O'Reilly Book Excerpts: Java and Soap

Working with Complex Data Types, Part 4

Related Reading Java and SOAP By Robert Englander

by Robert Englander

This is the last in a series of book excerpts from Java and SOAP on working with complex data types. In this excerpt, learn about returning custom types, using a stock market example.

Returning Custom Types

It's equally useful (and equally common) to return custom types from service method calls. We can enhance our trading service by offering a method that takes a single stock symbol as a parameter and returns its high and low trading prices for the day. The classes HighLow_ServerSide and HighLow_ClientSide represent the high/low prices on the server and client, respectively.

package javasoap.book.ch5;
public class HighLow_ServerSide {
   public float _high;
   public float _low;
   public HighLow_ServerSide(  ) {
   }
   public HighLow_ServerSide (float high, float low) {
      setHigh(high);
      setLow(low);
   }
   public float getHigh(  ) {
      return _high;
   }
   public void setHigh(float high) {
      _high = high;
   }
   public float getLow(  ) {
      return _low;
   }
   public void setLow(float low) {
      _low = low;
   }
}
  
package javasoap.book.ch5;
public class HighLow_ClientSide {
   public float _high;
   public float _low;
   public String toString(  ) {
      return "High: " + _high +
        " Low: " + _low;
   }
   public HighLow_ClientSide(  ) {
   }
   public float getHigh(  ) {
      return _high;
   }
   public void setHigh(float high) {
      _high = high;
   }
   public float getLow(  ) {
      return _low;
   }
   public void setLow(float low) {
      _low = low;
   }
}

In This Series Working with Complex Data Types, Part 3 The third in a series of excerpts from Java and SOAP, this article excerpt covers passing custom types as parameters. Working with Complex Data Types, Part 2 In part two in this series of book excerpts from Java and SOAP, learn about returning arrays. Working with Complex Data Types, Part 1 In this excerpt on complex data types from Java and SOAP, the authors discuss passing arrays as parameters.

The server-side class includes a parameterized constructor as a convenience for creating the return value; the client-side class includes a toString( ) method to make it easy for our client application to display the contents of the object after it's returned from the server. Let's add a new method to the BasicTradingService class called getHighLow( ). That method takes a single string parameter for the stock symbol and returns an instance of HighLow_ServerSide. Here's the class with its new method, with the unchanged code omitted:

package javasoap.book.ch5;
public class BasicTradingService {
   public BasicTradingService(  ) {
   }
   . . .
   . . .
   public HighLow_ServerSide getHighLow(String stock) {
      
      // retrieve the high and low for the specified stock
      return new HighLow_ServerSide((float)110.375, 
                      (float)109.5);
   }
}

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