实验3 熟悉常用的HBase操作
一、实验目的理解HBase在Hadoop体系结构中的角色;熟练使用HBase操作常用的shell命令;熟悉HBase操作常用的Java API;二、实验平台操作系统:Linux;Hadoop版本:3.1.3;HBase版本:2.2.2;JDK版本:1.8;Java IDE:Eclipse。三、实验步骤(一)编程实现以下指定功能,并利用Hadoop提供的HBase Shell命令完成相同任务;列出H
一、实验目的
- 理解HBase在Hadoop体系结构中的角色;
- 熟练使用HBase操作常用的shell命令;
- 熟悉HBase操作常用的Java API;
二、实验平台
- 操作系统:Linux;
- Hadoop版本:3.1.3;
- HBase版本:2.2.2;
- JDK版本:1.8;
- Java IDE:Eclipse。
三、实验步骤
(一)编程实现以下指定功能,并利用Hadoop提供的HBase Shell命令完成相同任务;
- 列出HBase所有的表的相关新信息,例如表名;
//列出HBase所有的表的相关信息,例如表名、创建时间等 public static void listTables() throws IOException { init();//建立连接 List<TableDescriptor> tableDescriptors = admin.listTableDescriptors(); for (TableDescriptor tableDescriptor : tableDescriptors) { TableName tableName = tableDescriptor.getTableName(); System.out.println("Table:"+tableName); } close();//关闭连接 }
- 在终端打印出指定的表的所有记录数据
//在终端打印出指定的表的所有记录数据 public static void getData(String tableName) throws IOException { init(); Table table = connection.getTable(TableName.valueOf(tableName)); Scan scan = new Scan(); ResultScanner scanner = table.getScanner(scan);//获取行的遍历器 for (Result result:scanner) { printRecoder(result); } close(); } //打印一条记录的详情 private static void printRecoder(Result result) { // TODO Auto-generated method stub for(Cell cell:result.rawCells()) { String str1 = Bytes.toString(cell.getRowArray(),cell.getRowOffset(),cell.getRowLength()); System.out.println("行键:"+ str1); String str2 = Bytes.toString(cell.getFamilyArray(),cell.getFamilyOffset(),cell.getFamilyLength()); System.out.println("列簇:" + str2); String str3 = Bytes.toString(cell.getQualifierArray(),cell.getQualifierOffset(),cell.getQualifierLength()); System.out.println("列:" + str3); String str4 = Bytes.toString(cell.getValueArray(),cell.getValueOffset(),cell.getValueLength()); System.out.println("值:" + str4); System.out.println("时间戳:" + cell.getTimestamp()); } }
- 向已经创建好的表添加和删除指定的列簇或列
//向已经创建好的表添加和删除指定的列簇或列 //向表添加数据 public static void insterRow(String tableName,String rowKey,String colFamily,String col,String val) throws IOException { init(); Table table = connection.getTable(TableName.valueOf(tableName)); Put put = new Put(rowKey.getBytes()); put.addColumn(colFamily.getBytes(), col.getBytes(), val.getBytes()); table.put(put); table.close(); close(); } //删除数据 public static void deleRow(String tableName,String rowKey,String colFamily,String col) throws IOException { init(); Table table = connection.getTable(TableName.valueOf(tableName)); Delete delete = new Delete(rowKey.getBytes()); //删除指定列簇 delete.addFamily(Bytes.toBytes(colFamily)); //删除指定列 delete.addColumn(Bytes.toBytes(colFamily),Bytes.toBytes(col)); table.delete(delete); table.close(); close(); }
- 清空指定的表的所有记录数据
//清空指定的表的所有记录数据 public static void clearRows(String tableName) throws IOException { init(); TableName tablename = TableName.valueOf(tableName); admin.disableTable(tablename); System.out.println("disable...delete..."); admin.deleteTable(tablename); System.out.println("delete...over...create"); TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tablename); ColumnFamilyDescriptor colFamilyDes=ColumnFamilyDescriptorBuilder.newBuilder(" ".getBytes()).build(); tableDescriptor.setColumnFamily(colFamilyDes).build(); admin.createTable(tableDescriptor.build()); close(); }
- 统计表的行数
//统计表的行数 public static void countRows(String tableName) throws IOException { init(); Table table = connection.getTable(TableName.valueOf(tableName)); Scan scan = new Scan(); ResultScanner scanner = table.getScanner(scan); int num = 0; for (Result result = scanner.next();result!=null;result=scanner.next()) { num++; } System.out.println("行数:" + num); scanner.close(); close(); }
