Web Service & SOA 学习笔记-3 关于WSDL（1）

wsdl的一般格式如左图：其中对于definations要注意几点：
• A namespace is qualified in an XML document through a QNAME. The QNAME is
the value following xmlns: in an XML document. It is a value used to qualify an
element within the XML document. If two elements imported from different
namespaces have the same name, they are qualified by using the QNAME followed by
a colon.（还有，不要把namespace"当真"）
• The default namespace used on elements (also known as the default qualifier) is the
namespace that follows the xmlns= attribute in an XML definition. If two conflicting
elements come from different namespaces, the element defined in the namespace
identified by xmlns= is used.
• The targetNamespace creates a unique identifier of the namespace created in the
WSDL document. Since the WSDL document defines new elements and attributes, the
value of this attribute is the identifier given to the namespace to which those elements
belong.
• It is common practice to further qualify the target namespace by creating a QNAME
named tns that points to the same value of targetNamespace. Thus,
targetNamespace creates a new namespace, and tns becomes the QNAME for
identifying "this namespace" within the same WSDL document.（tns是当前wsdl的namespace）。
对于import，有点像include，它使得wsdl具有了模块化的能力，对不同类型的资源引用进行分类，然后可以通过import实现了wsdl的"重用"。
今天已经很晚了，明天再看它的其他几个tag吧。