Hbase常用操作(增删改查)
HBase提供了java api来对HBase进行一系列的管理涉及到对表的管理、数据的操作等。常用的API操作有：
1、 对表的创建、删除、显示以及修改等，可以用HBaseAdmin，一旦创建了表，那么可以通过HTable的实例来访问表，每次可以往表里增加数据。
2、 插入数据
创建一个Put对象，在这个Put对象里可以指定要给哪个列增加数据，以及当前的时间戳等值，然后通过调用HTable.put(Put)来提交操作，在这里提请注意的是：在创建Put对象的时候，你必须指定一个行(Row)值，在构造Put对象的时候作为参数传入。
3、 获取数据
要获取数据，使用Get对象，Get对象同Put对象一样有好几个构造函数，通常在构造的时候传入行值，表示取第几行的数据，通过HTable.get(Get)来调用。
4、 浏览每一行
通过Scan可以对表中的行进行浏览，得到每一行的信息，比如列名，时间戳等，Scan相当于一个游标，通过next()来浏览下一个，通过调用HTable.getScanner(Scan)来返回一个ResultScanner对象。HTable.get(Get)和HTable.getScanner(Scan)都是返回一个Result。Result是一个Key/Value的链表。
5、 删除
使用Delete来删除记录，通过调用HTable.delete(Delete)来执行删除操作。（注：删除这里有些特别，也就是删除并不是马上将数据从表中删除。）
6、 锁
新增、获取、删除在操作过程中会对所操作的行加一个锁，而浏览却不会。
7、 簇的访问
客户端代码通过ZooKeeper来访问找到簇，也就是说ZooKeeper quorum将被使用，那么相关的类（包）应该在客户端的类（classes）目录下，即客户端一定要找到文件hbase-site.xml。
新建一个类：
package com.jhl.hbase;
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.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 OperateTable {
private static Configuration conf = null;
static {
conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum", "master");// 使用eclipse时必须添加这个，否则无法定位
conf.set("hbase.zookeeper.property.clientPort", "2181");
}
// 创建数据库表
@SuppressWarnings("deprecation")
public static void createTable(String tableName, String[] columnFamilys)
throws Exception {
HBaseAdmin hadmin = new HBaseAdmin(conf);
if (hadmin.tableExists(tableName)) {
System.out.println("表已存在");
System.exit(0);
} else {
// 新建一个 表的描述
HTableDescriptor tableDesc = new HTableDescriptor(tableName);
// 在描述里添加列族
for (String columnFamily : columnFamilys) {
tableDesc.addFamily(new HColumnDescriptor(columnFamily));
}
// 根据配置好的描述建表
hadmin.createTable(tableDesc);
System.out.println("创建表成功！");
}
}
// 删除数据库表
public static void deleteTable(String tableName) throws Exception {
HBaseAdmin hadmin = new HBaseAdmin(conf);
if (hadmin.tableExists(tableName)) {
// 关闭表
hadmin.disableTable(tableName);
hadmin.deleteTable(tableName);
System.out.println("删除表成功！");
} else {
System.out.println("删除的表不存在");
System.exit(0);
}
}
// 添加一条数据
public static void addRow(String tableName, String row,
String columnFamily, String column, String value) throws Exception {
HTable hTable = new HTable(conf, tableName);
Put put = new Put(Bytes.toBytes(row));
// 参数出分别：列族、列、值
put.add(Bytes.toBytes(columnFamily), Bytes.toBytes(column),
Bytes.toBytes(value));
hTable.put(put);
}
// 删除一条数据
public static void delRow(String tableName, String row) throws Exception {
HTable hTable = new HTable(conf, tableName);
Delete delete = new Delete(Bytes.toBytes(row));
hTable.delete(delete);
}
// 删除多条数据
public static void delMultiRows(String tableName, String[] rows)
throws Exception {
HTable hTable = new HTable(conf, tableName);
List<Delete> list = new ArrayList<Delete>();
for (String row : rows) {
Delete delete = new Delete(Bytes.toBytes(row));
list.add(delete);
}
hTable.delete(list);
}
// get row
public static void getRow(String tableName, String row) throws Exception {
HTable hTable = new HTable(conf, tableName);
Get get = new Get(Bytes.toBytes(row));
Result result = hTable.get(get);
for (KeyValue rowkv : result.raw()) {
System.out.print("Row Name: " + new String(rowkv.getRow()) + " ");
System.out.print("Timestamp: " + rowkv.getTimestamp() + " ");
