Hbase经常使用操做CRUD(增删改查)

时间 2019-12-14

标签 hbase 经常使用 crud 增删栏目 Hadoop 繁體版

原文原文链接

参考：java

http://blog.csdn.net/net19880504/article/details/17733161apache

运行Eclipse，建立一个新的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-0.94.1-security.jar、hbase-0.94.1-security-tests.jar和lib子目录下全部jar 包添加到本工程的Classpath下。api

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、数据的操做等。经常使用的API操做有：

　　一、对表的建立、删除、显示以及修改等，能够用HBaseAdmin，一旦建立了表，那么能够经过HTable的实例来访问表，每次能够往表里增长数据。

　　二、插入数据

　　　　建立一个Put对象，在这个Put对象里能够指定要给哪一个列增长数据，以及当前的时间戳等值，而后经过调用HTable.put(Put)来提交操做，子猴在这里提请注意的是：在建立Put对象的时候，你必须指定一个行(Row)值，在构造Put对象的时候做为参数传入。

　　三、获取数据

　　　　要获取数据，使用Get对象，Get对象同Put对象同样有好几个构造函数，一般在构造的时候传入行值，表示取第几行的数据，经过HTable.get(Get)来调用。

　　四、浏览每一行

　　　　经过Scan能够对表中的行进行浏览，获得每一行的信息，好比列名，时间戳等，Scan至关于一个游标，经过next()来浏览下一个，经过调用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

KeyValue的链表。

　　五、删除

　　　　使用Delete来删除记录，经过调用HTable.delete(Delete)来执行删除操做。（注：删除这里有些特别，也就是删除并非立刻将数据从表中删除。）

　　六、锁

　　　　新增、获取、删除在操做过程当中会对所操做的行加一个锁，而浏览却不会。

　　七、簇的访问

　　　　客户端代码经过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，即客户端必定要找到文件hbase-site.xml。函数