以上的全部代码:
import java.io.IOException; import java.util.List; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.hbase.client.*; import org.apache.hadoop.hbase.util.Bytes; import org.apache.hadoop.hbase.*; public class Test { public static Configuration configuration; public static Connection connection; public static Admin admin; //建立连接 public static void init() { configuration = HBaseConfiguration.create(); configuration.set("hbase.rootdir", "hdfs://localhost:9000/hbase"); try { connection = ConnectionFactory.createConnection(configuration); admin = connection.getAdmin(); } catch (IOException e) { // TODO: handle exception e.printStackTrace(); } } //关闭连接 public static void close() { try { if (admin != null) { admin.close(); } if (null != connection) { connection.close(); } } catch (IOException e) { // TODO: handle exception e.printStackTrace(); } } //列出HBase所有的表的相关信息,例如表名、创建时间等 public static void listTables() throws IOException { init();//建立连接 List<TableDescriptor> tableDescriptors = admin.listTableDescriptors(); for (TableDescriptor tableDescriptor : tableDescriptors) { TableName tableName = tableDescriptor.getTableName(); System.out.println("Table:"+tableName); } close();//关闭连接 } //在终端打印出指定的表的所有记录数据 public static void getData(String tableName) throws IOException { init(); Table table = connection.getTable(TableName.valueOf(tableName)); Scan scan = new Scan(); ResultScanner scanner = table.getScanner(scan);//获取行的遍历器 for (Result result:scanner) { printRecoder(result); } close(); } //打印一条记录的详情 private static void printRecoder(Result result) { // TODO Auto-generated method stub for(Cell cell:result.rawCells()) { String str1 = Bytes.toString(cell.getRowArray(),cell.getRowOffset(),cell.getRowLength()); System.out.println("行键:"+ str1); String str2 = Bytes.toString(cell.getFamilyArray(),cell.getFamilyOffset(),cell.getFamilyLength()); System.out.println("列簇:" + str2); String str3 = Bytes.toString(cell.getQualifierArray(),cell.getQualifierOffset(),cell.getQualifierLength()); System.out.println("列:" + str3); String str4 = Bytes.toString(cell.getValueArray(),cell.getValueOffset(),cell.getValueLength()); System.out.println("值:" + str4); System.out.println("时间戳:" + cell.getTimestamp()); } } //向已经创建好的表添加和删除指定的列簇或列 //向表添加数据 public static void insterRow(String tableName,String rowKey,String colFamily,String col,String val) throws IOException { init(); Table table = connection.getTable(TableName.valueOf(tableName)); Put put = new Put(rowKey.getBytes()); put.addColumn(colFamily.getBytes(), col.getBytes(), val.getBytes()); table.put(put); table.close(); close(); } //删除数据 public static void deleRow(String tableName,String rowKey,String colFamily,String col) throws IOException { init(); Table table = connection.getTable(TableName.valueOf(tableName)); Delete delete = new Delete(rowKey.getBytes()); //删除指定列簇 delete.addFamily(Bytes.toBytes(colFamily)); //删除指定列 delete.addColumn(Bytes.toBytes(colFamily),Bytes.toBytes(col)); table.delete(delete); table.close(); close(); } //清空指定的表的所有记录数据 public static void clearRows(String tableName) throws IOException { init(); TableName tablename = TableName.valueOf(tableName); admin.disableTable(tablename); System.out.println("disable...delete..."); admin.deleteTable(tablename); System.out.println("delete...over...create"); TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tablename); ColumnFamilyDescriptor colFamilyDes=ColumnFamilyDescriptorBuilder.newBuilder(" ".getBytes()).build(); tableDescriptor.setColumnFamily(colFamilyDes).build(); admin.createTable(tableDescriptor.build()); close(); } //统计表的行数 public static void countRows(String tableName) throws IOException { init(); Table table = connection.getTable(TableName.valueOf(tableName)); Scan scan = new Scan(); ResultScanner scanner = table.getScanner(scan); int num = 0; for (Result result = scanner.next();result!