1．使用Axis2的底层API开发Web Service Server端
1.1创建一个WebService(取名为MyService)
在MyService中有两个operations,如下所示。
public void ping(OMElement element){}//IN-ONLY模式。仅仅接收OMElement，并对其处理。
public OMElement echo(OMElement element){}//IN_OUT模式。接收OMElemen，并返回OMElement。
1.2如何写Web Service
1）创建实现服务的类。
2）创建services.xml来解析这个Web Service。
3）将其打包成一个*.aar文档（Axis Archive）。
4）部署Web Service。
1.2.1 创建实现服务的类
此类中提供的方法必须与Web Service（在services.xml中声明）中的operations对应。除非你提供了数据绑定，否则所有的方法只能接收一个参数，其类型为OMElement。
public class MyService{
public void ping(OMElement element){...}
public OMElement echo(OMElement element){...}
}
MyService.java
package userguide.example1;
import org.apache.axiom.om.OMElement;
import org.apache.axis2.AxisFault;
import javax.xml.stream.XMLStreamException;
public class MyService {
public OMElement echo(OMElement element) throws XMLStreamException {
//Praparing the OMElement so that it can be attached to another OM Tree.
//First the OMElement should be completely build in case it is not fully built and still
//some of the xml is in the stream.
element.build();
//Secondly the OMElement should be detached from the current OMTree so that it can
// be attached some other OM Tree. Once detached the OmTree will remove its
// connections to this OMElement.
element.detach();
return element;
}
public void ping(OMElement element) throws XMLStreamException {
//Do some processing
}
public void pingF(OMElement element) throws AxisFault{
throw new AxisFault("Fault being thrown");
}
}
1.2.2 创建services.xml
Axis2使用services.xml来充当一个Web Servicea的配置文件。每一个使用Axis2部署的Web Service都必须拥有一个services.xml。
<services>
<description>
This is a sample Web Service with two operations,echo and ping.
</description>
<parameter name=”ServiceClass” locked=”false”>
userguide.example1.MyService
</parameter>
<operation name=”echo”>
<messageReceiver class=”org.apache.axis2.receivers.RawXMLINOutMessageReceiver”/>
<actionMapping>urn:echo</actionMapping>
</operation>
<operation name=”ping”>
<messageReceiver class=”org.apache.receivers.RawXMLINOnlyMessageReceiver”/>
<actionMapping>urn:ping</actionMapping>
</operation>
</service>
注：The actionMapping is required only if you want to enable WS-Addressing.
可以创建一个services.xml，其中包含一组服务。这样在运行期，你可以在这些服务间共享信息。
<serviceGroup>
<service name=”Service1”>
<!--details for Services1-->
</service>
<service name=”Service2”>
<!--details for Services2-->
</service>
<module ref=”ModuleName”/>
<parameter name=”serviceGroupParam1” locked=”false”>value1</parameter>
</serviceGroup>
注：name of the service is a compulsory attribute.
2．使用Axis2底层APIs实现Web Service客户端
2.1ClientUtil
创建一个客户端通用的SOAP包装Util文件。封装"getEchoOMElement"和"getPingOMElement"分别对应"echo"和"ping"这两个operation。
ClientUtil.java
package userguide.clients;
import org.apache.axiom.om.OMAbstractFactory;
import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMFactory;
import org.apache.axiom.om.OMNamespace;
public class ClientUtil {
public static OMElement getEchoOMElement() {
OMFactory fac = OMAbstractFactory.getOMFactory();
OMNamespace omNs = fac.createOMNamespace(
"http://example1.org/example1", "example1");
OMElement method = fac.createOMElement("echo", omNs);
OMElement value = fac.createOMElement("Text", omNs);
value.addChild(fac.createOMText(value, "Axis2 Echo String "));
method.addChild(value);
return method;
}
public static OMElement getPingOMElement() {
OMFactory fac = OMAbstractFactory.getOMFactory();
OMNamespace omNs = fac.createOMNamespace(
"http://example1.org/example1", "example1");
OMElement method = fac.createOMElement("ping", omNs);
OMElement value = fac.createOMElement("Text", omNs);
value.addChild(fac.createOMText(value, "Axis2 Ping String "));
method.addChild(value);
return method;
}
}
2.2EchoBlockingClient
Axis2向用户提供了从blocking
single channel调用到non-blocking dual channel调用的多种调用Web
Service的模式。下面用最简单的blocking调用机制来实现”MyService”中的"echo" operation。
EchoBlockingClient.java
package userguide.clients;
import org.apache.axiom.om.OMElement;
import org.apache.axis2.AxisFault;
import org.apache.axis2.addressing.EndpointReference;
import org.apache.axis2.client.Options;
import org.apache.axis2.client.ServiceClient;
/**
* Sample for synchronous single channel blocking service invocation.
