cfs) { try { HTable table = new HTable(conf, tablename); Put put = new Put(Bytes.toBytes("rows3")); for (int j = 0; j < cfs.length; j++) { put.add(Bytes.toBytes(cfs[j]), Bytes.toBytes(cfs[j]+String.valueOf(1)), Bytes.toBytes(cfs[j]+"value")); table.put(put); } System.out.println("写入成功!"); } catch (IOException e) { e.printStackTrace(); } } //写多条记录 public void writeMultRow(String tablename, String[][] cfs) { try { HTable table = new HTable(conf, tablename); List<Put> lists = new ArrayList<Put>(); for (int i = 0; i < cfs.length; i++) { Put put = new Put(Bytes.toBytes(cfs[i][0])); put.add(Bytes.toBytes(cfs[i][1]), Bytes.toBytes(cfs[i][2]), Bytes.toBytes(cfs[i][3])); lists.add(put); } table.put(lists); System.out.println("写入成功!"); } catch (IOException e) { e.printStackTrace(); } } /** * 删除一行记录 * * @param tablename * @param rowkey * @throws IOException */ public void deleteRow(String tablename, String rowkey) throws IOException { HTable table = new HTable(conf, tablename); List<Delete> list = new ArrayList<Delete>(); Delete d1 = new Delete(rowkey.getBytes()); list.add(d1); table.delete(list); System.out.println("删除行成功!"); } /** * 查找一行记录 * * @param tablename * @param rowkey */ public static void selectRow(String tablename, String rowKey) throws IOException { HTable table = new HTable(conf, tablename); Get g = new Get(rowKey.getBytes()); // g.addColumn(Bytes.toBytes("cf:1")); Result rs = table.get(g); 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())); } } /** * 查询表中所有行 * * @param tablename */ public void scaner(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(); } } public static void main(String[] args) throws Exception { HbaseClient cli = new HbaseClient(); //删除表 cli.deleteTable("test"); //创建表 cli.createTable("test", new String[]{"cf"}); //写多条记录 cli.writeMultRow("test", new String[][]{{"rows1","cf","1","value1"},{"rows1","cf","2","value2"},{"rows2","cf","2","value2"}}); //写一条记录 cli.writeRow("test", new String[]{"cf"}); System.out.println("\n查询一个rows1:"); selectRow("test", "rows1"); System.out.println("\n查询所有:"); cli.scaner("test"); } }