package com.zoujc.Utils;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.filter.*;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.io.IOUtils;
/**
* javaAPI操作HBase get put namespace scan filter cache
*/
public class HBaseTest {
static Configuration conf = null;
static {
conf = HBaseConfiguration.create();
conf.set("hbase.zookeeper.quorum", "node1:2181,node2:2181,node3:2181");
conf.set("hbase.rootdir","hdfs://hadoopcluster/hbase");
}
public static void main(String[] args){
/**createNamespace("ns1");
* createTable("apitable","info");
* addColumnFamily("apitable","secret");
* putData("apitable","1","info","name","sid");
* putData("apitable","1","info","age","27");
* putData("apitable","1","secret","idcart","123");
* putData("apitable","2","info","age","28");
* putData("apitable","2","info","name","zhangsi");
* putData("apitable","3","info","name","lisi");
* putData("apitable","3","info","school","cqut");
* putData("apitable","4","info","name","wangwu");
* getData("apitable","1","info","name");*/
//scanData("apitable","1","3","info");
// filter("apitable","1");
}
/**
* 创建namespace
*/
public static void createNamespace(String namespace) throws Exception{
HBaseAdmin admin = new HBaseAdmin(conf);
//创建namespace
NamespaceDescriptor descriptor = NamespaceDescriptor.create(namespace).build();
admin.createNamespace(descriptor);
admin.close();
}
/**
* put
*/
public static void putData(String tableName, String rowKey, String columnFamily, String column, String value) throws Exception{
HTable table = getTable(tableName);
Put put = new Put(Bytes.toBytes(rowKey));
put.add(Bytes.toBytes(columnFamily),Bytes.toBytes(column),Bytes.toBytes(value));
table.put(put);
table.close();
}
/**
* get
*/
public static void getData(String tableName,String rowKey,String columnFamily,String column) throws Exception{
HTable table = getTable(tableName);
//一定要知道rowKey
Get get = new Get(Bytes.toBytes(rowKey));
Result result = table.get(get);
//在知道列名和列族的情况下指定单元格
byte[] value = result.getValue(Bytes.toBytes(columnFamily),Bytes.toBytes(column));
System.out.println(new String(value));
//在只知道rowkey的情况下,遍历每个单元格
printResult(result);
//System.out.println(new String(cell.getFamily())+":"+new String(cell.getQualifier())+":"+new String(cell.getValue()));
}
/**
* scan
* 一个Result是一行数据
* ResultScanner是多行数据
* */
public static void scanData(String tableName,String startRowKey,String stopRowKey,String columnFamily){
HTable table = null;
try {
table = getTable(tableName);
//全表扫描
Scan scan = new Scan();
//根据rowkey范围查询 开始是包括这个rowkey 结束是不包括这个rowkey
scan.setStartRow(Bytes.toBytes(startRowKey));
scan.setStopRow(Bytes.toBytes(stopRowKey));
//查询指定列族下的
scan.addFamily(Bytes.toBytes(columnFamily));
//是否本地缓存
scan.setCacheBlocks(false); //默认是true
//面向列的缓存,每次返回3列
scan.setBatch(3);
//面向行的缓存 每次返回的行有2行 如果一共有10行数据,那么就会读取5次
scan.setCaching(2);
//权限设置
//scan.setACL();
ResultScanner results = table.getScanner(scan);
for(Result rs: results){
printResult(rs);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if(table != null){
IOUtils.closeStream(table);
}
}
}
//过滤器
public static void filter(String tableName,String prefix){
HTable table = null;
try {
table = getTable(tableName);
Scan scan = new Scan();
Filter filter = null;
//根据列的前缀查询 不是列族!
// filter = new ColumnPrefixFilter(Bytes.toBytes(prefix));
//根据rowkey的前缀查询!
// filter = new PrefixFilter(Bytes.toBytes(prefix));
//分页过滤,查询3条
// filter = new PageFilter(3);
//值比较
ByteArrayComparable comp = null;
//列族info的name的值为lisi 就查询出来
comp = new SubstringComparator("lisi");
filter = new SingleColumnValueExcludeFilter(Bytes.toBytes("info"),Bytes.toBytes("name"),CompareFilter.CompareOp.EQUAL,comp);
scan.setFilter(filter);
ResultScanner results = table.getScanner(scan);
for(Result rs: results){
printResult(rs);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if(table != null){
IOUtils.closeStream(table);
}
}
}
/**
* 打印出一行数据的每个单元格
*/
public static void printResult(Result rs){
for(Cell cell: rs.rawCells()){
System.out.println("row key :" + Bytes.toString(CellUtil.cloneRow(cell)));
System.out.println("column family :" + Bytes.toString(CellUtil.cloneFamily(cell)));
System.out.println("column name :" + Bytes.toString(CellUtil.cloneQualifier(cell)));
System.out.println("value :" + Bytes.toString(CellUtil.cloneValue(cell)));
}
}
/**
* 获取表
*/
public static HTable getTable(String tableName) throws Exception{
return new HTable(conf,Bytes.toBytes(tableName));
}
/**
* 创建表
*/
public static void createTable(String tableName,String columnFamily) throws Exception{
//hbase表结果操作的入口
HBaseAdmin admin = new HBaseAdmin(conf);
//判断表是否存在
boolean b = admin.tableExists(tableName);
if(b){
//禁用表
admin.disableTable(tableName);
//删除表
admin.deleteTable(tableName);
}
//设置表名
HTableDescriptor table = new HTableDescriptor(TableName.valueOf(tableName));
//设置列族
table.addFamily(new HColumnDescriptor(Bytes.toBytes(columnFamily)));
//创建表
admin.createTable(table);
admin.close();
}
/**
* 给已有的表添加列族
*/
public static void addColumnFamily(String tableName,String columnFamily) throws Exception{
//hbase表结果操作的入口
HBaseAdmin admin = new HBaseAdmin(conf);
//判断表是否存在
boolean b = admin.tableExists(tableName);
if(b){
//添加列族
admin.addColumn(tableName,new HColumnDescriptor(Bytes.toBytes(columnFamily)));
}
}
}
二:Java API操作HBase
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转载自blog.csdn.net/weixin_38799368/article/details/83114411
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