我第一次尝试使用 JDBC 连接到本地数据库 (Postgres)，但我似乎无法真正建立连接。这是我的代码:
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!");
}
}
}
这是我尝试执行它时出现的错误:
-------- 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)
我使用 Fedora，但我不知道这是否相关。任何人都知道为什么会发生这种情况？
最佳答案
您在以下代码中的用户名/密码不正确:
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，将 ALTER USER "xxxx"WITH PASSWORD ''; 更改为您会记住的新密码。
硬编码登录细节也是一个非常糟糕的主意。
关于java - 连接到 Postgres 数据库失败，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/47079262/