First, the current popular WebService framework introduction:
①Apache Axis2
Apache Axis2 is more efficient, more modular, and more XML-oriented than Apache Axis1, and supports easy plug-in modules to extend new functions and features, such as security and reliability. Apache Axis2 is based on Apache AXIOM, a high-performance, pull-based XML object model. Key features of Apache Axis2:
l Parse xml faster. Adopt own object model and StAX (Streaming API for XML).
l Lower memory usage.
l Support hot deployment. New services are added to the system without restarting the service.
l Support asynchronous webservice,
l More flexible. The engine provides developers with sufficient freedom to expand client header information processing, system management,
l More stable.
l Support WSDL1.1, WSDL2.0.
l It is convenient to integrate other components (Add-ons). Several web services have been integrated, including: WSS4J for security (Apache Rampart), Sandesha for reliable messaging, Kandula which is an encapsulation of WS-Coordination, WS-AtomicTransaction and WS-BusinessActivity.
l Good scalability.
②Apache Axis2
Apache CXF is an open source serving framework. Apache CXF = Celtix + XFire, the predecessor of Apache CXF was called Apache CeltiXfire, and now it has been officially renamed Apache CXF, hereinafter referred to as CXF. CXF inherits the essence of two open source projects, Celtix and XFire, such as: JAX-WS and JAX-RS. The main features include:
l 支持Web services标准。包括：SOAP、the WSI Basic Profile、WSDL、WS-Addressing、WS-Policy、WS-ReliableMessaging、WS-Security、WS-SecureConversation和WS-SecurityPolicy.
l Support different types of front-end development models . CXF implements JAX-WS APIs and supports JAX-RS development.
l Easy to use. CXF is designed to be concise and intuitive, with concise APIs to quickly build code-based services, Maven plugins for easier tool integration, JAX-WS API support, and Spring 2.x XML for easier configuration.
l Support binary and legacy protocols. CXF is designed as a pluggable architecture that supports not only XML, but also non-XML type bindings, such as JSON and CORBA, under the combination of different transport protocols.
③Apache Axis2
Dubbo is Alibaba's open source distributed service framework. Its biggest feature is that it is structured in a layered manner, which can decouple (or maximize loose coupling) between layers.
2. Concept introduction
①, Web Service is also called XML Web Service WebService is a lightweight independent communication technology that can receive requests from other systems on the Internet or Intranet. Yes: Software services provided on the Web via SOAP, described using WSDL files, and registered via UDDI.
②, SOAP protocol : Simple Object Access Protocol, Simple Object Access Protocol is a protocol specification for exchanging data, is a lightweight, simple, XML -based protocol, it is designed to exchange structured and solidified information. SOAP is one of the three elements of SOAP , WSDL and UUID in webService. SOAP is used to describe the format of transferring information, WSDL is used to describe how to access specific interfaces, and uddi is used to manage, distribute and query webService. SOAP can be used in conjunction with many existing Internet protocols and formats, including Hypertext Transfer Protocol ( HTTP), Simple Mail Transfer Protocol ( SMTP), and Multipurpose Internet Mail Extensions ( MIME). It also supports a wide variety of applications ranging from messaging systems to remote procedure calls ( RPCs) . SOAP uses XML-based data structures and Hypertext Transfer ProtocolThe (HTTP) composition defines a standard way to use distributed objects in a variety of different operating environments on the Internet .
③. The JAX-WS specification is a set of JAVA APIs for XML web services . JAX-WS allows developers to choose RPC-oriented or message-oriented to implement their own web services.
In JAX-WS, a remote call can be converted to an XML-based protocol such as SOAP. In the process of using JAX-WS, the developer does not need to write any code to generate and process SOAP messages. The runtime implementation of JAX-WS translates these API calls into corresponding SOAP messages. On the server side, the user only needs to define the interface SEI ( service endpoint interface) that needs to be implemented for remote invocation through Java language , and provide the relevant implementation, which can be published as a WebService interface by calling the service publishing interface of JAX-WS. On the client side, the user can create a proxy (replacing remote services with local objects) through the JAX-WS API to implement calls to the remote server side. Of course, JAX-WS also provides a set of API calls that operate on the underlying messages. You can directly use SOAP messages or XML messages to send requests through Dispatch, or use Provider to process SOAP or XML messages.
Through the interoperability environment provided by web service, we can use JAX-WS to easily realize the interoperability between the JAVA platform and other programming environments ( .net, etc.).
three,