* Message Exchage Pattern IN-OUT
*/
public class EchoBlockingClient {
private static EndpointReference targetEPR =
new EndpointReference("http://localhost:8080/axis2/services/MyService");
public static void main(String[] args) {
try {
OMElement payload = ClientUtil.getEchoOMElement();
Options options = new Options();
options.setTo(targetEPR); // this sets the location of MyService service
ServiceClient serviceClient = new ServiceClient();
serviceClient.setOptions(options);
OMElement result = sender.sendReceive(payload);
System.out.println(result);
} catch (AxisFault axisFault) {
axisFault.printStackTrace();
}
}
绿色部分显示了为了调用一个Web Service而需要对operation作的设置。剩下的部分是用来创建OMElement，用来发送和显示相应的OMElement。
结果：
2.3 PingClient
在”MyService”中，我们有一种IN-ONLY模式的名为"ping"的operation。应用它的客户端代码如下：
PingClient.java
package userguide.clients;
import org.apache.axiom.om.OMElement;
import org.apache.axis2.AxisFault;
import org.apache.axis2.addressing.EndpointReference;
import org.apache.axis2.client.Options;
import org.apache.axis2.client.ServiceClient;
/**
* Sample for fire-and-forget service invocation
* Message Exchage Pattern IN-Only
*/
public class PingClient {
private static EndpointReference targetEPR =
new EndpointReference("http://localhost:8080/axis2/services/MyService");
public static void main(String[] args) {
try {
OMElement payload = ClientUtil.getPingOMElement();
Options options = new Options();
options.setTo(targetEPR);
ServiceClient serviceClient = new ServiceClient();
serviceClient.setOptions(options);
serviceClient.fireAndForget(payload);
/**
* We have to block this thread untill we send the request , the problem
* is if we go out of the main thread , then request wont send ,so
* you have to wait some time :)
*/
Thread.sleep(500);
}
catch (AxisFault axisFault) {
axisFault.printStackTrace();
}
}
由于我们在访问一个IN-ONLY模式的operation，所以我们可以直接使用ServiceClient中的"fireAndForget()"方法来调用这个operation。而且那样做的话，不会阻塞发起端，因此，它会立刻将控制权返回给客户端。
2.4 EchoNonBlockingClient
在客户端EchoBlockingClient，一旦调用"serviceClient.sendReceive(payload);"，客户端将会被阻
塞直到operation完成。这种方式在有很多Web
Service需要在一个单一的客户端应用程序中启动时很不可取。一种解决方法是使用Non-Blocking API来调用这些Web
Services。Axis2提供给用户一种基于回叫机制的non-blocking API。
EchoNonBlockingClient.java
package userguide.clients;
import org.apache.axiom.om.OMElement;
import org.apache.axis2.AxisFault;
import org.apache.axis2.addressing.EndpointReference;
import org.apache.axis2.client.Options;
import org.apache.axis2.client.ServiceClient;
import org.apache.axis2.client.async.AsyncResult;
import org.apache.axis2.client.async.Callback;
/**
* Sample for asynchronous single channel non-blocking service invocation.
* Message Exchage Pattern IN-OUT
*/
public class EchoNonBlockingClient {
private static EndpointReference targetEPR =
new EndpointReference("http://127.0.0.1:8080/axis2/services/MyService");
public static void main(String[] args) {
ServiceClient sender = null;
try {
OMElement payload = ClientUtil.getEchoOMElement();
Options options = new Options();
options.setTo(targetEPR);
//Callback to handle the response
Callback callback = new Callback() {
public void onComplete(AsyncResult result) {
System.out.println(result.getResponseEnvelope());
}
public void onError(Exception e) {
e.printStackTrace();
}
};
//Non-Blocking Invocation
sender = new ServiceClient();
sender.setOptions(options);
sender.sendReceiveNonBlocking(payload, callback);
//Wait till the callback receives the response.
while (!callback.isComplete()) {
Thread.sleep(1000);
}
} catch (AxisFault axisFault) {
axisFault.printStackTrace();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
try {
sender.finalizeInvoke();
} catch (AxisFault axisFault) { }
}
}
}
结果：
sender.sendReceiveNonBlocking(payload, callback);这个调用接受一个callback对象作为参数。Axis2客户端API提供了一个抽象类CallBack，其中提供了方法：
public abstract void onComplete(AsyncResult result);
public abstract void onError(Exception e);
public boolean isComplete() {}
用户需要重写"onComplete " 和 "onError "方法。一旦客户端收到Web Service的response，onComplete方法将会被调用，这样将中止阻塞状态。
2.5EchoNonBlockingDualClient
当调用的Web
Service需要很长一段时间来完成时，这种由Non-Blocking
API提供的解决方式将有一定的局限性。这种局限性是由使用单一的传输连接来调用Web
Service并接收response造成的。换句话说，客户端提供一种没有阻塞的调用机制，但request和response的传输使用单一的传输
（双工方式）连接（如HTTP）。长时间运行的Web Service调用或Web
Service调用使用单工传输方式（如SMTP）不能简单地利用一个没有阻塞的调用。
一种尝试地解决方法是request和response各自使用单独的传输连接（单工或双工均可）。这种方式产生的问题是如何解决相关性（关联
request和response）。WS-Addressing提供了一种很好的解决方法，在头中使用<wsa:MessageID>
和 <wsa:RelatesTo> 标签。Axis2对这种基于关联机制的寻址方式提供了支持。
用户可以选择Blocking 或Non-Blocking APIs的Web
Service，并使用两个传输连接。通过使用一个布尔标记，同一个API可以调用多个在两个传输连接上的Web Services(IN-OUT
operations)。下例使用Non-Blocking API 以及两个传输连接来实现上文中提到的"echo" operation。
EchoNonBlockingDualClient.java
package userguide.clients;
import org.apache.axiom.om.OMElement;
import org.apache.axis2.AxisFault;
import org.apache.axis2.Constants;
import org.apache.axis2.addressing.EndpointReference;
import org.apache.axis2.client.Options;
import org.apache.axis2.client.ServiceClient;
import org.apache.axis2.client.async.AsyncResult;
import org.apache.axis2.client.async.Callback;
import javax.xml.namespace.QName;
/**
* Sample for asynchronous dual channel non-blocking service invocation.
* Message Exchage Pattern IN-OUT
* Ulitmate asynchronous service invocation sample.
*/
public class EchoNonBlockingDualClient {
private static EndpointReference targetEPR =
new EndpointReference("http://127.0.0.1:8080/axis2/services/MyService");
public static void main(String[] args) {
ServiceClient sender = null;
try {
OMElement payload = ClientUtil.getEchoOMElement();
Options options = new Options();
options.setTo(targetEPR);
options.setTransportInProtocol(Constants.TRANSPORT_HTTP);
options.setUseSeparateListener(true);
options.setAction("urn:echo"); // this is the action mapping we put within the service.xml
//Callback to handle the response
Callback callback = new Callback() {
public void onComplete(AsyncResult result) {
System.out.println(result.getResponseEnvelope());
}
public void onError(Exception e) {
e.printStackTrace();
}
};
//Non-Blocking Invocation
ConfigurationContext sysContext = ConfigurationContextFactory
.createConfigurationContextFromFileSystem(
"D:\\Dvp\\Axis2\\axis2\\WEB-INF", null);//见注解①
sender = new ServiceClient(sysContext, null);
sender.engageModule(new QName(Constants.MODULE_ADDRESSING));
sender.setOptions(options);
sender.sendReceiveNonBlocking(payload, callback);
//Wait till the callback receives the response.
while (!callback.isComplete()) {
Thread.sleep(1000);
}
//Need to close the Client Side Listener.
} catch (AxisFault axisFault) {
axisFault.printStackTrace();
} catch (Exception ex) {
ex.printStackTrace();
} finally {
try {
sender.finalizeInvoke();
} catch (AxisFault axisFault) {
//have to ignore this
}
}
}
}
注解①
RE: [Axis2] 0.95 WS-Addressing web SERVICE-SIDE: module not found
I now have managed to get EchoNonBlockingDualClient working. I still
can't get the original code to work, where ever I put
addressing-0.95.mar, but the ConfigurationContext works.
The code I ended up with was:
ConfigurationContext sysContext = ConfigurationContextFactory
.createConfigurationContextFromFileSystem(
"C:\\axis2", null);
sender = new ServiceClient(sysContext, null);
with no need, obviously, for the .engageModule method.
I did discover though that the directory which the ConfigurationContext
points to has to have two directories within it: "conf", which must
contain the axis.xml configuration file, and the "modules" directory
which contains addressing-0.95.mar.
在方法"options.setUseSeparateListener(...)"中的布尔标记通知通知Axis2引擎使用两个不同的传输连接来分别处
理request和response。Finally中的
"serviceClient.finalizeInvoke()"方法通知Axis2引擎停用客户端的用于接收response的listener。
在我们运行客户端的例程之前，我们还有一件事情要做。如前面提到的，Axis2使用基于地址的关联机制，因此我们必须在服务器端和客户端“搭建”寻址模块。
结果：
[SimpleHTTPServer] Stop called
2.6 实现服务器端的寻址
根据Axis2的结构，寻址模块在"pre-dispatch"阶段已经给出它的句柄。因此，所谓的“搭建”仅仅是在”axis2.xml”（注意不是
services.xml）增加一个模块的引用。现在将下面这行字加入到axis2.xml，该文件在"/webapps/axis2/WEB-
INF/conf"目录下。
<module ref="addressing"/>
注： 一旦你改变了axis2.xml，你必须重启这个servlet容器，改变才能生效。
2.7 实现客户端的寻址
有两种方式。
一种方法是在%Axis2_HOME%\axis2-std-1.0-bin\modules目录下得到addressing-<
version>.mar。并且在你的classpath中对其可见。（此种方法目前，我还没有调试成功，具体见注解①。下面的第二种方法可用）
另一种方法是创建一个ConfigurationContext，指定一个repository位置。Axis2支持repository的方式来保存服务和模块。
你可以使用二进制distribution作为repository，只要它含有一个Axis2
repository认可的repository结构（其中应包含services和modules目录）。ConfigurationContext
中含有Axis2体系的运行时的上下文信息。
如果你解压一个标准的二进制distribution到目录（譬如）$user_home/axis2/dist, 那么在 sender = new
ServiceClient();之前加入（具体见EchoNonBlockingDualClient.java）：
new ServiceClient();之前加入（具体见EchoNonBlockingDualClient.java）：
ConfigurationContext configContext =
ConfigurationContextFactory.createConfigurationContextFromFileSystem(< Axis2RepositoryLocation >, null);
用"sender = new ServiceClient(configContext, null);" 替换 "sender = new ServiceClient();"
这样可以在客户端和服务器端都实现寻址。
2.8 EchoBlockingDualClient
这又是一个两路的传输的request/response客户端，但这次，我们使用一个Blocking
API。实现机制和EchoNonBlockingDualClient差不多，唯一的不同是，这里不需要使用一个callback对象来处理
response。
EchoBlockingDualClient.java
package userguide.clients;
import org.apache.axiom.om.OMElement;
import org.apache.axis2.AxisFault;
import org.apache.axis2.Constants;
import org.apache.axis2.addressing.EndpointReference;
import org.apache.axis2.client.Options;
import org.apache.axis2.client.ServiceClient;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLOutputFactory;
import java.io.StringWriter;
/**
* Sample for synchronous dual channel blocking service invocation.
* Message Exchage Pattern IN-OUT
*/
public class EchoBlockingDualClient {
private static EndpointReference targetEPR =
new EndpointReference("http://127.0.0.1:8080/axis2/services/MyService");
public static void main(String[] args) {
ServiceClient sender = null;
try {
OMElement payload = ClientUtil.getEchoOMElement();
Options options = new Options();
options.setTo(targetEPR);
options.setAction("urn:echo");
//The boolean flag informs the axis2 engine to use two separate transport connection
//to retrieve the response.
options.setTransportInProtocol(Constants.TRANSPORT_HTTP);
options.setUseSeparateListener(true);
//Blocking Invocation
ConfigurationContext sysContext = ConfigurationContextFactory
.createConfigurationContextFromFileSystem(
"D:\\Dvp\\Axis2\\axis2\\WEB-INF", null);
sender = new ServiceClient(sysContext, null);
sender.engageModule(new QName(Constants.MODULE_ADDRESSING));
sender.setOptions(options);
OMElement result = sender.sendReceive(payload);
StringWriter writer = new StringWriter();
result.serialize(XMLOutputFactory.newInstance().createXMLStreamWriter(writer));
writer.flush();
System.out.println(writer.toString());
//Need to close the Client Side Listener.
} catch (AxisFault axisFault) {
axisFault.printStackTrace();
} catch (Exception ex) {
ex.printStackTrace();
} finally{
try {
sender.finalizeInvoke();
} catch (AxisFault axisFault) {
//
}
}
}
}
结果：
<example1:echo xmlns:example1="http://example1.org/example1" xmlns:tns="http://ws.apache.org/axis2">
<example1:Text>Axis2 Echo String </example1:Text>
</example1:echo>
[SimpleHTTPServer] Stop called