feat(spark-lesson): spark实验五部分内容，添加新的 Spark RDD 操作示例

- 新增了 6 个 Spark RDD 操作示例程序
- 包括求平均分、低于 60 分的成绩、最低2 个成绩、二次排序等操作
- 示例程序展示了 Spark RDD 的基本操作和常用算子的使用方法

hbase-lesson/src/main/java/date_20250411/task_DML_select.java

@@ -11,8 +11,9 @@ import org.apache.hadoop.hbase.util.Bytes;
 
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Iterator;
+import java.util.Arrays;
+
 
 public class task_DML_select {
     public static void main(String[] args) throws Exception {
@@ -27,7 +28,11 @@ public class task_DML_select {
         Table table = conn.getTable(TableName.valueOf("ideaPro_space:students"));
 
 
-        scanRows(table);
+//        scanRows(table);
+
+//        getKeyValue(table,"000000");
+
+        getFamily(table);
 
         // 关闭连接
         table.close();
@@ -40,20 +45,20 @@ public class task_DML_select {
      *
      * @param table
      */
-    public static void getKeyValue(Table table) throws IOException {
+    public static void getKeyValue(Table table,String rowKey) throws IOException {
 
 
-        String rowKey = "000010";
+//        String rowKey = "000010";
 
         Get getParam = new Get(Bytes.toBytes(rowKey));
-        getParam.addColumn(Bytes.toBytes("base_info"), Bytes.toBytes("age"));
+        getParam.addColumn(Bytes.toBytes("extra_info"), Bytes.toBytes("salary"));
 
 
         Result result = table.get(getParam);
 
-        byte[] value = result.getValue(Bytes.toBytes("base_info"), Bytes.toBytes("age"));
+        byte[] value = result.getValue(Bytes.toBytes("extra_info"), Bytes.toBytes("salary"));
 
-        int age = Bytes.toInt(value);
+        String age = Bytes.toString(value);
 
         System.out.println(age);
 
@@ -70,10 +75,10 @@ public class task_DML_select {
      */
     public static void getFamily(Table table) throws IOException {
 
-        String rowKey = "000010";
+        String rowKey = "000000";
 
         Get getParam = new Get(Bytes.toBytes(rowKey));
-        getParam.addFamily(Bytes.toBytes("base_info"));
+        getParam.addFamily(Bytes.toBytes("extra_info"));
 
         Result result = table.get(getParam);
         CellScanner cellScanner = result.cellScanner();