Reapply "feat: 添加 TableExist 类用于检查 HBase 表是否存在"

This reverts commit ac8bc7357d.

src/main/java/EmployeeDAO.java

@@ -1,40 +0,0 @@
-// 新建员工数据访问类
-import org.apache.hadoop.hbase.client.*;
-import org.apache.hadoop.hbase.util.Bytes;
-import java.io.*;
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-import java.util.*;
-
-public class EmployeeDAO {
-    private static final String[] CF_ARRAY = {"empnum", "info", "salary", "performance", "training"};
-
-    public void insertData(String filePath) throws IOException, NoSuchAlgorithmException {
-        try(Table table = HBaseConnectionManager.getConnection().getTable(TableName.valueOf("emp1520"))) {
-            BufferedReader br = new BufferedReader(new FileReader(filePath));
-            String line;
-            while ((line = br.readLine()) != null) {
-                String[] emp = line.split(",");
-                if (emp.length < 12) continue;
-                
-                String rowKey = generateRowKey(emp[0]);
-                Put put = new Put(Bytes.toBytes(rowKey));
-                table.put(put);
-            }
-            br.close();
-        }
-        System.out.println("Data inserted successfully!");
-    }
-
-    private String generateRowKey(String empno) throws NoSuchAlgorithmException {
-    }
-
-    public void queryById() throws IOException {
-    }
-
-    public void queryByPerformance() throws IOException {
-    }
-
-    public void queryRecentPromotion() throws IOException {
-    }
-}

src/main/java/HBaseConnectionManager.java

@@ -1,41 +0,0 @@
-// 新建连接管理类
-import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.hbase.HBaseConfiguration;
-import org.apache.hadoop.hbase.client.Connection;
-import org.apache.hadoop.hbase.client.ConnectionFactory;
-import org.apache.hadoop.hbase.client.Admin;
-
-public class HBaseConnectionManager {
-    private static Configuration configuration;
-    private static Connection connection;
-    private static Admin admin;
-
-    public static void init() {
-        configuration = HBaseConfiguration.create();
-        try {
-            connection = ConnectionFactory.createConnection(configuration);
-            admin = connection.getAdmin();
-            System.out.println("Connected to HBase Successfully!");
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    public static void close() {
-        try {
-            if (admin != null) admin.close();
-            if (connection != null) connection.close();
-            System.out.println("HBase Connection Closed.");
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
-    }
-
-    public static Admin getAdmin() {
-        return admin;
-    }
-
-    public static Connection getConnection() {
-        return connection;
-    }
-}

src/main/java/HBaseEmpManager.java

@@ -8,24 +8,206 @@ import java.security.NoSuchAlgorithmException;
 import java.util.*;
 