=null;result=scanner.next()) { num++; } System.out.println("行数:" + num); scanner.close(); close(); } public static void main(String[] args) throws IOException { // TODO Auto-generated method stub // listTables(); // getData("teacher"); // getData("student"); // deleRow("s1", "lisi", "score", "English"); // clearRows("s1"); // countRows("s2"); insterRow("s2", "xiaohong", "score", "Computer", "60"); } }
(二)HBase数据库操作
1. 现有以下关系型数据库中的表和数据(见表14-3到表14-5),要求将其转换为适合于HBase存储的表并插入数据:
表14-3 学生表(Student)
学号(S_No) | 姓名(S_Name) | 性别(S_Sex) | 年龄(S_Age) |
2015001 | Zhangsan | male | 23 |
2015002 | Mary | female | 22 |
2015003 | Lisi | male | 24 |
表14-4 课程表(Course)
课程号(C_No) | 课程名(C_Name) | 学分(C_Credit) |
123001 | Math | 2.0 |
123002 | Computer Science | 5.0 |
123003 | English | 3. |
表14-5 选课表(SC)
学号(SC_Sno) | 课程号(SC_Cno) | 成绩(SC_Score) |
2015001 | 123001 | 86 |
2015001 | 123003 | 69 |
2015002 | 123002 | 77 |
2015002 | 123003 | 99 |
2015003 | 123001 | 98 |
2015003 | 123002 | 95 |
创建表:
添加数据:
2. 请编程实现以下功能:
(1)createTable(String tableName, String[] fields)
创建表,参数tableName为表的名称,字符串数组fields为存储记录各个字段名称的数组。要求当HBase已经存在名为tableName的表的时候,先删除原有的表,然后再创建新的表。
(2)addRecord(String tableName, String row, String[] fields, String[] values)
向表tableName、行row(用S_Name表示)和字符串数组fields指定的单元格中添加对应的数据values。其中,fields中每个元素如果对应的列族下还有相应的列限定符的话,用“columnFamily:column”表示。例如,同时向“Math”、“Computer Science”、“English”三列添加成绩时,字符串数组fields为{“Score:Math”, ”Score:Computer Science”, ”Score:English”},数组values存储这三门课的成绩。
(3)scanColumn(String tableName, String column)
浏览表tableName某一列的数据,如果某一行记录中该列数据不存在,则返回null。要求当参数column为某一列族名称时,如果底下有若干个列限定符,则要列出每个列限定符代表的列的数据;当参数column为某一列具体名称(例如“Score:Math”)时,只需要列出该列的数据。
(4)modifyData(String tableName, String row, String column)
修改表tableName,行row(可以用学生姓名S_Name表示),列column指定的单元格的数据。
(5)deleteRow(String tableName, String row)
删除表tableName中row指定的行的记录。
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import org.apache.hadoop.hbase.util.Bytes;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class Test2 {
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
//建立连接
public static void init(){
configuration = HBaseConfiguration.create();
configuration.set("hbase.rootdir","hdfs://localhost:9000/hbase");
try{
connection = ConnectionFactory.createConnection(configuration);
admin = connection.getAdmin();
}catch (IOException e){
e.printStackTrace();
}
}
//关闭连接
public static void close(){
try{
if(admin != null){
admin.close();
}
if(null != connection){
connection.close();
}
}catch (IOException e){
e.printStackTrace();
}
}
/*createTable(String tableName, String[] fields)
创建表,参数tableName为表的名称,字符串数组fields为存储记录各个域名称的数组。
要求当HBase已经存在名为tableName的表的时候,先删除原有的表,然后再创建新的表。
*/
public static void createTable(String tableName,String[] fields) throws IOException {
init();
TableName tablename = TableName.valueOf(tableName);
if(admin.tableExists(tablename)){
System.out.println("table is exists!");
admin.disableTable(tablename);
admin.deleteTable(tablename);//删除原来的表
System.out.println("删除成功!");
}
System.out.println("开始创建表...");
List<ColumnFamilyDescriptor> colFamilyList=new ArrayList<>();
TableDescriptorBuilder tableDescriptor = TableDescriptorBuilder.newBuilder(tablename);
for(String str:fields) {
ColumnFamilyDescriptor colFamilyDes=ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(str)).build();
colFamilyList.add(colFamilyDes);
