+
−import org.monetdb.jdbc.MonetConnection;
+
−import org.monetdb.jdbc.MonetConnection.UploadHandler;
+
−
+
−import java.io.BufferedReader;
+
−import java.io.IOException;
+
−import java.io.InputStream;
+
−import java.io.PrintStream;
+
−import java.nio.file.FileSystems;
+
−import java.nio.file.Files;
+
−import java.nio.file.Path;
+
−import java.sql.*;
+
−
+
−public class OnClientExample {
+
−
+
−	public static void main(String[] args) {
+
−		int status = 0;
+
−		try {
+
−			// Ideally this would not be hardcoded..
+
−			final String dbUrl = "jdbc:monetdb://localhost:55000/banana";
+
−			final String uploadDir = "/home/jvr/mydata";
+
−			final boolean filesAreUtf8 = false;
+
−			final String userName = "monetdb";
+
−			final String password = "monetdb";
+
−
+
−			status = run(dbUrl, userName, password, uploadDir, filesAreUtf8);
+
−
+
−		} catch (Exception e) {
+
−			status = 1;
+
−			e.printStackTrace();
+
−		}
+
−		System.exit(status);
+
−	}
+
−
+
−	private static int run(String dbUrl, String userName, String password, String uploadDir, boolean filesAreUtf8) throws ClassNotFoundException, SQLException {
+
−		int status = 0;
+
−
+
−		// Connect
+
−		Class.forName("org.monetdb.jdbc.MonetDriver");
+
−		Connection conn = DriverManager.getConnection(dbUrl, userName, password);
+
−
+
−		// Register upload handler
+
−		MyUploader handler = new MyUploader(uploadDir, filesAreUtf8);
+
−		conn.unwrap(MonetConnection.class).setUploadHandler(handler);
+
−
+
−		// Run some SQL statements involving ON CLIENT
+
−		String[] queries = {
+
−				"DROP TABLE IF EXISTS bar",
+
−				"CREATE TABLE bar(i INT, t TEXT)",
+
−				"COPY INTO bar FROM 'generated.csv' ON CLIENT",
+
−				"COPY INTO bar FROM 'file.csv' ON CLIENT",
+
−				// following statement will run even if file.csv does not exist
+
−				"SELECT COUNT(*) FROM bar",
+
−		};
+
−		Statement stmt = conn.createStatement();
+
−		for (String q : queries) {
+
−			System.out.println(q);
+
−			try {
+
−				stmt.execute(q);
+
−				ResultSet rs = stmt.getResultSet();
+
−				if (rs == null) {
+
−					System.out.printf("  OK, %d rows updated%n", stmt.getUpdateCount());
+
−				} else {
+
−					long count = 0;
+
−					while (rs.next()) {
+
−						count++;
+
−					}
+
−					System.out.printf("  OK, returned %d rows%n", count);
+
−				}
+
−			} catch (SQLNonTransientException e) {
+
−				throw e;
+
−			} catch (SQLException e) {
+
−				System.out.println("  => SQL ERROR " + e.getMessage());
+
−				status = 1;
+
−			}
+
−		}
+
−
+
−		return status;
+
−	}
+
−
+
−
+
−	private static class MyUploader implements UploadHandler {
+
−		private final Path uploadDir;
+
−		private final boolean filesAreUtf8;
+
−
+
−		public MyUploader(String uploadDir, boolean filesAreUtf8) {
+
−			this.uploadDir = FileSystems.getDefault().getPath(uploadDir).normalize();
+
−			this.filesAreUtf8 = filesAreUtf8;
+
−		}
+
−
+
−		@Override
+
−		public void handleUpload(MonetConnection.Upload handle, String name, boolean textMode, int offset) throws IOException {
+
−
+
−			// COPY OFFSET line numbers are 1-based but 0 is also allowed.
+
−			// Compute the number of lines to skip
+
−			long toSkip = offset <= 1 ? 0 : offset - 1;
+
−
+
−			// We can upload data read from the file system but also make up our own data
+
−			if (name.equals("generated.csv")) {
+
−				uploadGenerated(handle, toSkip);
+
−				return;
+
−			}
+
−
+
−			// Validate the path, demonstrating two ways of dealing with errors
+
−			Path path = securityCheck(name);
+
−			if (path == null || !Files.exists(path)) {
+
−				// This makes the COPY command fail but keeps the connection alive.
+
−				// Can only be used if we haven't sent any data yet
+
−				handle.sendError("Invalid path");
+
−				return;
+
−			}
+
−			if (!Files.isReadable(path)) {
+
−				// As opposed to handle.sendError(), throwing an IOException ends the whole connection.
+
−				throw new IOException("Unreadable: " + path);
+
−			}
+
−
+
−			boolean binary = !textMode;
+
−			if (binary) {
+
−				uploadBinary(handle, path);
+
−			} else if (toSkip == 0 && filesAreUtf8) {
+
−				// Avoid unnecessary character set conversions by pretending it's binary
+
−				uploadBinary(handle, path);
+
−			} else {
+
−				// Charset and skip handling really necessary
+
−				uploadTextFile(handle, path, toSkip);
+
−			}
+
−		}
+
−
+
−		private Path securityCheck(String name) {
+
−			Path p = uploadDir.resolve(name).normalize();
+
−			if (p.startsWith(uploadDir)) {
+
−				return p;
+
−			} else {
+
−				return null;
+
−			}
+
−		}
+
−
+
−		private void uploadGenerated(MonetConnection.Upload handle, long toSkip) throws IOException {
+
−			PrintStream stream = handle.getStream();
+
−			for (long i = toSkip + 1; i <= 100; i++) {
+
−				stream.printf("%d|the number is %d%n", i, i);
+
−			}
+
−			stream.close();
+
−		}
+
−
+
−		private void uploadTextFile(MonetConnection.Upload handle, Path path, long toSkip) throws IOException {
+
−			BufferedReader reader = Files.newBufferedReader(path);// Converts from system encoding to Java text
+
−			for (long i = 0; i < toSkip; i++) {
+
−				reader.readLine();
+
−			}
+
−			handle.uploadFrom(reader); // Converts from Java text to UTF-8 as required by MonetDB
+
−		}
+
−
+
−		private void uploadBinary(MonetConnection.Upload handle, Path path) throws IOException {
+
−			// No charset conversion whatsoever..
+
−			// Use this for binary data or when you are certain the file is UTF-8 encoded.
+
−			InputStream stream = Files.newInputStream(path);
+
−			handle.uploadFrom(stream);
+
−		}
+
−	}
+
−}