 public class HBaseEmpManager {
-    public static void main(String[] args) {
+    private static Configuration configuration;
+    private static Connection connection;
+    private static Admin admin;
+
+    private static final String TABLE_NAME = "emp1520";
+    private static final String CF_EMPNUM = "empnum";
+    private static final String CF_INFO = "info";
+    private static final String CF_SALARY = "salary";
+    private static final String CF_PERFORMANCE = "performance";
+    private static final String CF_TRAINING = "training";
+
+    public static void main(String[] args) throws IOException, NoSuchAlgorithmException {
+        init(); // 初始化 HBase 连接
+        createTable(); // 创建表
+        insertData("emp.txt"); // 读取 emp.txt 插入数据
+        queryById(); // 查询 ID > 7500 的员工
+        queryByPerformance(); // 查询绩效评分 > 4 且入职时间 < 2022 年的员工
+        queryRecentPromotion(); // 查找最近晋升的员工
+        countTrainingParticipants(); // 统计培训课程的参与人数
+        close(); // 关闭连接
+    }
+
+    // 初始化 HBase 连接
+    private static void init() {
+        configuration = HBaseConfiguration.create();
         try {
-            HBaseConnectionManager.init();
-            HBaseTableManager.createTable(HBaseConnectionManager.getAdmin());
-            
-            EmployeeDAO employeeDAO = new EmployeeDAO();
-            employeeDAO.insertData("emp.txt");
-            employeeDAO.queryById();
-            employeeDAO.queryByPerformance();
-            employeeDAO.queryRecentPromotion();
-            
-            TrainingDAO trainingDAO = new TrainingDAO();
-            trainingDAO.countTrainingParticipants();
-            
-        } catch (Exception e) {
+            connection = ConnectionFactory.createConnection(configuration);
+            admin = connection.getAdmin();
+            System.out.println("Connected to HBase Successfully!");
+        } catch (IOException e) {
             e.printStackTrace();
-        } finally {
-            HBaseConnectionManager.close();
         }
     }
+
+    // 关闭 HBase 连接
+    private static void close() {
+        try {
+            if (admin != null) {
+                admin.close();
+            }
+            if (connection != null) {
+                connection.close();
+            }
+            System.out.println("HBase Connection Closed.");
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    // 创建 HBase 表
+    private static void createTable() throws IOException {
+        TableName tableName = TableName.valueOf(TABLE_NAME);
+        // 检查表格是否存在
+        if (admin.tableExists(tableName)) {
+            System.out.println("表 " + TABLE_NAME + " 已经存在，准备禁用并删除...");
+
+            // 禁用表格
+            admin.disableTable(tableName);
+            System.out.println("表 " + TABLE_NAME + " 已禁用。");
+
+            // 删除表格
+            admin.deleteTable(tableName);
+            System.out.println("表 " + TABLE_NAME + " 已删除。");
+        }
+
+        HTableDescriptor tableDescriptor = new HTableDescriptor(tableName);
+        tableDescriptor.addFamily(new HColumnDescriptor(CF_EMPNUM));
+        tableDescriptor.addFamily(new HColumnDescriptor(CF_INFO));
+        tableDescriptor.addFamily(new HColumnDescriptor(CF_SALARY));
+        tableDescriptor.addFamily(new HColumnDescriptor(CF_PERFORMANCE));
+        tableDescriptor.addFamily(new HColumnDescriptor(CF_TRAINING));
+
+        admin.createTable(tableDescriptor);
+        System.out.println("Table emp1520 created successfully.");
+    }
+
+    // 读取并插入数据
+    private static void insertData(String filePath) throws IOException, NoSuchAlgorithmException {
+        Table table = connection.getTable(TableName.valueOf(TABLE_NAME));
+        BufferedReader br = new BufferedReader(new FileReader(filePath));
+        String line;
+
+        while ((line = br.readLine()) != null) {
+            String[] emp = line.split(",");
+
+            if (emp.length < 12) continue; // 确保数据完整
+
+            String rowKey = generateRowKey(emp[0]); // 使用哈希前缀
+
+            Put put = new Put(Bytes.toBytes(rowKey));
+            put.addColumn(Bytes.toBytes(CF_EMPNUM), Bytes.toBytes("empno"), Bytes.toBytes(emp[0]));
+            put.addColumn(Bytes.toBytes(CF_INFO), Bytes.toBytes("ename"), Bytes.toBytes(emp[1]));
+            put.addColumn(Bytes.toBytes(CF_INFO), Bytes.toBytes("job"), Bytes.toBytes(emp[2]));
+            put.addColumn(Bytes.toBytes(CF_INFO), Bytes.toBytes("mgr"), Bytes.toBytes(emp[3]));
+            put.addColumn(Bytes.toBytes(CF_INFO), Bytes.toBytes("hiredate"), Bytes.toBytes(emp[4]));
+            put.addColumn(Bytes.toBytes(CF_SALARY), Bytes.toBytes("sal"), Bytes.toBytes(emp[5]));
+            put.addColumn(Bytes.toBytes(CF_SALARY), Bytes.toBytes("credit"), Bytes.toBytes(emp[6]));
