enh: stmt insert demo

docs/examples/java/src/main/java/com/taos/example/StmtInsertExample.java

@@ -6,39 +6,32 @@ import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;
 import java.sql.Statement;
+import java.text.SimpleDateFormat;
 import java.time.LocalDateTime;
 import java.time.ZoneOffset;
 import java.time.format.DateTimeFormatter;
 import java.util.ArrayList;
-import java.util.Arrays;
+import java.util.Comparator;
 import java.util.List;
+import java.util.Random;
+import java.util.stream.Collectors;
 
 public class StmtInsertExample {
-    private static ArrayList<Long> tsToLongArray(String ts) {
-        ArrayList<Long> result = new ArrayList<>();
-        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
-        LocalDateTime localDateTime = LocalDateTime.parse(ts, formatter);
-        result.add(localDateTime.toInstant(ZoneOffset.of("+8")).toEpochMilli());
-        return result;
-    }
-
-    private static <T> ArrayList<T> toArray(T v) {
-        ArrayList<T> result = new ArrayList<>();
-        result.add(v);
-        return result;
-    }
+    private static String datePattern = "yyyy-MM-dd HH:mm:ss.SSS";
+    private static DateTimeFormatter formatter = DateTimeFormatter.ofPattern(datePattern);
 
-    private static List<String> getRawData() {
-        return Arrays.asList(
-                "d1001,2018-10-03 14:38:05.000,10.30000,219,0.31000,California.SanFrancisco,2",
-                "d1001,2018-10-03 14:38:15.000,12.60000,218,0.33000,California.SanFrancisco,2",
-                "d1001,2018-10-03 14:38:16.800,12.30000,221,0.31000,California.SanFrancisco,2",
-                "d1002,2018-10-03 14:38:16.650,10.30000,218,0.25000,California.SanFrancisco,3",
-                "d1003,2018-10-03 14:38:05.500,11.80000,221,0.28000,California.LosAngeles,2",
-                "d1003,2018-10-03 14:38:16.600,13.40000,223,0.29000,California.LosAngeles,2",
-                "d1004,2018-10-03 14:38:05.000,10.80000,223,0.29000,California.LosAngeles,3",
-                "d1004,2018-10-03 14:38:06.500,11.50000,221,0.35000,California.LosAngeles,3"
-        );
+    private static List<String> getRawData(int size) {
+        SimpleDateFormat format = new SimpleDateFormat(datePattern);
+        List<String> result = new ArrayList<>();
+        long current = System.currentTimeMillis();
+        Random random = new Random();
+        for (int i = 0; i < size; i++) {
+            String time = format.format(current + i);
+            int id = random.nextInt(10);
+            result.add("d" + id + "," + time + ",10.30000,219,0.31000,California.SanFrancisco,2");
+        }
+        return result.stream()
+                .sorted(Comparator.comparing(s -> s.split(",")[0])).collect(Collectors.toList());
     }
 
     private static Connection getConnection() throws SQLException {
@@ -48,9 +41,9 @@ public class StmtInsertExample {
 
     private static void createTable(Connection conn) throws SQLException {
         try (Statement stmt = conn.createStatement()) {
-            stmt.execute("CREATE DATABASE power KEEP 3650");
-            stmt.executeUpdate("USE power");
-            stmt.execute("CREATE STABLE meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) " +
+            stmt.execute("CREATE DATABASE if not exists power KEEP 3650");
+            stmt.executeUpdate("use power");
+            stmt.execute("CREATE STABLE if not exists meters (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) " +
                     "TAGS (location BINARY(64), groupId INT)");
         }
     }
@@ -58,21 +51,54 @@ public class StmtInsertExample {
     private static void insertData() throws SQLException {
         try (Connection conn = getConnection()) {
             createTable(conn);
-            String psql = "INSERT INTO ? USING meters TAGS(?, ?) VALUES(?, ?, ?, ?)";
+            String psql = "INSERT INTO ? USING power.meters TAGS(?, ?) VALUES(?, ?, ?, ?)";
             try (TSDBPreparedStatement pst = (TSDBPreparedStatement) conn.prepareStatement(psql)) {
-                for (String line : getRawData()) {
+                String tableName = null;
+                ArrayList<Long> ts = new ArrayList<>();
+                ArrayList<Float> current = new ArrayList<>();
+                ArrayList<Integer> voltage = new ArrayList<>();
+                ArrayList<Float> phase = new ArrayList<>();
+                for (String line : getRawData(100000)) {
                     String[] ps = line.split(",");
-                    // bind table name and tags
-                    pst.setTableName(ps[0]);
-                    pst.setTagString(0, ps[5]);
-                    pst.setTagInt(1, Integer.valueOf(ps[6]));
+                    if (tableName == null) {
+                        // bind table name and tags
+                        tableName = "power." + ps[0];
+                        pst.setTableName(ps[0]);
+                        pst.setTagString(0, ps[5]);
+                        pst.setTagInt(1, Integer.valueOf(ps[6]));
+                    } else {
+                        if (!tableName.equals(ps[0])) {
+                            pst.setTimestamp(0, ts);
+                            pst.setFloat(1, current);
+                            pst.setInt(2, voltage);
+                            pst.setFloat(3, phase);
+                            pst.columnDataAddBatch();
+                            pst.columnDataExecuteBatch();
+
+                            // bind table name and tags
+                            tableName = ps[0];
+                            pst.setTableName(ps[0]);
+                            pst.setTagString(0, ps[5]);
+                            pst.setTagInt(1, Integer.valueOf(ps[6]));
+                            ts.clear();
+                            current.clear();
+                            voltage.clear();
+                            phase.clear();
+                        }
+                    }
                     // bind values
-                    pst.setTimestamp(0, tsToLongArray(ps[1])); //ps[1] looks like: 2018-10-03 14:38:05.000
-                    pst.setFloat(1, toArray(Float.valueOf(ps[2])));
-                    pst.setInt(2, toArray(Integer.valueOf(ps[3])));
-                    pst.setFloat(3, toArray(Float.valueOf(ps[4])));
-                    pst.columnDataAddBatch();
+                    // ps[1] looks like: 2018-10-03 14:38:05.000
+                    LocalDateTime localDateTime = LocalDateTime.parse(ps[1], formatter);
+                    ts.add(localDateTime.toInstant(ZoneOffset.of("+8")).toEpochMilli());
+                    current.add(Float.valueOf(ps[2]));
+                    voltage.add(Integer.valueOf(ps[3]));
+                    phase.add(Float.valueOf(ps[4]));
                 }
+                pst.setTimestamp(0, ts);
+                pst.setFloat(1, current);
+                pst.setInt(2, voltage);
+                pst.setFloat(3, phase);
+                pst.columnDataAddBatch();
                 pst.columnDataExecuteBatch();
             }
         }