HBase API操作
环境准备
新建项目后在pom.xml中添加依赖：
<dependency>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-server</artifactId>
<version>1.3.1</version>
</dependency>
<dependency>
<groupId>org.apache.hbase</groupId>
<artifactId>hbase-client</artifactId>
<version>1.3.1</version>
</dependency>
HBaseAPI
测试代码
package com.dev1.demo01;
public class TestHBase {
@Test
public void test01() throws Exception {
//需要定义一个工具类，调用它的静态方法，等价于一个shell指令
Configuration conf = HBaseUtil.getConf();
System.out.println(conf);
//判断一张表是否存在
boolean flag = HBaseUtil.isExist("t2");
System.out.println(flag);
//先调用再实现
HBaseUtil.createTable("student","info");
//删除表
//HBaseUtil.dropTable("student");
}
@Test
public void test02() throws Exception {
HBaseUtil.putRow("student","10002","info","name","rose");
}
@Test
public void test03() throws Exception {
HBaseUtil.deleteRow("student","10001");
}
@Test
public void test04() throws Exception {
HBaseUtil.printRows("student");
}
@Test
public void test05() throws Exception {
HBaseUtil.printOneRow("student","10001");
HBaseUtil.printOneRow("student","10002");
}
@Test
public void test06() throws Exception {
HBaseUtil.printOneRow2("student","10001","info","age");
}
@Test
public void test07() throws Exception {
}
}
工具类代码
package com.dev1.util;
public class HBaseUtil {
//配置信息hdfs core-site.xml hdfs-site.xml
public static Configuration conf;
public static Connection connection;
static{
//使用HBaseConfiguration的单例方法实例化
conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum", "192.168.26.102");
conf.set("hbase.zookeeper.property.clientPort", "2181");
try {
connection = ConnectionFactory.createConnection(conf);//返回一个可以使用的连接
} catch (IOException e) {
e.printStackTrace();
}
}
public static Configuration getConf() {
return conf;
}
//判断一个表是否存在
public static boolean isExist(String tableName)throws Exception{
//HBaseAdmin admin = new HBaseAdmin(conf);或时
Admin admin = connection.getAdmin(); //获取表的管理对象，创建，删表，查表
return admin.tableExists(TableName.valueOf(tableName));
}
public static void createTable(String tableName, String... columnFamily) throws Exception {
//管理表
//HBaseAdmin admin = new HBaseAdmin(conf);
Admin admin = connection.getAdmin(); //获取表的管理对象，创建，删表，查表
//判断表是否存在，如果不存在才创建
if(!isExist(tableName)){
//创建表 表的描述 表的元数据
HTableDescriptor desc = new HTableDescriptor(TableName.valueOf(tableName));
//因为可能存在多个列，所以使用循环
for(String column:columnFamily){
//列族的元数据
HColumnDescriptor hcd = new HColumnDescriptor(column);
desc.addFamily(hcd);
}
admin.createTable(desc);
}
}
//删除表，必须先禁用表，然后才能删除表
public static void dropTable(String tableName) throws Exception{
// HBaseAdmin admin = new HBaseAdmin(conf);
Admin admin = connection.getAdmin(); //获取表的管理对象，创建，删表，查表
//如果表存在，我们才能进行删除
if(isExist(tableName)){
//禁用
admin.disableTable(TableName.valueOf(tableName));
//删除
admin.deleteTable(TableName.valueOf(tableName));
}
}
public static void putRow(String tableName, String rowKey, String columnFamily, String name, String value) throws Exception {
//创建HTable对象
//HTable hTable = new HTable(conf, tableName);
Table hTable = connection.getTable(TableName.valueOf(tableName));
//向表中插入数据
Put put = new Put(Bytes.toBytes(rowKey));
//向Put对象中组装数据
put.add(Bytes.toBytes(columnFamily), Bytes.toBytes(name), Bytes.toBytes(value));
hTable.put(put);
hTable.close();
}
public static void deleteRow(String tableName, String...rows) throws Exception {
// HTable hTable = new HTable(conf, tableName);
Table hTable = connection.getTable(TableName.valueOf(tableName));
List<Delete> deleteList = new ArrayList<Delete>();
for(String row : rows){
Delete delete = new Delete(Bytes.toBytes(row));
deleteList.add(delete);
}
hTable.delete(deleteList);
hTable.close();
}
public static void printRows(String tableName)throws Exception {
//select * from student
//scan 'student'
//HTable hTable = new HTable(conf, tableName);
Table hTable = connection.getTable(TableName.valueOf(tableName));
//创建扫描器
Scan scan = new Scan();
//扫描 代表查询的结果 ResultScanner
ResultScanner results = hTable.getScanner(scan);
for(Result result:results){
//Result相当于一个行
print(result);
}
}
//打印一行的代码是一样的，只需要传入表示一行的Result对象 就可以
//不使用复制代码，而使用封装方法
private static void print(Result result) {
//Cell当前行的一个单元格
Cell[] cells = result.rawCells();
for(Cell cell:cells){
//打印 行键
System.out.print(Bytes.toString(CellUtil.cloneRow(cell))+" | ");
//列族
System.out.print(Bytes.toString(CellUtil.cloneFamily(cell))+" | ");
//列标识
System.out.print(Bytes.toString(CellUtil.cloneQualifier(cell))+" | ");
//值
System.out.println(Bytes.toString(CellUtil.cloneValue(cell)));
System.out.println("-----------------");
}
}
public static void printOneRow(String tableName, String rowkey) throws Exception{
HTable hTable = new HTable(conf, tableName);
//get 'student','10001'
//Get对象表示查询一条记录
Get get = new Get(Bytes.toBytes(rowkey));
Result result = hTable.get(get);
print(result);
}
public static void printOneRow2(String tableName, String rowKey, String family, String column) throws Exception{
HTable hTable = new HTable(conf, tableName);
//get 'student','1001','info:name'
//Get对象表示查询一条记录
Get get = new Get(Bytes.toBytes(rowKey));
//指定列族下的一个列的值
get.addColumn(Bytes.toBytes(family),Bytes.toBytes(column));
Result result = hTable.get(get);
print(result);
}
}
