[TD-14055]<fix>: adjust the method of obtaining values (#10958)

src/client/src/TSDBJNIConnector.c

@@ -573,8 +573,7 @@ JNIEXPORT jint JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_fetchBlockImp(JNI
     return code;
   }
 
-  TAOS_RES   *tres = (TAOS_RES *)res;
-  TAOS_FIELD *fields = taos_fetch_fields(tres);
+  TAOS_RES *tres = (TAOS_RES *)res;
 
   int32_t numOfFields = taos_num_fields(tres);
   assert(numOfFields > 0);
@@ -596,14 +595,10 @@ JNIEXPORT jint JNICALL Java_com_taosdata_jdbc_TSDBJNIConnector_fetchBlockImp(JNI
   (*env)->CallVoidMethod(env, rowobj, g_blockdataSetNumOfRowsFp, (jint)numOfRows);
   (*env)->CallVoidMethod(env, rowobj, g_blockdataSetNumOfColsFp, (jint)numOfFields);
 
+  int32_t *field = taos_fetch_lengths(tres);
   for (int i = 0; i < numOfFields; i++) {
-    int bytes = fields[i].bytes;
-
-    if (fields[i].type == TSDB_DATA_TYPE_BINARY || fields[i].type == TSDB_DATA_TYPE_NCHAR) {
-      bytes += 2;
-    }
-    (*env)->CallVoidMethod(env, rowobj, g_blockdataSetByteArrayFp, i, bytes * numOfRows,
-                           jniFromNCharToByteArray(env, (char *)row[i], bytes * numOfRows));
+    (*env)->CallVoidMethod(env, rowobj, g_blockdataSetByteArrayFp, i, field[i] * numOfRows,
+                           jniFromNCharToByteArray(env, (char *)row[i], field[i] * numOfRows));
   }
 
   return JNI_SUCCESS;

src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBResultSetBlockData.java

@@ -408,7 +408,8 @@ public class TSDBResultSetBlockData {
 
             case TSDBConstants.TSDB_DATA_TYPE_NCHAR: {
                 ByteBuffer bb = (ByteBuffer) this.colData.get(col);
-                bb.position((fieldSize + BINARY_LENGTH_OFFSET) * this.rowIndex);
+//                bb.position((fieldSize * 4 + 2 + 1) * this.rowIndex);
+                bb.position(bb.capacity() / numOfRows * this.rowIndex);
                 int length = bb.getShort();
                 byte[] dest = new byte[length];
                 bb.get(dest, 0, length);