+            put.addColumn(Bytes.toBytes(CF_INFO), Bytes.toBytes("deptno"), Bytes.toBytes(emp[7]));
+            put.addColumn(Bytes.toBytes(CF_INFO), Bytes.toBytes("work_hours"), Bytes.toBytes(emp[8]));
+            put.addColumn(Bytes.toBytes(CF_PERFORMANCE), Bytes.toBytes("performance_rating"), Bytes.toBytes(emp[9]));
+            put.addColumn(Bytes.toBytes(CF_PERFORMANCE), Bytes.toBytes("promotion_date"), Bytes.toBytes(emp[10]));
+            put.addColumn(Bytes.toBytes(CF_TRAINING), Bytes.toBytes("training_courses"), Bytes.toBytes(emp[11]));
+
+            table.put(put);
+        }
+
+        br.close();
+        table.close();
+        System.out.println("Data inserted successfully!");
+    }
+
+    // 生成 RowKey，避免 Region 热点
+    private static String generateRowKey(String empno) throws NoSuchAlgorithmException {
+        String prefix = empno.substring(0, 3);
+        MessageDigest md5 = MessageDigest.getInstance("MD5");
+        byte[] digest = md5.digest(prefix.getBytes());
+        StringBuilder hexString = new StringBuilder();
+        for (byte b : digest) {
+            hexString.append(String.format("%02x", b));
+        }
+        return hexString.substring(0, 4) + empno;
+    }
+
+    // 查询 ID > 7500 的员工
+    private static void queryById() throws IOException {
+        Table table = connection.getTable(TableName.valueOf(TABLE_NAME));
+        Scan scan = new Scan();
+        scan.addColumn(Bytes.toBytes(CF_EMPNUM), Bytes.toBytes("empno"));
+
+        ResultScanner scanner = table.getScanner(scan);
+        for (Result result : scanner) {
+            String empno = Bytes.toString(result.getValue(Bytes.toBytes(CF_EMPNUM), Bytes.toBytes("empno")));
+            if (empno != null && Integer.parseInt(empno) > 7500) {
+                System.out.println("ID > 7500 Employee: " + empno);
+            }
+        }
+        table.close();
+    }
+
+    // 查询绩效评分 > 4 且入职时间 < 2022 年
+    private static void queryByPerformance() throws IOException {
+        Table table = connection.getTable(TableName.valueOf(TABLE_NAME));
+        Scan scan = new Scan();
+        scan.addColumn(Bytes.toBytes(CF_INFO), Bytes.toBytes("hiredate"));
+        scan.addColumn(Bytes.toBytes(CF_PERFORMANCE), Bytes.toBytes("performance_rating"));
+
+        ResultScanner scanner = table.getScanner(scan);
+        for (Result result : scanner) {
+            String hiredate = Bytes.toString(result.getValue(Bytes.toBytes(CF_INFO), Bytes.toBytes("hiredate")));
+            String rating = Bytes.toString(result.getValue(Bytes.toBytes(CF_PERFORMANCE), Bytes.toBytes("performance_rating")));
+
+            if (hiredate.compareTo("2022-01-01") < 0 && Integer.parseInt(rating) > 4) {
+                System.out.println("Qualified Employee: Hire Date " + hiredate + ", Rating " + rating);
+            }
+        }
+        table.close();
+    }
+
+    // 查找最近晋升的员工
+    private static void queryRecentPromotion() throws IOException {
+        Table table = connection.getTable(TableName.valueOf(TABLE_NAME));
+        Scan scan = new Scan();
+        scan.addColumn(Bytes.toBytes(CF_PERFORMANCE), Bytes.toBytes("promotion_date"));
+
+        ResultScanner scanner = table.getScanner(scan);
+        String latestDate = "";
+        String latestEmp = "";
+
+        for (Result result : scanner) {
+            String promotionDate = Bytes.toString(result.getValue(Bytes.toBytes(CF_PERFORMANCE), Bytes.toBytes("promotion_date")));
+            if (promotionDate != null && promotionDate.compareTo(latestDate) > 0) {
+                latestDate = promotionDate;
+                latestEmp = Bytes.toString(result.getRow());
+            }
+        }
+        System.out.println("Most Recently Promoted Employee: " + latestEmp + ", Promotion Date: " + latestDate);
+        table.close();
+    }
+
+    // 统计培训课程的参与人数
+    private static void countTrainingParticipants() throws IOException {
+        Table table = connection.getTable(TableName.valueOf(TABLE_NAME));
+        Scan scan = new Scan();
+        scan.addColumn(Bytes.toBytes(CF_TRAINING), Bytes.toBytes("training_courses"));
+
+        ResultScanner scanner = table.getScanner(scan);
+        Map<String, Integer> countMap = new HashMap<>();
+
+        for (Result result : scanner) {
+            String courses = Bytes.toString(result.getValue(Bytes.toBytes(CF_TRAINING), Bytes.toBytes("training_courses")));
+            for (String course : courses.split(", ")) {
+                countMap.put(course, countMap.getOrDefault(course, 0) + 1);
+            }
+        }
+
+        System.out.println("培训课程统计:");
+        for (Map.Entry<String, Integer> entry : countMap.entrySet()) {
+            System.out.println(entry.getKey() + ": " + entry.getValue() + " 人");
+        }
+
+        table.close();
+    }
 }

