spring boot-实现WebService(CXF实现)的拦截器(Interceptor)

拦截器（Interceptor）是CXF功能最主要的扩展点，可以在不对核心模块进行修改的情况下，动态添加很多功能。拦截器和JAX-WS Handler、Filter的功能类似，当服务被调用时，就会创建一个拦截器链（Interceptor Chain），拦截器链在服务输入（IN）或输出（OUT）阶段实现附加功能。

拦截器可以在客户端，也可以在服务端添加。当客户端发起一个WebService请求时，在客户端会创建输出拦截器链(outinterceptor)，服务端接收到客户端的后，会创建输入拦截器链(ininterceptor)。当服务端返回响应消息时，响应消息会经过服务端的输出拦截链，客户端接收到服务端的响应时，会创建输入拦截器链，响应消息先经过输入拦截器链处理。拦截器在服务端和客户端的作用如图所示。

注：上图来源于网络。

下面，我们以一个Header认证为例，来演示CXF的拦截器的使用。

1、客户端拦截器

public class ClientAuthorInterceptor extends AbstractPhaseInterceptor {

	/**
	 * 客户端申请的token信息
	 */
	private String token;
	
	public ClientAuthorInterceptor(String token) {
		// 设置拦截器的时机，在发送请求到服务端之前进行拦截
		super(Phase.PREPARE_SEND);
		this.token = token;
	}

	@Override
	public void handleMessage(SoapMessage soap) throws Fault {
     // 在soap消息中添加认证头信息
     List
 headers = soap.getHeaders();
		Document doc = DOMUtils.createDocument();
		Element auth = doc.createElement(AuthorHeader.HEADER_NAME);
		Element token = doc.createElement(AuthorHeader.HEADER_TOKEN);
		token.setTextContent(this.token);
		auth.appendChild(token);
		Header header = new SoapHeader(new QName(AuthorHeader.HEADER_NAME), auth);
		headers.add(header);
	}
}

注意：客户端是outinterceptor

2、服务端拦截器

下面，服务端对发送的消息进行拦截，并做认证

@Slf4j
@Component
public class AuthInterceptor extends AbstractPhaseInterceptor {

	@Autowired
	private AuthorizationRepository repository;

	public AuthInterceptor() {
		super(Phase.USER_LOGICAL);
	}

	@Override
	public void handleMessage(SoapMessage message) throws Fault {
		Header header = message.getHeader(new QName("authrity"));
		if(null == header){
			log.warn("token没有认证通过!原因为：客户端请求中不存在认证的Header");
			throw new Fault(new AuthenticationException("token没有认证通过!原因为：客户端请求中不存在认证的Header"));
		}
		Element ele = (Element) header.getObject();
		if(null == ele){
			log.warn("token没有认证通过!原因为：客户端请求中认证的Header无认证信息");
			throw new Fault(new AuthenticationException("token没有认证通过!原因为：客户端请求中认证的Header无认证信息"));
		}
		Node node = ele.getFirstChild();
		if(null == node){
			log.warn("token没有认证通过!原因为：客户端请求中认证的Header无认证信息");
			throw new Fault(new AuthenticationException("token没有认证通过!原因为：客户端请求中认证的Header无认证信息"));
		}
		String token = node.getTextContent();
		if(null == token || token.isEmpty()){
			log.warn("token没有认证通过!原因为：客户端请求中认证的Header无token信息");
			throw new Fault(new AuthenticationException("token没有认证通过!原因为：客户端请求中认证的Header无token信息"));
		}
		Authorization auth = repository.findByToken(token);
		if(null == auth){
			log.warn("token没有认证通过!原因为：客户端请求中认证的token信息无效，请查看申请流程中的正确token信息");
			throw new Fault(new AuthenticationException("token没有认证通过!原因为：客户端请求中认证的token信息无效，请查看申请流程中的正确token信息，流程申请地址:http://127.0.0.1:8080/email"));
		}
		log.info("客户端认证成功，token有效!");
	}
}

注：服务端为ininterceptor

编写拦截器很简单，只需继承AbstractPhaseInterceptor类并实现handleMessage即可。

3、spring boot配置拦截器，并发布服务

@Configuration
public class WebserviceConfig {
	@Autowired
	private EmailService emailService;
	
	@Autowired
	private AuthInterceptor interceptor;
	
	@Autowired
	private ValidateInterceptor validateInterceptor;
	
	@Bean(name = Bus.DEFAULT_BUS_ID)
	public SpringBus springBus() {
		return new SpringBus();
	}

