24.10.29

实验3
熟悉常用的HBase操作

1.实验目的
（1）理解HBase在Hadoop体系结构中的角色；
（2）熟练使用HBase操作常用的Shell命令；
（3）熟悉HBase操作常用的Java API。
2.实验平台
（1）操作系统：Linux（建议Ubuntu16.04或Ubuntu18.04）；
（2）Hadoop版本：2.7.3；
（3）HBase版本：2.7.3；
（4）JDK版本：1.8；
（5）Java IDE：IDEA。
3. 实验步骤
（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；
list
（2）在终端打印出指定的表的所有记录数据；
scan '表名'

（3）向已经创建好的表添加和删除指定的列族或列；
disable '表名'
alter '表名', NAME => '新列族'
enable '表名'
（4）清空指定的表的所有记录数据；
truncate '表名'

（5）统计表的行数。
count '表名'

和hdfs操作一样，先将虚机上所有库下载下来导入添加为库
（6） package org.example.hbase;

import org.apache.hadoop.hbase.client.;
import org.apache.hadoop.hbase.;
import org.apache.hadoop.hbase.util.Bytes;

import java.io.IOException;

public class HBaseOperations {
private static Connection connection;
private static Admin admin;

static {
    try {
        connection = ConnectionFactory.createConnection(HBaseConfig.getConfig());
        admin = connection.getAdmin();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

// (1) 列出所有表信息
public static void listTables() throws IOException {
    HTableDescriptor[] tableDescriptors = admin.listTables();
    System.out.println("HBase Tables:");
    for (HTableDescriptor table : tableDescriptors) {
        System.out.println(" - " + table.getTableName());
    }
}

// (2) 打印指定表的所有记录
public static void printTable(String tableName) throws IOException {
    Table table = connection.getTable(TableName.valueOf(tableName));
    Scan scan = new Scan();
    ResultScanner scanner = table.getScanner(scan);

    for (Result result : scanner) {
        System.out.println("Row: " + Bytes.toString(result.getRow()));
        for (Cell cell : result.rawCells()) {
            System.out.println(" - Column: " + Bytes.toString(CellUtil.cloneFamily(cell)) + ":" +
                    Bytes.toString(CellUtil.cloneQualifier(cell)) +
                    ", Value: " + Bytes.toString(CellUtil.cloneValue(cell)));
        }
    }
    table.close();
}

// (3) 添加和删除列族
public static void modifyColumnFamily(String tableName, String columnFamily, boolean add) throws IOException {
    TableName table = TableName.valueOf(tableName);
    if (!admin.tableExists(table)) {
        System.out.println("Table does not exist.");
        return;
    }

    if (add) {
        HColumnDescriptor columnDescriptor = new HColumnDescriptor(columnFamily);
        admin.addColumn(table, columnDescriptor);
        System.out.println("Added column family: " + columnFamily);
    } else {

        admin.deleteColumn(table, Bytes.toBytes(columnFamily));
        System.out.println("Deleted column family: " + columnFamily);
    }
}

// (4) 清空表中的所有记录
public static void truncateTable(String tableName) throws IOException {
    TableName table = TableName.valueOf(tableName);
    if (admin.tableExists(table)) {
        admin.disableTable(table);
        admin.truncateTable(table, true);
        System.out.println("Table " + tableName + " truncated.");
    } else {
        System.out.println("Table does not exist.");
    }
}

// (5) 统计表的行数
public static void countRows(String tableName) throws IOException {
    Table table = connection.getTable(TableName.valueOf(tableName));
    Scan scan = new Scan();
    ResultScanner scanner = table.getScanner(scan);

    int rowCount = 0;
    for (Result ignored : scanner) {
        rowCount++;
    }
    System.out.println("Total rows in table " + tableName + ": " + rowCount);
    table.close();
}

// 关闭连接
public static void closeConnection() {
    try {
        if (admin != null) admin.close();
        if (connection != null) connection.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

public static void main(String[] args) {
    try {
        // 测试功能
        String tableName = "shujuku";
        listTables();
        printTable(tableName);
        modifyColumnFamily(tableName, "NewColumnFamily", true);
        modifyColumnFamily(tableName, "NewColumnFamily2", true);
        modifyColumnFamily(tableName, "NewColumnFamily", false);
        truncateTable(tableName);
        countRows(tableName);
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        closeConnection();
    }
}