新建一个类：oop

  1 package com.hj.myhbase131;
  2 
  3 import java.io.IOException;
  4 import java.util.ArrayList;
  5 import java.util.List;
  6 
  7 import org.apache.hadoop.conf.Configuration;
  8 import org.apache.hadoop.hbase.client.Put;
  9 import org.apache.hadoop.hbase.client.Result;
 10 import org.apache.hadoop.hbase.client.ResultScanner;
 11 import org.apache.hadoop.hbase.client.Scan;
 12 import org.apache.hadoop.hbase.util.Bytes;
 13 import org.apache.hadoop.hbase.Cell;
 14 import org.apache.hadoop.hbase.CellUtil;
 15 import org.apache.hadoop.hbase.HBaseConfiguration;
 16 import org.apache.hadoop.hbase.HColumnDescriptor;
 17 import org.apache.hadoop.hbase.HTableDescriptor;
 18 import org.apache.hadoop.hbase.TableName;
 19 import org.apache.hadoop.hbase.client.Connection;
 20 import org.apache.hadoop.hbase.client.ConnectionFactory;
 21 import org.apache.hadoop.hbase.client.Delete;
 22 import org.apache.hadoop.hbase.client.Get;
 23 import org.apache.hadoop.hbase.client.HBaseAdmin;
 24 import org.apache.hadoop.hbase.client.HTable;
 25 
 26 /**
 27  * Hello world!
 28  *
 29  */
 30 public class App 
 31 {
 32     private static Configuration conf = null;
 33     private static Connection conn = null;
 34     
 35     static {
 36         conf = HBaseConfiguration.create();
 37         try {
 38             conn = ConnectionFactory.createConnection(conf);
 39         } catch (IOException e) {
 40             // TODO Auto-generated catch block
 41             e.printStackTrace();
 42         }
 43     }
 44     
 45     /**建立表
 46      * @param tableName
 47      * @param familys
 48      * @throws Exception
 49      */
 50     public static void creatTable(String tableName, String[] familys) throws Exception {
 51         HBaseAdmin admin = (HBaseAdmin) conn.getAdmin();
 52         if (admin.tableExists(tableName)) {
 53             System.out.println("table already exists");
 54         }else {
 55             HTableDescriptor tableDesc = new HTableDescriptor(TableName.valueOf(tableName));
 56             for (int i = 0; i < familys.length; i++) {
 57                 tableDesc.addFamily(new HColumnDescriptor(familys[i]));
 58             }
 59             admin.createTable(tableDesc);
 60             System.out.println("create table " + tableName + " ok."); 
 61         }
 62     }
 63     
 64     /**删除表
 65      * @param tableName
 66      * @throws Exception
 67      */
 68     public static void deleteTable(String tableName) throws Exception {
 69         HBaseAdmin admin = (HBaseAdmin) conn.getAdmin();
 70         admin.disableTable(tableName);
 71         admin.deleteTable(tableName);
 72         System.out.println("delete table " + tableName + " ok."); 
 73     }
 74          
 75     /**插入一行记录
 76      * @param tableName
 77      * @param rowKey
 78      * @param family
 79      * @param qualifier
 80      * @param value
 81      * @throws Exception
 82      */
 83     public static void addRecord (String tableName, String rowKey, String family, String qualifier, String value)       
 84             throws Exception{       
 85         try {       
 86             HTable table = (HTable) conn.getTable(TableName.valueOf(tableName));       
 87             Put put = new Put(Bytes.toBytes(rowKey));
 88             put.addColumn(Bytes.toBytes(family),Bytes.toBytes(qualifier),Bytes.toBytes(value));       
 89             table.put(put);       
 90             System.out.println("insert recored " + rowKey + " to table " + tableName +" ok.");       
 91         } catch (IOException e) {       
 92             e.printStackTrace();       
 93         }       
 94     }  
 95     
 96     /**    
 97      * 删除一行记录    
 98      */      
 99     public static void delRecord (String tableName, String rowKey) throws IOException{       
100         HTable table = (HTable) conn.getTable(TableName.valueOf(tableName));  
101         List <Delete>list = new ArrayList<Delete>();
102         Delete del = new Delete(rowKey.getBytes()); 
103         list.add(del);     
104         table.delete(list);       
105         System.out.println("del recored " + rowKey + " ok.");       
106     }       
107             
108     /**    
109      * 查找一行记录    
110      */      
111     public static void getOneRecord (String tableName, String rowKey) throws IOException{       
112         HTable table = (HTable) conn.getTable(TableName.valueOf(tableName));         
113         Get get = new Get(rowKey.getBytes());       
114         Result rs = table.get(get);       
115         for(Cell cell : rs.listCells()){       
116             // 一个Cell就是一个单元格，经过下面的方法能够得到这个单元格的各个值
117             System.out.print("行健: " + new String(CellUtil.cloneRow(cell)));
118             System.out.print("列簇: " + new String(CellUtil.cloneFamily(cell)));
119             System.out.print(" 列: " + new String(CellUtil.cloneQualifier(cell)));
120             System.out.print(" 值: " + new String(CellUtil.cloneValue(cell)));
121             System.out.println("时间戳: " + cell.getTimestamp());          
122         }       
123     }       
124             
125     /**    
126      * 显示全部数据    
127      */      
128     public static void getAllRecord (String tableName) {       
129         try{       
130              HTable table = (HTable) conn.getTable(TableName.valueOf(tableName));        
131              Scan s = new Scan();       
132              ResultScanner ss = table.getScanner(s);       
133              for(Result r:ss){       
134                  for(Cell cell : r.listCells()){       
135                      System.out.print(Bytes.toString(CellUtil.cloneRow(cell)) + " " );       
136                      System.out.print(Bytes.toString(CellUtil.cloneFamily(cell)) + ":" );       
137                      System.out.print(Bytes.toString(CellUtil.cloneQualifier(cell)) + " " );       
138                      System.out.println(Bytes.toString(CellUtil.cloneValue(cell)));          
139                  }      
140              }       
141         } catch (IOException e){       
142             e.printStackTrace();       
143         }       
144     }
145     
146     public static void main( String[] args ) throws Exception
147     {
148         try {       
149             String tablename = "scores";       
150             String[] familys = {"grade", "course"};       
151             App.creatTable(tablename, familys);       
152                     
153             //add record zkb       
154             App.addRecord(tablename,"zkb","grade","","5");       
155             App.addRecord(tablename,"zkb","course","","90");       
156             App.addRecord(tablename,"zkb","course","math","97");       
157             App.addRecord(tablename,"zkb","course","art","87");       
158             //add record  baoniu       
159             App.addRecord(tablename,"baoniu","grade","","4");       
160             App.addRecord(tablename,"baoniu","course","math","89");       
161                     
162             System.out.println("===========get one record========");       
163             App.getOneRecord(tablename, "zkb");       
164                     
165             System.out.println("===========show all record========");       
166             App.getAllRecord(tablename);       
167                     
168             System.out.println("===========del one record========");       
169             App.delRecord(tablename, "baoniu");       
170             App.getAllRecord(tablename);       
171                     
172             System.out.println("===========show all record========");       
173             App.getAllRecord(tablename);       
174         } catch (Exception e) {       
175             e.printStackTrace();       
176         }       
177     }
178 }

结果显示为：ui

table already exists
insert recored zkb to table scores ok.
insert recored zkb to table scores ok.
insert recored zkb to table scores ok.
insert recored zkb to table scores ok.
insert recored baoniu to table scores ok.
insert recored baoniu to table scores ok.
===========get one record========
行健: zkb列簇: course 列: 值: 90时间戳: 1501034629784
行健: zkb列簇: course 列: art 值: 87时间戳: 1501034629794
行健: zkb列簇: course 列: math 值: 97时间戳: 1501034629787
行健: zkb列簇: grade 列: 值: 5时间戳: 1501034629768
===========show all record========
baoniu course:math 89
baoniu grade: 4
zkb course: 90
zkb course:art 87
zkb course:math 97
zkb grade: 5
===========del one record========
del recored baoniu ok.
zkb course: 90
zkb course:art 87
zkb course:math 97
zkb grade: 5
===========show all record========
zkb course: 90
zkb course:art 87
zkb course:math 97
zkb grade: 5spa