	/**
	 * attention:
	 * Details：发布WebService服务
	 * @author chhliu
	 * 创建时间：2017年5月22日 上午11:30:08
	 * @return
	 * Endpoint
	 */
	@Bean
	public Endpoint endpoint() {
		EndpointImpl endPoint = new EndpointImpl(springBus(), emailService);
		endPoint.publish("/eamil");
		endPoint.getInInterceptors().add(interceptor); // 添加Header认证拦截器
		endPoint.getInInterceptors().add(validateInterceptor);// 添加消息格式校验拦截器
		return endPoint;
	}
}

4、拦截器的Phase

Phase用来控制拦截器的工作时机，目前CXF支持的Phase如下：

public static final String SETUP = "setup";// 设置阶段
    public static final String SETUP_ENDING = "setup-ending"; // 设置完之后
    public static final String PRE_LOGICAL = "pre-logical";// 程序对象编码
    public static final String PRE_LOGICAL_ENDING = "pre-logical-ending";
    public static final String USER_LOGICAL = "user-logical";
    public static final String USER_LOGICAL_ENDING = "user-logical-ending";
    public static final String POST_LOGICAL = "post-logical";
    public static final String POST_LOGICAL_ENDING = "post-logical-ending";
    public static final String PRE_MARSHAL = "pre-marshal";
    public static final String MARSHAL = "marshal";
    public static final String POST_MARSHAL = "post-marshal";
    public static final String MARSHAL_ENDING = "marshal-ending";
    public static final String PRE_PROTOCOL = "pre-protocol";
    public static final String PRE_PROTOCOL_FRONTEND = "pre-protocol-frontend";
    public static final String PRE_PROTOCOL_ENDING = "pre-protocol-ending";
    public static final String USER_PROTOCOL = "user-protocol";
    public static final String USER_PROTOCOL_ENDING = "user-protocol-ending";
    public static final String POST_PROTOCOL = "post-protocol";
    public static final String POST_PROTOCOL_ENDING = "post-protocol-ending";
    public static final String PREPARE_SEND = "prepare-send";
    public static final String PREPARE_SEND_ENDING = "prepare-send-ending";
    public static final String PRE_STREAM = "pre-stream";
    public static final String PRE_STREAM_ENDING = "pre-stream-ending";
    public static final String USER_STREAM = "user-stream";
    public static final String USER_STREAM_ENDING = "user-stream-ending";
    public static final String POST_STREAM = "post-stream";
    public static final String POST_STREAM_ENDING = "post-stream-ending";
    public static final String WRITE = "write";
    public static final String WRITE_ENDING = "write-ending";
    public static final String SEND = "send";
    public static final String SEND_ENDING = "send-ending";
   
    public static final String RECEIVE = "receive"; // 接收阶段，传输层处理
    public static final String READ = "read";// SOAPHeader读取
    public static final String PROTOCOL = "protocol";// 协议处理阶段，例如JAX-WS的Handler处理
    public static final String PRE_UNMARSHAL = "pre-unmarshal";// SOAP请求解码之前
    public static final String UNMARSHAL = "unmarshal";// SOAP请求解码阶段
    public static final String POST_UNMARSHAL = "post-unmarshal"; // SOAP请求解码之后
    public static final String PRE_INVOKE = "pre-invoke"; // 调用业务处理之前进入该阶段
    public static final String INVOKE = "invoke"; // 调用业务阶段
    public static final String POST_INVOKE = "post-invoke";// 业务调用之后

以下是ininterceptor定义的Phase

Phase	Functions
RECEIVE	Transport level processing
(PRE/USER/POST)_STREAM	Stream level processing/transformations
READ	This is where header reading typically occurs.
(PRE/USER/POST)_PROTOCOL	Protocol processing, such as JAX-WS SOAP handlers
UNMARSHAL	Unmarshalling of the request
(PRE/USER/POST)_LOGICAL	Processing of the umarshalled request
PRE_INVOKE	Pre invocation actions
INVOKE	Invocation of the service
POST_INVOKE	Invocation of the outgoing chain if there is one

以下是outintercptor定义的Phase

On the outgoing chain there are the following phases:

Phase	Functions
SETUP	Any set up for the following phases
(PRE/USER/POST)_LOGICAL	Processing of objects about to marshalled
PREPARE_SEND	Opening of the connection
PRE_STREAM
PRE_PROTOCOL	Misc protocol actions.
WRITE	Writing of the protocol message, such as the SOAP Envelope.
MARSHAL	Marshalling of the objects
(USER/POST)_PROTOCOL	Processing of the protocol message.
(USER/POST)_STREAM	Processing of the byte level message
SEND

在SEND Phase后，有一堆以*_ENDING Phase以及与之对应的Phase，例如SEND和SEND_ENDING，这类以ENDING结尾的Phase允许清理和关闭与之对应的Phase打开或启动的任何资源。

通过上面的示例，可以发现，CXF的拦截器可以为我们实现很多的附加功能。