使用CXF Interceptor特性

     在Web Service中，客戶端和服務端通過交換信息來互相通信。信息在客戶端組裝，在服務端解組。在Web Service術語中，組裝表示將JAVA對象轉換為XML文件，這些XML文檔將被傳輸到網絡中；反而言之，解組就是將XML文檔轉換為JAVA對象。

理解interceptor phase 和chain

interceptor API概覽

Interceptor接口

PhaseInterceptor接口

AbstractPhaseInterceptor抽象類

開發自定義的interceptor

public OrderProcessUserCredentialInterceptor() {
        super(Phase.PRE_INVOKE);
    }

Header header = message.getHeader(qnameCredentials);

<soap:Header>
      <OrderCredentials>
         <username>John</username>
         <password>password</password>
      </OrderCredentials>
</soap:Header>

Element elementOrderCredential = (Element) header.getObject();
Node nodeUser = elementOrderCredential.getFirstChild();
Node nodePassword = elementOrderCredential.getLastChild();
 

package demo.order.server;

import javax.xml.namespace.QName;
import org.apache.cxf.binding.soap.SoapMessage;

import org.apache.cxf.binding.soap.interceptor.AbstractSoapInterceptor;

import org.apache.cxf.headers.Header;

import org.apache.cxf.interceptor.Fault;

import org.apache.cxf.phase.Phase;

import org.w3c.dom.Element;

import org.w3c.dom.Node;
public class OrderProcessUserCredentialInterceptor extends AbstractSoapInterceptor {

private String userName;  
private String password;  

public OrderProcessUserCredentialInterceptor() {  
    super(Phase.PRE_INVOKE);  
}  

public void handleMessage(SoapMessage message) throws Fault {  

    System.out.println("OrderProcessUserCredentialInterceptor handleMessage invoked");  
    QName qnameCredentials = new QName("OrderCredentials");  

    // Get header based on QNAME  
    if (message.hasHeader(qnameCredentials)) {  
        Header header = message.getHeader(qnameCredentials);  

        Element elementOrderCredential = (Element) header.getObject();  
        Node nodeUser = elementOrderCredential.getFirstChild();  
        Node nodePassword = elementOrderCredential.getLastChild();  

        if (nodeUser != null) {  
            userName = nodeUser.getTextContent();  
        }  
        if (nodePassword != null) {  
            password = nodePassword.getTextContent();  
        }  
    }  

    System.out.println("userName reterived from SOAP Header is " + userName);  
    System.out.println("password reterived from SOAP Header is " + password);  

    // Perform dummy validation for John  
    if ("John".equalsIgnoreCase(userName) && "password".equalsIgnoreCase(password)) {  
        System.out.println("Authentication successful for John");  
    } else {  
        throw new RuntimeException("Invalid user or password");  
    }  
}  

public String getUserName() {  
    return userName;  
}  

public void setUserName(String userName) {  
    this.userName = userName;  
}  

public String getPassword() {  
    return password;  
}  

public void setPassword(String password) {  
    this.password = password;  
}  

}  </pre> 
Web Service業務類添加interceptor 

Web Service業務類可以添加配置文件或者定義annotations添加interceptor。 

添加InInterceptors注釋定義了一個Inbound interceptor，將在Web Service執行之前調用。   

@org.apache.cxf.interceptor.InInterceptors (interceptors ={"demo. order.server.OrderProcessUserCredentialInterceptor" }) 

package demo.order;

import javax.jws.WebService;
@org.apache.cxf.interceptor.InInterceptors(interceptors = {"demo.order.server.OrderProcessUserCredentialInterceptor"})

@WebService

public class OrderProcessImpl implements OrderProcess {

public String processOrder(Order order) {  
    System.out.println("Processing order...");  
    String orderID = validate(order);  
    return orderID;  
}  

/** 
 * Validates the order and returns the order ID 
* 
 */  
private String validate(Order order) {  
    String custID = order.getCustomerID();  
    String itemID = order.getItemID();  
    int qty = order.getQty();  
    double price = order.getPrice();  

    if (custID != null && itemID != null && qty > 0 && price > 0.0) {  
        return "ORD1234";  
    }  

    return null;  
}  

}  </pre> 
開發客戶端interceptor 

同樣的OrderProcessClientHandler繼承自AbstractSoapInterceptor。 

OrderProcessClientHandler默認構造器，指定了super(Phase.WRITE)，還addAfter方法。addAfter指定了OrderProcessClientHandler將在CXF內置SoapPreProtocolOutInterceptor之后添加。OrderProcessClientHandler將在Phase.WRITE并在SoapPreProtocolOutInterceptor之后運行。SoapPreProtocolOutInterceptor負責建立SOAP版本和頭，因此任何SOAP頭元素的操作都必須在SoapPreProtocolOutInterceptor之后執行。 

public OrderProcessClientHandler() {
      super(Phase.WRITE);
      addAfter(SoapPreProtocolOutInterceptor.class.getName());
}

構造函數new Header(qnameCredentials, elementCredentials);創建了Header對象，并設置了OrderCredentials元素。最后message.getHeaders().add(header)將SOAP頭添加到信息中。 

package demo.order.client;

import javax.xml.namespace.QName;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import javax.xml.parsers.ParserConfigurationException;
import org.apache.cxf.binding.soap.SoapMessage;

import org.apache.cxf.binding.soap.interceptor.AbstractSoapInterceptor;

import org.apache.cxf.binding.soap.interceptor.SoapPreProtocolOutInterceptor;

import org.apache.cxf.headers.Header;

import org.apache.cxf.interceptor.Fault;

import org.apache.cxf.phase.Phase;

import org.w3c.dom.Document;

import org.w3c.dom.Element;
public class OrderProcessClientHandler extends AbstractSoapInterceptor {

public String userName;  
public String password;  

public OrderProcessClientHandler() {  
    super(Phase.WRITE);  
    addAfter(SoapPreProtocolOutInterceptor.class.getName());  
}  

public void handleMessage(SoapMessage message) throws Fault {  

    System.out.println("OrderProcessClientHandler handleMessage invoked");  

    DocumentBuilder builder = null;  
    try {  
        builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();  
    } catch (ParserConfigurationException e) {  
        e.printStackTrace();  
    }  
    Document doc = builder.newDocument();  
    Element elementCredentials = doc.createElement("OrderCredentials");  
    Element elementUser = doc.createElement("username");  
    elementUser.setTextContent(getUserName());  
    Element elementPassword = doc.createElement("password");  
    elementPassword.setTextContent(getPassword());  
    elementCredentials.appendChild(elementUser);  
    elementCredentials.appendChild(elementPassword);  

    // Create Header object  
    QName qnameCredentials = new QName("OrderCredentials");  
    Header header = new Header(qnameCredentials, elementCredentials);  
    message.getHeaders().add(header);  
}  

public String getPassword() {  
    return password;  
}  

public void setPassword(String password) {  
    this.password = password;  
}  

public String getUserName() {  
    return userName;  
}  

public void setUserName(String userName) {  
    this.userName = userName;  
}  

}  </pre> 
客戶端添加interceptor 

OrderProcessClientHandler設置了username和password。通過ClientProxy.getClient(client);獲取Client對象，并通過cxfClient.getOutInterceptors().add(clientInterceptor)將clientInterceptor作為outbound interceptor。 

package demo.order.client;

import demo.order.OrderProcess;

import demo.order.Order;
import org.apache.cxf.frontend.ClientProxy;

import org.apache.cxf.transport.http.gzip.GZIPInInterceptor;

import org.apache.cxf.transport.http.gzip.GZIPOutInterceptor;

import org.springframework.context.support.ClassPathXmlApplicationContext;
public final class Client {

public Client() {  
}  

public static void main(String args[]) throws Exception {  
    ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"client-beans.xml"});  

    OrderProcess client = (OrderProcess) context.getBean("orderClient");  

//        OrderProcess client = (OrderProcess) context.getBean("orderClient2");

        OrderProcessClientHandler clientInterceptor = new OrderProcessClientHandler();

        clientInterceptor.setUserName("John");

        clientInterceptor.setPassword("password");

        org.apache.cxf.endpoint.Client cxfClient = ClientProxy.getClient(client);

        cxfClient.getOutInterceptors().add(clientInterceptor);

    Order order = new Order();  
    order.setCustomerID("C001");  
    order.setItemID("I001");  
    order.setQty(100);  
    order.setPrice(200.00);  

    String orderID = client.processOrder(order);  
    String message = (orderID == null) ? "Order not approved" : "Order approved; order ID is " + orderID;  
    System.out.println(message);  
}  

}  </pre> 
開發發布Web Service的服務器 

package demo.order;

import org.apache.cxf.feature.LoggingFeature;

import org.apache.cxf.interceptor.LoggingInInterceptor;

import org.apache.cxf.interceptor.LoggingOutInterceptor;

import org.apache.cxf.jaxws.JaxWsServerFactoryBean;

import org.apache.cxf.transport.http.gzip.GZIPFeature;

import org.apache.cxf.transport.http.gzip.GZIPInInterceptor;

import org.apache.cxf.transport.http.gzip.GZIPOutInterceptor;
public class OrderProcessServerStart {

public static void main(String[] args) throws Exception {  

    OrderProcess orderProcess = new OrderProcessImpl();  
    LoggingFeature log = new LoggingFeature();  
    GZIPFeature gzip = new GZIPFeature();  
    gzip.setThreshold(1);  
    JaxWsServerFactoryBean server = new JaxWsServerFactoryBean();  
    server.setServiceBean(orderProcess);  
    server.setAddress("http://localhost:8080/OrderProcess");  

    server.getFeatures().add(log);  
    server.getFeatures().add(gzip);  
    //server.getFeatures().add(log);  
    //server.getInInterceptors().add(new LoggingInInterceptor());  
    //server.getOutInterceptors().add(new LoggingOutInterceptor());  


    server.create();  
    System.out.println("Server ready....");  



    Thread.sleep(5 * 60 * 1000);  
    System.out.println("Server exiting");  
    System.exit(0);  
}  

}  </pre>  
理解CXF features 

Feature其實是interceptors另外一種形式。可以使用feature組件來代替直接使用interceptor。 

 

本例中添加了log和gzip兩個feature，正如Interceptor中所描述的phase的概念，添加log和gzip的順序會影響LoggingFeature顯示的內容。 

 

請讀者自行嘗試OrderProcessServerStart中 

 

        server.getFeatures().add(log); 

        server.getFeatures().add(gzip); 

        //server.getFeatures().add(log); 

 

和client-beans.xml中 

  
   <bean class="org.apache.cxf.feature.LoggingFeature"></bean>
   <bean class="org.apache.cxf.transport.http.gzip.GZIPFeature" >  
   <property name="threshold" value="1" /></bean>
   <!--bean class="org.apache.cxf.feature.LoggingFeature"></bean-->

          

 

安排log和gzip的添加次序。 

 

LoggingFeature 

LoggingFeature可以獨立于服務端和客戶端。也就是說，可以服務端添加LoggingFeature，而客戶端不添加，反之亦然。 

GZIPFeature 

GZIPFeature不同于LoggingFeature，客戶端和服務端必須同時實現GZIPFeature，不然會拋出異常javax.xml.ws.soap.SOAPFaultException: Couldn't parse stream.。 

 

查看添加GZIPFeature的服務器需要借助于工具。Tcpmon是其中的一個選擇，另外LoggingFeature提供了tcpmon類似的功能。 

 

在client-beans.xml中<http-conf:client>元素指定了AcceptEncoding屬性，這個屬性暗示客戶端應用將會接受gzip的內容。 

tcpmon 

如何用Apache TCPMon來截獲SOAP消息 

http://www.blogjava.net/heyang/archive/2010/12/10/340294.html 

下載地址http://ws.apache.org/commons/tcpmon/download.cgi 

  
server.setAddress("http://localhost:8080/OrderProcess");

在執行CXF過程中，是無法查看到組裝和解組的內容。如果希望看到內容，則需要借助工具。外部工具如tcpmon。將client-beans.xml address中的端口修改你希望的端口，如8081。然后在OrderProcessServerStart查看發布的端口 為8080。在tcpmon解壓的目錄bin中執行tcpmon.bat，出現tcpmon界面。切換到Admin。在Listen Port #處填寫8081，在Target Port #填寫8080，點擊Add。然后切換到Sender。為了方便查看XML，在左下角有個XML Format，將其勾選上，tcpmon會將捕獲的內容整理為XML格式。執行Client，便可以再Sender界面查看到XML的具體內容了。 

threshold 

忽略1 byte并壓縮剩下的內容。Threshold若為0值表示全部內容都將壓縮。如果Threshold未提供任何值，那么默認將執行全部內容壓縮。 

來自：http://reymont.iteye.com/blog/1532463