• hbase数据库操作


    .实验内容与完成情况:(实验具体步骤和实验截图说明)
    (一)编程实现以下指定功能,并用 Hadoop 提供的 HBase Shell 命令完成相同任务:
    (1) 列出 HBase 所有的表的相关信息,例如表名;
    列出所有数据表:
    列出表的结构
    查询表是否存在
    查询表是否可用
    
    
    packagecn.wl.edu.hbase;
    
    import java.io.IOException;
    
    public class ListTables {
        public static Configuration configuration;
        public static Connection connection;
        public static Admin admin;
    
        public static void listTables() throws IOException {
            init();
            HTableDescriptor[] hTableDescriptors = admin.listTables();
            for (HTableDescriptor hTableDescriptor : hTableDescriptors) {
                System.out.println("table name:"
                        + hTableDescriptor.getNameAsString());
    
            }
                   close();
        }
    
        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();
            }
        }
    
        public static void close() {
            try {
                if (admin != null) {
                    admin.close();
                }
                if (connection != null) {
                    connection.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
        public static void main(String[] args) {
            try {
                listTables();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
    }
    
    
    
    
    
    (2)在终端打印出指定的表的所有记录数据;
    
    
    
    
    
    源代码:
    package cn.wl.edu.hbase;
    
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.Cell;
    import org.apache.hadoop.hbase.CellUtil;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.TableName;
    import org.apache.hadoop.hbase.client.*;
    
    import java.io.IOException;
    
    public class ListTableData {
    
        public static Configuration configuration;
        public static Connection connection;
        public static Admin admin;
        
        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);
            for(Result result:scanner){
                printRecoder(result);
            }
    System.out.println(“finish!”);
            close();
            
        }
        
        public static void printRecoder(Result result)throws IOException{
            for(Cell cell:result.rawCells()){
                System.out.println("行键:"+new String(CellUtil.cloneRow(cell)));
                  System.out.print("列簇: " + new String(CellUtil.cloneFamily(cell)));
                    System.out.print(" 列: " + new String(CellUtil.cloneQualifier(cell)));
                    System.out.print(" 值: " + new String(CellUtil.cloneValue(cell)));
                    System.out.println("时间戳: " + cell.getTimestamp());
            }
        }
        
        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();
            }
        }
    
        public static void close() {
            try {
                if (admin != null) {
                    admin.close();
                }
                if (connection != null) {
                    connection.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
        public static void main(String[] args) {
            try {
            getData("person");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
    
    }
    
    
    
    
    (3) 向已经创建好的表添加和删除指定的列族或列;
    添加数据
    
    
    
    源代码:
    package cn.wl.edu.hbase;
    
    import java.io.IOException;
    
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.TableName;
    import org.apache.hadoop.hbase.client.Admin;
    import org.apache.hadoop.hbase.client.Connection;
    import org.apache.hadoop.hbase.client.ConnectionFactory;
    import org.apache.hadoop.hbase.client.Put;
    import org.apache.hadoop.hbase.client.Table;
    
    public class InsertRow {
        public static Configuration configuration;
        public static Connection connection;
        public static Admin admin;
        
        public static void insertRow(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);
           System.out.println("insert finish!");
           table.close();
        }
        
        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();
            }
        }
    
        public static void close() {
            try {
                if (admin != null) {
                    admin.close();
                }
                if (connection != null) {
                    connection.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
        public static void main(String[] args) {
            try {
            insertRow("student","s002","score","math","100");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
    }
    
    
    
    删除数据
    
    
    
    源代码:
    package cn.wl.edu.hbase;
    import java.io.IOException;
    
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.TableName;
    import org.apache.hadoop.hbase.client.*;
    import org.apache.hadoop.hbase.util.Bytes;
    
    public class DeleteRow {
          public static Configuration configuration;
            public static Connection connection;
            public static Admin admin;
    
            public static void deleteRow(String tableName, String rowKey, String colFamily, String col) throws IOException {
                init();
                Table table = connection.getTable(TableName.valueOf(tableName));
                Delete delete = new Delete(rowKey.getBytes());
                delete.addFamily(Bytes.toBytes(colFamily));
                delete.addColumn(Bytes.toBytes(colFamily), Bytes.toBytes(col));
                table.delete(delete);
                System.out.println("delete successful!");
                table.close();
                close();
            }
    
            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();
                }
            }
    
            public static void close() {
                try {
                    if (admin != null) {
                        admin.close();
                    }
                    if (null != connection) {
                        connection.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
    
            public static void main(String[] args) {
                try {
                    deleteRow("student", "s002", "score", "math");
                } catch (IOException e) {
                    e.printStackTrace();
                }
    
            }
    
    }
    
    
    
    (3)清空指定的表的所有记录数据;
    
    
    
    
    
    源代码:
    package cn.wl.edu.hbase;
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.TableName;
    import org.apache.hadoop.hbase.client.Admin;
    import org.apache.hadoop.hbase.client.Connection;
    import org.apache.hadoop.hbase.client.ConnectionFactory;
    
    import java.io.IOException;
    public class TruncateTable {
         public static Configuration configuration;
            public static Connection connection;
            public static Admin admin;
    
            public static void clearRows(String tableName) throws IOException {
                init();
                TableName tablename = TableName.valueOf(tableName);
                admin.disableTable(tablename);
                admin.truncateTable(tablename, false);
                System.out.println("delete table successful!");
                close();
            }
    
            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();
                }
            }
    
            public static void close() {
                try {
                    if (admin != null) {
                        admin.close();
                    }
                    if (null != connection) {
                        connection.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
    
            public static void main(String[] args) {
                try {
                    clearRows("student");
                } catch (IOException e) {
                    e.printStackTrace();
                }
    
            }
    }
    
    (5) 统计表的行数。
    
    
    
    
    
    源程序:
    package cn.wl.edu.hbase;
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.TableName;
    import org.apache.hadoop.hbase.client.*;
    
    import java.io.IOException;
    public class CountTable {
         public static Configuration configuration;
            public static Connection connection;
            public static Admin admin;
    
            public static void countTable(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 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();
                }
            }
    
            public static void close() {
                try {
                    if (admin != null) {
                        admin.close();
                    }
                    if (null != connection) {
                        connection.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
    
            public static void main(String[] args) {
                try {
                    countTable("student");
                } catch (IOException e) {
                    e.printStackTrace();
                }
    
            }
    }
    
    
    
    
    (二) HBase 数据库操作
    1. 现有以下关系型数据库中的表和数据,要求将其转换为适合于 HBase 存储的表并插入数据:
    
    学生表(Student)
    学号(S_No)     姓名(S_Name)     性别(S_Sex)     年龄(S_Age)
    2015001     Zhangsan     male     23
    2015003     Mary     female     22
    2015003     Lisi     male     24
    
    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     3.0
    
    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
    
    
    
    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。
    package cn.wl.edu.hbase;
    
    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.TableName;
    import org.apache.hadoop.hbase.client.Admin;
    import org.apache.hadoop.hbase.client.Connection;
    import org.apache.hadoop.hbase.client.ConnectionFactory;
    
    import java.io.IOException;
    
    public class CreateTable {
        public static Configuration configuration;
        public static Connection connection;
        public static Admin admin;
    
        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!");
            }
            HTableDescriptor hTableDescriptor = new HTableDescriptor(tablename);
            for (String str : fields) {
                HColumnDescriptor hColumnDescriptor = new HColumnDescriptor(str);
                hTableDescriptor.addFamily(hColumnDescriptor);
            }
            admin.createTable(hTableDescriptor);
            close();
        }
    
        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();
            }
        }
    
        public static void close() {
            try {
                if (admin != null) {
                    admin.close();
                }
                if (null != connection) {
                    connection.close();
                }
    
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
        public static void main(String[] args) {
            String[] fields = { "Score" };
            try {
                createTable("person", fields);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
    }
    
    
    (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。
    源代码:
    package cn.wl.edu.hbase;
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.TableName;
    import org.apache.hadoop.hbase.client.*;
    
    import java.io.IOException;
    
    public class addRecord {
        public static Configuration configuration;
        public static Connection connection;
        public static Admin admin;
    
        public static void addRecord(String tableName, String row, String[] fields, String[] values) throws IOException {
            init();
            Table table = connection.getTable(TableName.valueOf(tableName));
            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());
                table.put(put);
            }
            table.close();
            close();
        }
    
        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();
            }
        }
    
        public static void close() {
            try {
                if (admin != null) {
                    admin.close();
                }
                if (null != connection) {
                    connection.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
        public static void main(String[] args) {
            String[] fields = {"Score:Math", "Score:Computer Science", "Score:English"};
            String[] values = {"99", "80", "100"};
            try {
                addRecord("person", "Score", fields, values);
            } catch (IOException e) {
                e.printStackTrace();
            }
        System.out.println("finish!");
    
        }
    }
    
    
    