src/main/java/HBaseTableManager.java

@@ -1,26 +0,0 @@
-// 新建表管理类
-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;
-
-public class HBaseTableManager {
-    private static final String TABLE_NAME = "emp1520";
-    private static final String[] CF_ARRAY = {"empnum", "info", "salary", "performance", "training"};
-
-    public static void createTable(Admin admin) throws IOException {
-        TableName tableName = TableName.valueOf(TABLE_NAME);
-        if (admin.tableExists(tableName)) {
-            admin.disableTable(tableName);
-            admin.deleteTable(tableName);
-            System.out.println("Existing table removed");
-        }
-
-        HTableDescriptor tableDescriptor = new HTableDescriptor(tableName);
-        for (String cf : CF_ARRAY) {
-            tableDescriptor.addFamily(new HColumnDescriptor(cf));
-        }
-        admin.createTable(tableDescriptor);
-        System.out.println("Table created successfully");
-    }
-}

src/main/java/TableExist.java

@@ -0,0 +1,52 @@
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.*;
+import org.apache.hadoop.hbase.client.*;
+import java.io.IOException;
+import java.util.Scanner;
+public class TableExist{
+    public static Configuration configuration;
+    public static Connection connection;
+    public static Admin admin;
+    public static void main(String[] args)throws IOException{
+
+        Scanner sc = new Scanner(System.in);
+        System.out.print("tableName:");
+        String tableName = sc.next();
+        init();
+
+        TableName tn = TableName.valueOf(tableName);
+        if(admin.tableExists(tn)) {
+            System.out.println("table " + tableName + " does exist!");
+        } else {
+            System.out.println("table " + tableName + " don't exist!");
+        }
+        close();
+    }
+    //建立连接
+    public static void init(){
+        //根据 hbase-site.xml文件初始化Configuration 对象
+        configuration  = HBaseConfiguration.create();
+        try{
+            //根据 Configuration对象初始化Connection 对象
+            connection = ConnectionFactory.createConnection(configuration);
+            //获取Admin 对象实例
+            admin = connection.getAdmin();
+        }catch (IOException e){
+            e.printStackTrace();
+        }
+        System.out.println("Connect to HBase successfully!");
+    }
+    //关闭连接
+    public static void close(){
+        try{
+            if(admin != null){
+                admin.close();
+            }
+            if(null != connection){
+                connection.close();
+            }
+        }catch (IOException e){
+            e.printStackTrace();
+        }
+    }
+}

src/main/java/TrainingDAO.java

@@ -1,28 +0,0 @@
-// 新建培训统计类
-import org.apache.hadoop.hbase.client.*;
-import org.apache.hadoop.hbase.util.Bytes;
-import java.util.*;
-
-public class TrainingDAO {
-    public void countTrainingParticipants() throws IOException {
-        try(Table table = HBaseConnectionManager.getConnection().getTable(TableName.valueOf("emp1520"))) {
-            Scan scan = new Scan();
-            scan.addColumn(Bytes.toBytes("training"), Bytes.toBytes("training_courses"));
-            
-            ResultScanner scanner = table.getScanner(scan);
-            Map<String, Integer> countMap = new HashMap<>();
-            
-            for (Result result : scanner) {
-                String courses = Bytes.toString(result.getValue(Bytes.toBytes("training"), Bytes.toBytes("training_courses")));
-                for (String course : courses.split(", ")) {
-                    countMap.put(course, countMap.getOrDefault(course, 0) + 1);
-                }
-            }
-            
-            System.out.println("培训课程统计:");
-            for (Map.Entry<String, Integer> entry : countMap.entrySet()) {
-                System.out.println(entry.getKey() + ": " + entry.getValue() + " 人");
-            }
-        }
-    }
-}