Generating documentation causes ClassNotFound from @ApiImplicitParam

[langecode]

Generating documentation from classes containing the @ApiImplicitParam annotation generates huge stack traces if the annotation does not contain either dataTypeClass or dataType parameter.

Q	A
Bug or feature request?	feature request
Which Swagger-Core version?	1.5.15
Which Java version?	9 build 181

When neither the dataTypeClass nor the dataType property of the the annotation is set an large exception stack trace is printed because the code tries to do classloading of the empty string (the default value for dataType). The type is defaulted to string anyway so maybe the default value in for dataType in the annotation might be set to string to avoid the large stack trace.

This can easily be reproduced generating documentation from a class that contains an @ApiImplicitParam annotation with no value set for either dataTypeClass nor dataType.

Failed to resolve '' into class
java.lang.ClassNotFoundException:
        at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
        at io.swagger.util.ReflectionUtils.loadClassByName(ReflectionUtils.java:49)
        at io.swagger.util.ReflectionUtils.typeFromString(ReflectionUtils.java:31)
        at io.swagger.jaxrs.Reader.readImplicitParam(Reader.java:475)
        at io.swagger.jaxrs.Reader.processImplicitParams(Reader.java:444)
        at io.swagger.jaxrs.Reader.readImplicitParameters(Reader.java:437)
        at io.swagger.jaxrs.Reader.read(Reader.java:425)
        at io.swagger.jaxrs.Reader.read(Reader.java:172)
        at io.swagger.jaxrs.Reader$read.call(Unknown Source)

[webron]

It sounds to me like the bug is that string is assumed. It should actually fail if no type is mentioned. The goal of the annotation is to let you describe parameters on top of the types defined in the method, which means that you are required to provide all details.

[langecode]

Yeah, that could also be the case. Its just that the current stack trace is rather confusing - took a little debugging to figure out what was happening :-)

[webron]

Yeah, that's understandable. Can definitely be improved.