Using DynamicClassLoader

Use the CLASS_LOADER connection property to provide a convenient mechanism for sharing one class loader among several connections.

1. Create and configure a class loader.
   The code for your SAP jConnect application should look similar to this:

   Properties props = new Properties();// URL of the server where the classes live.
   String classesUrl = "jdbc:sybase:Tds:myase:1200"; // Connection properties for connecting to above server.
   props.put("user", "grinch");
   props.put("password", "meanone");
   ... // Ask the SybDriver for a new class loader.
   DynamicClassLoader loader = driver.getClassLoader(classesUrl, props);

2. Use the CLASS_LOADER connection property to make the new class loader available to the statement that executes the query.
   Once you create the class loader, pass it to subsequent connections as shown (continuing from the code example in step 1):

   // Stash the class loader so that other connection(s)
   // can know about it.
   props.put("CLASS_LOADER", loader);// Additional connection properties
   props.put("user", "joeuser");
   props.put("password", "joespassword");// URL of the server we now want to connect to.
   String url = "jdbc:sybase:Tds:jdbc.sybase.com:4446";// Make a connection and go.
   Connection conn = DriverManager.getConnection(url, props);

   Assume the Java class definition is:

   class Addr {
         String street;
         String city;
         String state;
   }

   Assume the SQL table definition:

   create table employee (char(100) name, int empid, Addr address)

3. Use the client-side code in the absence of an Addr class in the client application CLASSPATH:

   Statement stmnt = conn.createStatement();

   // Retrieve some rows from the table that has a Java class
   // as one of its fields.

   ResultSet rs = stmnt.executeQuery(

         "select * from employee where empid = ’19’");

   if (rs.next() {

         // Even though the class is not in our class path,

         // we should be able to access its instance.

         Object obj = rs.getObject("address");

         // The class has been loaded from the server, so let's take a look.

         Class c = obj.getClass();

       // Some Java Reflection can be done here to access the fields of obj.

         ...

   }