Question

I'm trying for the first time to JDBC to connect to a local database (Postgres) but I can't seem to actually made the connection. This is my code:

import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.SQLException;

public class JDBCExample {

    public static void main(String[] argv) {

        System.out.println("-------- PostgreSQL "
                + "JDBC Connection Testing ------------");

        try {

            Class.forName("org.postgresql.Driver");

        } catch (ClassNotFoundException e) {

            System.out.println("Where is your PostgreSQL JDBC Driver? "
                    + "Include in your library path!");
            e.printStackTrace();
            return;

        }

        System.out.println("PostgreSQL JDBC Driver Registered!");

        Connection connection = null;

        try {

            connection = DriverManager.getConnection(
                    "jdbc:postgresql://localhost:5432/training", "iam47662285",
                    "MY56KZDZ");

        } catch (SQLException e) {

            System.out.println("Connection Failed! Check output console");
            e.printStackTrace();
            return;

        }

        if (connection != null) {
            System.out.println("You made it, take control your database now!");
        } else {
            System.out.println("Failed to make connection!");
        }
    }

}

And this is the error that appears when i try to execute it:

-------- PostgreSQL JDBC Connection Testing ------------
PostgreSQL JDBC Driver Registered!
Connection Failed! Check output console
Nov 02, 2017 4:36:52 PM org.postgresql.Driver connect
SEVERE: Connection error: 
org.postgresql.util.PSQLException: FATAL: password authentication failed for user "iam47662285"
    at org.postgresql.core.v3.ConnectionFactoryImpl.doAuthentication(ConnectionFactoryImpl.java:438)
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:222)
    at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
    at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:194)
    at org.postgresql.Driver.makeConnection(Driver.java:450)
    at org.postgresql.Driver.connect(Driver.java:252)
    at java.sql.DriverManager.getConnection(DriverManager.java:664)
    at java.sql.DriverManager.getConnection(DriverManager.java:247)
    at UF2.Pruebas.BDR_BDOO.JDBCExample.main(JDBCExample.java:33)

org.postgresql.util.PSQLException: FATAL: password authentication failed for user "iam47662285"
    at org.postgresql.core.v3.ConnectionFactoryImpl.doAuthentication(ConnectionFactoryImpl.java:438)
    at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:222)
    at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
    at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:194)
    at org.postgresql.Driver.makeConnection(Driver.java:450)
    at org.postgresql.Driver.connect(Driver.java:252)
    at java.sql.DriverManager.getConnection(DriverManager.java:664)
    at java.sql.DriverManager.getConnection(DriverManager.java:247)
    at UF2.Pruebas.BDR_BDOO.JDBCExample.main(JDBCExample.java:33)

I use Fedora, but i don't know if that's relevant. Anyone have any idea of why is this happening?

Answer 1

您的用户名/密码在以下代码中不正确：

        connection = DriverManager.getConnection(
                "jdbc:postgresql://localhost:5432/training", "iam47662285",
                "MY56KZDZ");

手动登录psql并验证正确的用户名/密码是什么。如有必要ALTER USER "xxxx" WITH PASSWORD '';，您将记住一个新的。

同样硬编码登录详细信息是一个非常糟糕的主意。

Connection to Postgres Database failes

1 个答案: