pgdjbc BatchUpdateException test

gistfile1.txt

import java.sql.BatchUpdateException;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Arrays;

public class PostgresBatchUpdate {

    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        Class.forName("org.postgresql.Driver");

        String jdbcurl = "jdbc:postgresql:test";
        String user = "postgres";
        String passwd = "geheim";

        Connection con = DriverManager.getConnection(jdbcurl, user, passwd);
        con.setAutoCommit(true);

        DatabaseMetaData dmd = con.getMetaData();
        System.out.println("DB: " + dmd.getDatabaseProductName() + " " + dmd.getDatabaseProductVersion());
        System.out.println("Driver: " + dmd.getDriverName() + " " + dmd.getDriverVersion());

        // create table when absent
        Statement s = con.createStatement();
        s.execute("create table if not exists TEST (ID varchar(512) not null primary key, DATA varchar(512))");
        s.close();

        // clean up
        PreparedStatement st = con.prepareStatement("DELETE FROM test WHERE ID in (?, ?)");
        st.setString(1, "key-1");
        st.setString(2, "key-2");
        st.executeUpdate();
        st.close();

        // insert "key-2"
        st = con.prepareStatement("INSERT INTO test (id) VALUES (?)");
        st.setString(1, "key-2");
        st.executeUpdate();
        st.close();

        // update as batch
        PreparedStatement batchSt = con.prepareStatement("INSERT INTO test (id) VALUES (?)");
        batchSt.setString(1, "key-1");
        batchSt.addBatch();

        batchSt.setString(1, "key-2");
        batchSt.addBatch();

        boolean wasKey1Inserted = false;
        try {
            int[] batchResult = batchSt.executeBatch();
            batchSt.close();
            System.out.println("update unexpectedly succeeded: " + Arrays.toString(batchResult));
        }
        catch (BatchUpdateException ex) {
            int[] batchResult = ex.getUpdateCounts();
            System.out.println("update failed as expected: " + Arrays.toString(batchResult));
            wasKey1Inserted = batchResult.length >= 1 && batchResult[0] == 1;
            if (wasKey1Inserted) {
                System.out.println("batch result implies that first operation (insert of key-1) suceeded");
            }
        }
        con.close();

        if (wasKey1Inserted) {
            con = DriverManager.getConnection(jdbcurl, user, passwd);
            con.setAutoCommit(true);
            boolean foundKey1 = false;

            PreparedStatement q = con.prepareStatement("SELECT ID FROM test");
            ResultSet r = q.executeQuery();
            while (r.next()) {
                System.out.println("Found: " + r.getString(1));
                foundKey1 |= ("key-1".equals(r.getString(1)));
            }

            if (!foundKey1) {
                System.out.println("Error: 'key-1' not found");
            }
        }
    }
}