import java.sql.*;
import java.util.Properties;

public class Main {
 public static void main(String[] args) {
    try {
        Class.forName("org.postgresql.Driver");
        String url = "jdbc:postgresql://localhost:5432/Test";
        Properties props = new Properties();
        props.setProperty("user","postgre");
        props.setProperty("password","3333");
        Connection conn = DriverManager.getConnection(url, props);
    }
    catch (ClassNotFoundException e) {
        System.out.println("PostgreSQL JDBC driver not found.");
        e.printStackTrace();
    }
    catch (SQLException e) {
        System.out.println("Connection failure.");
        e.printStackTrace();
    }
 }
}

Connection failure.
org.postgresql.util.PSQLException: ВАЖНО: пользователь "postgre" не прошёл проверку подлинности (по паролю) (pgjdbc: autodetected server-encoding to be windows-1251, if the message is not readable, please check database logs and/or host, port, dbname, user, password, pg_hba.conf)
    at org.postgresql.core.v3.ConnectionFactoryImpl.doAuthentication(ConnectionFactoryImpl.java:514)
    at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:141)
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:192)
    at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
    at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:195)
    at org.postgresql.Driver.makeConnection(Driver.java:454)
    at org.postgresql.Driver.connect(Driver.java:256)
    at java.sql.DriverManager.getConnection(DriverManager.java:664)
    at java.sql.DriverManager.getConnection(DriverManager.java:208)
    at Main.main(Main.java:13)

Process finished with exit code 0