I am currently working on building a fluent interface over soap toolkits. I did discussed the possibilities of rich APIs value addition. One of the problem with fluent APIs is that we have to get rid of checked exception to make it easier, but there are cases where fault containment is necessary. I am just thinking the better appraoach would be to generate the unchecked Exception counterparts for each of the fault code & provide the easier error handling.

For Example: (I have modified sample shown by the Martin Fowler), Let us assume that newOrder process will talk to 2 other web services & there is possibilities of 2 soapfault errors.

import static test.Customer.newOrder;

private void orderNew(){
newOrder() .
with(6, "TAL") .with(5, "HPK").skippable()
.withDollar(35.d) .withAccountId(23423l).withLicense("AS900980") .
.with(3, "LGV")
.priorityRush();
}
@Test
public void test(){
try{
orderNew();
}catch(GenricException exp){
switch(exp.getErrorCode()){
case SOAPFaultsCodes.E1001:
// handle the exception possibly giving more useful message or some other recovery action
case SOAPFaultsCodes.7003:
}
throw new RuntimeException("Unhandled Error");
}
}

Here again GenericExcption is abstract Exception extedning RuntimeException that is implemented by all the soap fault exception correspding to the errorcode & will be thrown by the rich APIs.

I guess with JDK7 I guess we can have String based switch() & upgraded catch block.

Well, for unit testing exception we can laverege the annotations support to assert with JUnit4
@Test(expected = E7069Exception.class)

I wanted to generate all these Exceptions automatically from soap faults document, For that I wrote this groovy script. (show casing the usage of multiline string, closure & file I/O)

constantsFile=""
converFileLineIntoException = {
sarray = it.split(" ")
exception = sarray[0]+"Exception"
errorCode = exception.substring(1,sarray[0].length())
constantsFile+="\n public static final int E$errorCode = $errorCode;"
className =
"""package com.yahoo.sm.ws.builders.exception;
// Generated code
public class $exception extends GenericException {

private String description;
private String shortDescription;

public $exception(String description, String shortDescription){
this.description=description;
this.shortDescription=shortDescription;
}

public int errorCode(){
return $errorCode;
}

public String getDescription(){
return this.description;
}

public String shortDescription(){
return this.shortDescription;
}
}
"""
new File(sarray[0]+"Exception.java").write(className)
}

def lines = new File("soapFaultList.txt").eachLine(converFileLineIntoException)
soapFaults = """
package com.yahoo.sm.ws.builders.exception;
public interface SOAPFaultsCodes {
$constantsFile
}"""
new File("SOAPFaultsCodes.java").write(soapFaults)
println "--- Gr8 I am done "

Groovy, JUnit4 & static imports just rocks :-)