Daten auslesen und auswerten

.gitignore

@@ -43,3 +43,4 @@ buildNumber.properties
 hs_err_pid*
 replay_pid*
 
+/db-password.txt

src/main/java/info/peper/vz/rest/ReadDbMain.java

@@ -1,16 +1,92 @@
 package info.peper.vz.rest;
 
+import java.io.BufferedReader;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
 import java.time.Instant;
-import java.time.OffsetDateTime;
+import java.time.ZoneId;
 import java.time.format.DateTimeFormatter;
+import java.time.temporal.ChronoUnit;
 import java.time.temporal.TemporalAccessor;
 
 public class ReadDbMain {
 
+	private static final DateTimeFormatter DTF = DateTimeFormatter.ISO_LOCAL_DATE_TIME.withZone(ZoneId.systemDefault());
+	
 	public static void main(String[] args) throws Exception {
-		final DateTimeFormatter dtf = DateTimeFormatter.ISO_LOCAL_DATE_TIME;
-		System.out.println(dtf.format(OffsetDateTime.now()));
-		final TemporalAccessor test = dtf.parse("2025-02-22T00:00:00");
+		try (final Connection con = DriverManager.getConnection(
+				"jdbc:mariadb://mariadb.fritz.box/volkszaehler",
+				"vz",
+				getPassword())) {
+			long startTimeStamp = getTimestamp("2023-01-01T00:00:00");
+			long endTimeStamp = startTimeStamp + (24*60*60*1000);
+			final long finalEndTimeStamp = getTimestamp("2025-02-23T00:00:00");
+			while (endTimeStamp < finalEndTimeStamp) {
+				final long[] zaehler = getValues(con, startTimeStamp, endTimeStamp, 1);
+				final long[] solar = getValues(con, startTimeStamp, endTimeStamp, 4);
+				System.out.println(DTF.format(Instant.ofEpochMilli(startTimeStamp)) +
+						"\t" +
+						DTF.format(Instant.ofEpochMilli(endTimeStamp)) +
+						"\t" +
+						zaehler[0] +
+						"\t" +
+						zaehler[1] +
+						"\t" +
+						solar[0]
+						);
+				startTimeStamp += 24*60*60*1000;
+				endTimeStamp += 24*60*60*1000;
+			}
+		}
+	}
+	
+	private static String getPassword() throws IOException {
+		try (final InputStream is = new FileInputStream("db-password.txt")) {
+			final BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is));
+			return bufferedReader.readLine();
+		}
+	}
+
+	private static long getTimestamp(final String dateTime) {
+		final TemporalAccessor tempAccessor = DTF.parse(dateTime);
+		final Instant instant = Instant.from(tempAccessor);
+		return Instant.EPOCH.until(instant, ChronoUnit.MILLIS);
+	}
+	
+	private static long[] getValues(final Connection con,
+			final long startTimestamp,
+			final long endTimestamp,
+			final int channelId) throws SQLException {
+		try (final PreparedStatement stmt = con.prepareStatement("SELECT * FROM volkszaehler.data WHERE channel_id=? AND timestamp>? AND timestamp<=? ORDER BY timestamp;")) {
+			long currentTimestamp = startTimestamp;
+			long wattMillisecondsPos = 0;
+			long wattMillisecondsNeg = 0;
+			stmt.setInt(1, channelId);
+			stmt.setLong(2, startTimestamp);
+			stmt.setLong(3, endTimestamp + 1*60*1000);
+			try (final ResultSet rs = stmt.executeQuery()) {
+				while (rs.next() && currentTimestamp <= endTimestamp) {
+					final long rsTimestamp = rs.getLong("timestamp");
+					final long rsValue = rs.getLong("value");
+					final long tsDiff = rsTimestamp - Math.min(endTimestamp, currentTimestamp);
+					currentTimestamp = rsTimestamp;
+					if (rsValue > 0) {
+						wattMillisecondsPos += (rsValue * tsDiff);
+					} else if (rsValue < 0) {
+						wattMillisecondsNeg += (-rsValue * tsDiff);
+					}
+				}
+			}
+			return new long[] {wattMillisecondsPos/3600, wattMillisecondsNeg/3600};
+		}
+
 	}
 	
 }