}

（二）HBase数据库操作

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 3.0

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

package org.example.hbase;

import org.apache.hadoop.hbase.client.;
import org.apache.hadoop.hbase.;
import org.apache.hadoop.hbase.util.Bytes;

import java.io.IOException;

public class HBaseOperations1 {
private static Connection connection;
private static Admin admin;

static {
    try {
        connection = ConnectionFactory.createConnection(HBaseConfig.getConfig());
        admin = connection.getAdmin();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

// 创建表
public static void createTable(String tableName, String[] columnFamilies) throws IOException {
    TableName table = TableName.valueOf(tableName);
    if (admin.tableExists(table)) {
        System.out.println("Table " + tableName + " exists, deleting...");
        admin.disableTable(table);
        admin.deleteTable(table);
    }
    HTableDescriptor tableDescriptor = new HTableDescriptor(table);
    for (String cf : columnFamilies) {
        tableDescriptor.addFamily(new HColumnDescriptor(cf));
    }
    admin.createTable(tableDescriptor);
    System.out.println("Table " + tableName + " created successfully.");
}

// 插入数据
public static void addRecord(String tableName, String rowKey, String columnFamily, String column, String value) throws IOException {
    Table table = connection.getTable(TableName.valueOf(tableName));
    Put put = new Put(Bytes.toBytes(rowKey));
    put.addColumn(Bytes.toBytes(columnFamily), Bytes.toBytes(column), Bytes.toBytes(value));
    table.put(put);
    table.close();
    System.out.println("Inserted record into table " + tableName + ": RowKey=" + rowKey + ", " + columnFamily + ":" + column + "=" + value);
}

// 关闭连接
public static void closeConnection() {
    try {
        if (admin != null) admin.close();
        if (connection != null) connection.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}
public static void main(String[] args) {
    try {
        // 1. 创建学生表
        String studentTable = "Student";
        String[] studentCF = {"info"};
        createTable(studentTable, studentCF);

        // 插入学生表数据
        addRecord(studentTable, "2015001", "info", "name", "Zhangsan");
        addRecord(studentTable, "2015001", "info", "sex", "male");
        addRecord(studentTable, "2015001", "info", "age", "23");

        addRecord(studentTable, "2015002", "info", "name", "Mary");
        addRecord(studentTable, "2015002", "info", "sex", "female");
        addRecord(studentTable, "2015002", "info", "age", "22");

        addRecord(studentTable, "2015003", "info", "name", "Lisi");
        addRecord(studentTable, "2015003", "info", "sex", "male");
        addRecord(studentTable, "2015003", "info", "age", "24");

        // 2. 创建课程表
        String courseTable = "Course";
        String[] courseCF = {"details"};
        createTable(courseTable, courseCF);

        // 插入课程表数据
        addRecord(courseTable, "123001", "details", "name", "Math");
        addRecord(courseTable, "123001", "details", "credit", "2.0");

        addRecord(courseTable, "123002", "details", "name", "Computer Science");
        addRecord(courseTable, "123002", "details", "credit", "5.0");

        addRecord(courseTable, "123003", "details", "name", "English");
        addRecord(courseTable, "123003", "details", "credit", "3.0");

        // 3. 创建选课表
        String scTable = "SC";
        String[] scCF = {"score"};
        createTable(scTable, scCF);

        // 插入选课表数据
        addRecord(scTable, "2015001:123001", "score", "score", "86");
        addRecord(scTable, "2015001:123003", "score", "score", "69");
        addRecord(scTable, "2015002:123002", "score", "score", "77");
        addRecord(scTable, "2015002:123003", "score", "score", "99");
        addRecord(scTable, "2015003:123001", "score", "score", "98");
        addRecord(scTable, "2015003:123002", "score", "score", "95");

    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        closeConnection();
    }
}

}

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。

package org.example.hbase;

import org.apache.hadoop.hbase.client.;
import org.apache.hadoop.hbase.;
import org.apache.hadoop.hbase.util.Bytes;
import org.example.hbase.HBaseConfig;

import java.io.IOException;

public class HBaseOperations2 {
private static Connection connection;
private static Admin admin;

static {
    try {
        connection = ConnectionFactory.createConnection(HBaseConfig.getConfig());
        admin = connection.getAdmin();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

// 创建表
// 创建表
public static void createTable(String tableName, String[] fields) throws IOException {
    TableName table = TableName.valueOf(tableName);

    // 获取 Admin 对象
    Admin admin = connection.getAdmin();