}
TableDescriptor tableDes=tableDescriptor.setColumnFamilies(colFamilyList).build();
admin.createTable(tableDes);
System.out.println(tableName+"创建成功!");
close();
}
/*addRecord(String tableName, String row, String[] fields, String[] values)
向表tableName、行row(用S_Name表示)和字符串数组files指定的单元格中添加对应的数据values。
其中fields中每个元素如果对应的列族下还有相应的列限定符的话,用“columnFamily:column”表示。
例如,同时向“Math”、“Computer Science”、“English”三列添加成绩时,字符串数组
fields为{“Score:Math”,”Score:Computer Science”,”Score:English”},数组values存储这三门课的成绩。
*/
public static void addRecord(String tableName,String row,String[] fields,String[] values) throws IOException {
init();
Table table = connection.getTable(TableName.valueOf(tableName));
System.out.println("准备添加数据...");
for(int i = 0;i != fields.length;i++){
Put put = new Put(row.getBytes());
String[] cols = fields[i].split(":");
put.addColumn(cols[0].getBytes(),cols[1].getBytes(), values[i].getBytes());
System.out.println(i+"put..."+i);
table.put(put);
System.out.println(i+"...ok");
}
table.close();
close();
}
/*(3)scanColumn(String tableName, String column)
浏览表tableName某一列的数据,如果某一行记录中该列数据不存在,则返回null。
要求当参数column为某一列族名称时,如果底下有若干个列限定符,则要列出每个列限定符代表的列的数据;
当参数column为某一列具体名称(例如“Score:Math”)时,只需要列出该列的数据。
*/
public static void scanColumn(String tableName,String column)throws IOException{
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Scan scan = new Scan();
scan.addFamily(Bytes.toBytes(column));
ResultScanner scanner = table.getScanner(scan);
for (Result result = scanner.next(); result != null; result = scanner.next()){
showCell(result);
}
table.close();
close();
}
//格式化输出
public static void showCell(Result result){
Cell[] cells = result.rawCells();
for(Cell cell:cells){
System.out.println("RowName:"+new String(Bytes.toString(cell.getRowArray(),cell.getRowOffset(), cell.getRowLength()))+" ");
System.out.println("Timetamp:"+cell.getTimestamp()+" ");
System.out.println("column Family:"+new String(Bytes.toString(cell.getFamilyArray(),cell.getFamilyOffset(), cell.getFamilyLength()))+" ");
System.out.println("row Name:"+new String(Bytes.toString(cell.getQualifierArray(),cell.getQualifierOffset(), cell.getQualifierLength()))+" ");
System.out.println("value:"+new String(Bytes.toString(cell.getValueArray(),cell.getValueOffset(), cell.getValueLength()))+" ");
}
}
/*modifyData(String tableName, String row, String column)
修改表tableName,行row(可以用学生姓名S_Name表示),列column指定的单元格的数据。*/
public static void modifyData(String tableName,String row,String column,String val)throws IOException{
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Put put = new Put(row.getBytes());
String[] col = column.split(":");
put.addColumn(col[0].getBytes(),col[1].getBytes(),val.getBytes());
table.put(put);
table.close();
close();
}
/*(5)deleteRow(String tableName, String row)
删除表tableName中row指定的行的记录。*/
public static void deleteRow(String tableName,String row)throws IOException{
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Delete delete = new Delete(row.getBytes());
table.delete(delete);
table.close();
close();
}
public static void main(String[] args)throws IOException{
// scanColumn("s1","score");
// String[] fields = {"score"};
// createTable("s1",fields);
String tableName = "s1";
String row = "001";
// String[] fields = {"score:Math", "score:Computer Science", "score:English"};
// String[] values = {"100","80","60"};
// addRecord(tableName,row,fields,values);
// scanColumn(tableName,"score");
// String column = "score:English";
// String val = "70";
// modifyData(tableName,row, column, val);
deleteRow(tableName,row);
}
}
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