package vas;
import java.sql.*;
public class ConnTO {
public Connection conn;
private String db;
public ConnTO(String db) throws Exception{
this.db=db;
//Trying to get the driver
try {
Class.forName("org.postgresql.Driver");
}
catch (java.lang.ClassNotFoundException e) {
java.lang.System.err.print("ClassNotFoundException: Postgres Server JDBC");
java.lang.System.err.println(e.getMessage());
throw new Exception("No JDBC Driver found in Server");
}
//Trying to connectpostgresql:/
try {
conn = DriverManager.getConnection("jdbc:postgresql://localhost:5432/"+db,"postgres","211271");
//conn.setCatalog(db);
System.out.println("Connection with: "+db+"!!");
}
catch (SQLException E) {
java.lang.System.out.println("SQLException: " + E.getMessage());
java.lang.System.out.println("SQLState: " + E.getSQLState());
java.lang.System.out.println("VendorError: " + E.getErrorCode());
}
}
//Close Conn
public void close() throws SQLException{
try {
conn.close();
System.out.println("Connection close ");
} catch (SQLException E) {
java.lang.System.out.println("SQLException: " + E.getMessage());
java.lang.System.out.println("SQLState: " + E.getSQLState());
java.lang.System.out.println("VendorError: " + E.getErrorCode());
throw E;
}
}
}
您好,我用 postgresql 创建了一个数据库,我想用 java 连接它,但是当我运行它时出现错误,例如
ClassNotFoundException: Postgres Server JDBCorg.postgresql.Driver
java.lang.Exception: No JDBC Driver found in Server
at vas.ConnTO.<init>(ConnTO.java:21)
at vas.main.login(main.java:17)
at vas.main.main(main.java:51)
我还有一个主类,我称之为 connto 类,我给出了我的基础名称