System.out.print("column Family: " + new String(rowkv.getFamily())
+ " ");
System.out.print("Row Name: " + new String(rowkv.getQualifier())
+ " ");
System.out.println("Value: " + new String(rowkv.getValue()) + " ");
}
}
// get filter row
public static void getFilterRow(String tableName, String row) throws Exception {
HTable hTable = new HTable(conf, tableName);
Get get = new Get(Bytes.toBytes(row));
ByteArrayComparable qualifierComparator = new SubstringComparator("course");
Filter filter = new QualifierFilter(CompareOp.LESS_OR_EQUAL, qualifierComparator);
get.setFilter(filter);
Result result = hTable.get(get);
System.out.println("result= " + result);
for (KeyValue rowkv : result.raw()) {
System.out.print("Row Name: " + new String(rowkv.getRow()) + " ");
System.out.print("Timestamp: " + rowkv.getTimestamp() + " ");
System.out.print("column Family: " + new String(rowkv.getFamily())
+ " ");
System.out.print("Row Name: " + new String(rowkv.getQualifier())
+ " ");
System.out.println("Value: " + new String(rowkv.getValue()) + " ");
}
}
// get all records
public static void getAllRows(String tableName) throws Exception {
HTable hTable = new HTable(conf, tableName);
Scan scan = new Scan();
ResultScanner results = hTable.getScanner(scan);
for (Result result : results) {
for (KeyValue rowKV : result.raw()) {
System.out.print("Row Name: " + new String(rowKV.getRow())
+ " ");
System.out.print("Timestamp: " + rowKV.getTimestamp() + " ");
System.out.print("column Family: "
+ new String(rowKV.getFamily()) + " ");
System.out.print("Row Name: "
+ new String(rowKV.getQualifier()) + " ");
System.out.println("Value: " + new String(rowKV.getValue())
+ " ");
}
}
}
public static void main(String[] args) {
String tableName = "score";
String[] columnFamilys = { "info", "course" };
try {
// OperateTable.createTable(tableName, columnFamilys);
// OperateTable.deleteTable(tableName);
// 添加第一行数据
// OperateTable.addRow(tableName, "tht", "info", "age", "20");
// OperateTable.addRow(tableName, "tht", "info", "sex", "boy");
// OperateTable.addRow(tableName, "tht", "course", "china", "97");
// OperateTable.addRow(tableName, "tht", "course", "math", "128");
// OperateTable.addRow(tableName, "tht", "course", "english", "85");
// 添加第二行数据
// OperateTable.addRow(tableName, "xiaoxue", "info", "age", "19");
// OperateTable.addRow(tableName, "xiaoxue", "info", "sex", "boy");
// OperateTable.addRow(tableName, "xiaoxue", "course", "china", "90");
// OperateTable.addRow(tableName, "xiaoxue", "course", "math", "120");
// OperateTable.addRow(tableName, "xiaoxue", "course", "english", "90");
// 添加第三行数据
// OperateTable.addRow(tableName, "qingqing", "info", "age", "18");
// OperateTable.addRow(tableName, "qingqing", "info", "sex", "girl");
// OperateTable.addRow(tableName, "qingqing", "course", "china", "100");
// OperateTable.addRow(tableName, "qingqing", "course", "math","100");
// OperateTable.addRow(tableName, "qingqing", "course", "english","99");
// OperateTable.getRow(tableName, "xiaoxue");
// OperateTable.getAllRows(tableName);
// OperateTable.delRow(tableName, "tht");
String[] rows = { "xiaoxue", "qingqing" };
OperateTable.delMultiRows(tableName, rows);
OperateTable.getFilterRow(tableName, "tht");
} catch (Exception e) {
e.printStackTrace();
}
}
}