Converting XML to POGO

Suppose we want to convert XML to Groovy bean:

class MyBean {
    String strField
    float floatField
    int intField
    boolean boolField
}

def message = "<xml stringAttr='String Value' boolAttr='true' />"

def xml = new XmlSlurper().parseText(message)

def bean = new MyBean(
    strField: xml.@stringAttr,
    boolField: xml.@boolAttr
)

Everything looks good, even assertions succeed

assert 'String Value' == bean.strField
assert bean.boolField

Now let's try false value:

message = "<xml stringAttr='String Value' boolAttr='false' />"
assert !bean.boolField

Oops, the assertion failed. Why? Because xml.@boolAttr cast to boolean always returns true. The correct implementation must be like this:

message = "<xml stringAttr='String Value' floatAttr='3.14' intAttr='9' boolAttr='false' />"

xml = new XmlSlurper().parseText(message)

bean = new MyBean(
    strField: xml.@stringAttr.toString(),
    floatField: xml.@floatAttr.toFloat(),
    intField: xml.@intAttr.toInteger(),
    boolField: xml.@boolAttr.toBoolean()
)
assert 'String Value' == bean.strField
assert 3.14F == bean.floatField
assert 9 == bean.intField
assert !bean.boolField

Now everything works properly. The moral of this blog post: Create more unit tests (assertions), especially when you work with dynamic language.

Resources

• Converting String to Boolean