java.sql.SQLException: No suitable driver found for jdbc:derby:

问题

I'm a beginner with jdbc ... I have a problem running this code :

This code uses appache derby and in order to make it work I first started the derby server..

      java -jar "C:\Program Files\Sun\JavaDB\lib\derbyrun.jar" server start

And then started the program

      java -classpath derbyclient.jar -jar TestDB.jar

I set the class path C:\Program Files\Sun\JavaDB\lib\derby.jar

And I'm always getting that exception

java.sql.SQLException: No suitable driver found for jdbc:derby://localhost:1527/ BOOKDB;create=true at java.sql.DriverManager.getConnection(DriverManager.java:602) at java.sql.DriverManager.getConnection(DriverManager.java:185) at TestDB.getConnection(TestDB.java:63) at TestDB.runTest(TestDB.java:20) at TestDB.main(TestDB.java:11)

import java.sql.*;
import java.io.*;
import java.util.*;


class TestDB
{
   public static void main(String args[])
   {
      try
      {
         runTest();
      }
      catch (SQLException ex)
      {
         for (Throwable t : ex)
            t.printStackTrace();
      }
      catch (IOException ex)
      {
         ex.printStackTrace();
      }
   }

   public static void runTest() throws SQLException, IOException
   {
      Connection conn = getConnection();
      try
      {
         Statement stat = conn.createStatement();

         stat.executeUpdate("CREATE TABLE Greetings (Message CHAR(20))");
         stat.executeUpdate("INSERT INTO Greetings VALUES ('Hello, World!')");

         ResultSet result = stat.executeQuery("SELECT * FROM Greetings");
         if (result.next())
            System.out.println(result.getString(1));
         result.close();
         stat.executeUpdate("DROP TABLE Greetings");
      }
      finally
      {
         conn.close();
      }
   }

   public static Connection getConnection() throws SQLException, IOException
   {
      Properties props = new Properties();
      FileInputStream in = new FileInputStream("database.properties");
      props.load(in);
      in.close();

      String drivers = props.getProperty("jdbc.drivers");
      if (drivers != null) System.setProperty("jdbc.drivers", drivers);
      String url = props.getProperty("jdbc.url");
      String username = props.getProperty("jdbc.username");
      String password = props.getProperty("jdbc.password");

      return DriverManager.getConnection(url, username, password);
   }
}

回答1:

When you invoke the java command with the -jar and -classpath parameters, the -classpath parameter is ignored. See the documentation for the Java launcher.

You can either use:

Unix/Linux:

java -classpath derbyclient.jar:TestDB.jar TestDB

Windows:

java -classpath derbyclient.jar;TestDB.jar TestDB

or make a manifest which adds derbyclient.jar to the classpath.

回答2:

When you use -jar, -classpath is ignored. From the java command tool docs:

When you use this option, the JAR file is the source of all user classes, and other user class path settings are ignored.

Either use -classpath without -jar and specify the type containing the main method explicitly, or make your jar file manifest reference the derby jar file.

来源：https://stackoverflow.com/questions/1375954/java-sql-sqlexception-no-suitable-driver-found-for-jdbcderby

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java

jdbc

driver

derby