    (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。
    源代码:
    package cn.wl.edu.hbase;
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.Cell;
    import org.apache.hadoop.hbase.CellUtil;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.TableName;
    import org.apache.hadoop.hbase.client.*;
    import org.apache.hadoop.hbase.util.Bytes;
    
    import java.io.IOException;
    public class ScanColumn {
         public static Configuration configuration;
            public static Connection connection;
            public static Admin admin;
    
            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);
                }
               System.out.println("finish!");
                table.close();
                close();
            }
    
            public static void showCell(Result result) {
                Cell[] cells = result.rawCells();
                for (Cell cell : cells) {
                    System.out.println("RowName:" + new String(CellUtil.cloneRow(cell)) + " ");
                    System.out.println("Timetamp:" + cell.getTimestamp() + " ");
                    System.out.println("column Family:" + new String(CellUtil.cloneFamily(cell)) + " ");
                    System.out.println("row Name:" + new String(CellUtil.cloneQualifier(cell)) + " ");
                    System.out.println("value:" + new String(CellUtil.cloneValue(cell)) + " ");
                }
            }
    
            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();
                }
            }
    
            public static void main(String[] args) {
                try {
                    scanColumn("person", "Score");
                } catch (IOException e) {
                    e.printStackTrace();
                }
    
            }
    }
    
    
    
    
    
    
    
    
    (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。
    源代码:
    package cn.wl.edu.hbase;
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.Cell;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.TableName;
    import org.apache.hadoop.hbase.client.*;
    
    import java.io.IOException;
    public class ModifyData {
        public static long ts;
        public static Configuration configuration;
        public static Connection connection;
        public static Admin admin;
    
        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());
            Scan scan = new Scan();
            ResultScanner resultScanner = table.getScanner(scan);
            for (Result r : resultScanner) {
                for (Cell cell : r.getColumnCells(row.getBytes(), column.getBytes())) {
                    ts = cell.getTimestamp();
                }
            }
            put.addColumn(row.getBytes(), column.getBytes(), ts, val.getBytes());
            table.put(put);
            System.out.println("modify successful!");
            table.close();
            close();
        }
    
        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();
            }
        }
    
        public static void close() {
            try {
                if (admin != null) {
                    admin.close();
                }
                if (null != connection) {
                    connection.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    
        public static void main(String[] args) {
            try {
                modifyData("person", "Score", "Math", "100");
            } catch (IOException e) {
                e.printStackTrace();
            }
    
        }
    }
    
    
    
    (5) deleteRow(String tableName, String row)
    删除表 tableName 中 row 指定的行的记录。 
    源代码:
    package cn.wl.edu.hbase;
    import java.io.IOException;
    
    import org.apache.hadoop.conf.Configuration;
    import org.apache.hadoop.hbase.HBaseConfiguration;
    import org.apache.hadoop.hbase.TableName;
    import org.apache.hadoop.hbase.client.*;
    import org.apache.hadoop.hbase.util.Bytes;
    
    public class DeleteRow {
          public static Configuration configuration;
            public static Connection connection;
            public static Admin admin;
    
            public static void deleteRow(String tableName, String rowKey, String colFamily, String col) throws IOException {
                init();
                Table table = connection.getTable(TableName.valueOf(tableName));
                Delete delete = new Delete(rowKey.getBytes());
                delete.addFamily(Bytes.toBytes(colFamily));
                delete.addColumn(Bytes.toBytes(colFamily), Bytes.toBytes(col));
                table.delete(delete);
                System.out.println("delete successful!");
                table.close();
                close();
            }
    
            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();
                }
            }
    
            public static void close() {
                try {
                    if (admin != null) {
                        admin.close();
                    }
                    if (null != connection) {
                        connection.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
    
            public static void main(String[] args) {
                try {
                    deleteRow("student", "s002", "score", "math");
                } catch (IOException e) {
                    e.printStackTrace();
                }
    
            }
    
    }
    
    
    
    2.实验中出现问题:(说明和截图)
    Eclipse运行大多数程序,运行时间特别长,既不报错也不显示结果。
    
    3.解决方案:(列出遇到的问题和解决办法,列出没有解决的问题): 
    再次对照查看hbase的安装配置教程,发现自己少了一个步骤。
     在hbase-env.sh文件中添加了这些路径之后就好了。
    
    本文版权归作者和博客园共有,欢迎转载,但未经作者同意必须保留此段声明,且在文章页面明显位置给出原文连接,否则保留追究法律责任的权利.
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  • 原文地址:https://www.cnblogs.com/wl2017/p/10294242.html
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