    // 如果表存在，先删除表
    if (admin.tableExists(table)) {
        System.out.println("Table " + tableName + " already exists. Deleting it...");
        admin.disableTable(table);
        admin.deleteTable(table);
        System.out.println("Deleted table " + tableName);
    }

    // 创建表描述符
    HTableDescriptor tableDescriptor = new HTableDescriptor(table);

    // 根据 fields 添加列族
    for (String field : fields) {
        String[] parts = field.split(":");
        String columnFamily = parts[0];
        if (!tableDescriptor.hasFamily(Bytes.toBytes(columnFamily))) {
            tableDescriptor.addFamily(new HColumnDescriptor(columnFamily));
        }
    }

    // 创建表
    admin.createTable(tableDescriptor);
    System.out.println("Table " + tableName + " created successfully.");

    admin.close();
}


// 添加记录
// 添加记录
public static void addRecord(String tableName, String row, String[] fields, String[] values) throws IOException {
    if (fields.length != values.length) {
        throw new IllegalArgumentException("Fields and values arrays must have the same length.");
    }

    Table table = connection.getTable(TableName.valueOf(tableName));
    Put put = new Put(Bytes.toBytes(row));

    for (int i = 0; i < fields.length; i++) {
        String field = fields[i];
        String[] parts = field.split(":");
        if (parts.length != 2) {
            throw new IllegalArgumentException("Invalid field format. Expected 'columnFamily:column', got: " + field);
        }

        String columnFamily = parts[0];
        String column = parts[1];
        put.addColumn(Bytes.toBytes(columnFamily), Bytes.toBytes(column), Bytes.toBytes(values[i]));
    }

    table.put(put);
    table.close();
    System.out.println("Record added to table " + tableName + " with row key: " + row);
}


// 浏览列数据
public static void scanColumn(String tableName, String column) throws IOException {
    Table table = connection.getTable(TableName.valueOf(tableName));
    Scan scan = new Scan();
    ResultScanner scanner = table.getScanner(scan);
    for (Result result : scanner) {
        if (column.contains(":")) {
            String[] parts = column.split(":");
            String columnFamily = parts[0];
            String qualifier = parts[1];
            byte[] value = result.getValue(Bytes.toBytes(columnFamily), Bytes.toBytes(qualifier));
            System.out.println("Row: " + Bytes.toString(result.getRow()) + ", Column: " + column + ", Value: " + Bytes.toString(value));
        } else {
            for (Cell cell : result.rawCells()) {
                if (Bytes.toString(CellUtil.cloneFamily(cell)).equals(column)) {
                    System.out.println("Row: " + Bytes.toString(result.getRow()) + ", Column: " + Bytes.toString(CellUtil.cloneQualifier(cell)) + ", Value: " + Bytes.toString(CellUtil.cloneValue(cell)));
                }
            }
        }
    }
    table.close();
}

// 修改数据
public static void modifyData(String tableName, String row, String column, String newValue) throws IOException {
    Table table = connection.getTable(TableName.valueOf(tableName));
    String[] parts = column.split(":");
    String columnFamily = parts[0];
    String qualifier = parts.length > 1 ? parts[1] : "";
    Put put = new Put(Bytes.toBytes(row));
    put.addColumn(Bytes.toBytes(columnFamily), Bytes.toBytes(qualifier), Bytes.toBytes(newValue));
    table.put(put);
    table.close();
    System.out.println("Data modified in table " + tableName);
}

// 删除行
public static void deleteRow(String tableName, String row) throws IOException {
    Table table = connection.getTable(TableName.valueOf(tableName));
    Delete delete = new Delete(Bytes.toBytes(row));
    table.delete(delete);
    table.close();
    System.out.println("Row " + row + " deleted from table " + tableName);
}

// 关闭连接
public static void closeConnection() {
    try {
        if (admin != null) admin.close();
        if (connection != null) connection.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

public static void main(String[] args) {
    try {
        String tableName = "Students";
        String[] fields = {"Score:Math", "Score:Computer Science", "Score:English"};
        String[] values = {"85", "90", "88"};
        String row = "John";

        // 测试功能
        createTable(tableName, fields);
        addRecord(tableName, row, fields, values);
        scanColumn(tableName, "Score:Math");
        modifyData(tableName, row, "Score:Math", "95");
        scanColumn(tableName, "Score:Math");
        deleteRow(tableName, row);
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        closeConnection();
    }
}

}

posted @ 2024-10-29 20:05 起名字真难_qmz 阅读(12) 评论(0) 收藏举报

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24.10.29

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