Question

我试图通过jdbc访问PostgreSQL。下面的代码不是从Eclipse运行的，但它确实从命令行运行。有什么建议我如何从Eclipse运行它？ postgresql-9.4.1211.jar位于CLASSPATH中，与下面的包非常不同。 Windows 7，java 1.8.0.101.b13，postgres 9.5.3，Eclipse 4.5.1

package PostTest;

import java.sql.*;
import java.util.logging.Level;
import java.util.logging.Logger;

public class Version 
{

   public static void main(String[] args) 
   {

      Connection con = null;
      Statement st = null;
      ResultSet rs = null;


      String url = "jdbc:postgresql://localhost/nederland";
      String user = "postgres";
      String password = "Hallo Postgres!";

      System.out.println ("Testing for driver");

      try 
      {
         Class.forName("org.postgresql.Driver");
         // Success.
         System.out.println ("driver found");
      } catch (ClassNotFoundException e) 
      {
         // Fail.
         System.out.println ("driver lost");
      }

      System.out.println ("Trying to connect");
      try 
      {
         con = DriverManager.getConnection(url, user, password);
         st = con.createStatement();
         rs = st.executeQuery("SELECT VERSION()");

         if (rs.next()) {
            System.out.println(rs.getString(1));
         }

      } catch (SQLException ex) 
      {
         Logger lgr = Logger.getLogger(Version.class.getName());
         lgr.log(Level.SEVERE, ex.getMessage(), ex);

      } finally 
      {
         try 
         {
            if (rs != null) 
            {
               rs.close();
            }
            if (st != null) 
            {
               st.close();
            }
            if (con != null) 
            {
               con.close();
            }

         } catch (SQLException ex) 
         {
            Logger lgr = Logger.getLogger(Version.class.getName());
            lgr.log(Level.WARNING, ex.getMessage(), ex);
         }
      }
   }
}

从Eclipse运行时，我得到：

Testing for driver
driver lost
Trying to connect
Oct 07, 2016 8:43:02 PM PostTest.Version main
SEVERE: No suitable driver found for jdbc:postgresql://localhost/nederland
java.sql.SQLException: No suitable driver found for jdbc:postgresql://localhost/nederland
    at java.sql.DriverManager.getConnection(Unknown Source)
    at java.sql.DriverManager.getConnection(Unknown Source)
    at PostTest.Version.main(Version.java:38)

从命令行运行时：

D:\home\arnold\development\java\projects\PostTest\bin>java PostTest.Version
Testing for driver
driver found
Trying to connect
PostgreSQL 9.5.3, compiled by Visual C++ build 1800, 64-bit

Answer 1

如果PostgreSQL库在您的项目中（例如/ lib文件夹），请右键单击它 - ＆gt;构建路径 - ＆gt; 添加到构建路径。

如果您的项目中没有库，请右键单击您的项目 - ＆gt;构建路径 - ＆gt; 配置构建路径... 然后单击Libraries选项卡并添加外部JAR ... 然后选择postgresql-9.4.1211.jar文件并单击OK。

在Eclipse中找不到JDBC驱动程序，但在独立运行时找到了

1 个答案: