我正在使用CXF rest客户端,该客户端适用于简单的数据类型(例如:字符串,整数)。但是,当我尝试使用自定义对象时,得到以下信息:
Exception in thread "main" org.apache.cxf.interceptor.Fault: .No message body writer found for class : class com.company.datatype.normal.MyObject.
at org.apache.cxf.jaxrs.client.ClientProxyImpl$BodyWriter.handleMessage(ClientProxyImpl.java:523)
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:263)
at org.apache.cxf.jaxrs.client.ClientProxyImpl.doChainedInvocation(ClientProxyImpl.java:438)
at org.apache.cxf.jaxrs.client.ClientProxyImpl.invoke(ClientProxyImpl.java:177)
at $Proxy13.execute(Unknown Source)
at com.company.JaxTestClient.main(JaxTestClient.java:26)
Caused by: org.apache.cxf.jaxrs.client.ClientWebApplicationException: .No message body writer found for class : class com.company.datatype.normal.MyObject.
at org.apache.cxf.jaxrs.client.AbstractClient.reportMessageHandlerProblem(AbstractClient.java:491)
at org.apache.cxf.jaxrs.client.AbstractClient.writeBody(AbstractClient.java:401)
at org.apache.cxf.jaxrs.client.ClientProxyImpl$BodyWriter.handleMessage(ClientProxyImpl.java:515)
... 5 more
我这样称呼它:
JaxExample jaxExample = JAXRSClientFactory.create( "http://localhost:8111/", JaxExample.class );
MyObject before = ...
MyObject after = jaxExample.execute( before );
这是界面中的方法:
@POST
@Path( "execute" )
@Produces( "application/json" )
MyObject execute( MyObject myObject );
reSTLet库通过将XStream依赖项添加到您的路径中来“非常有效”,从而非常简单地做到这一点。 CXF是否类似?
编辑#1:
我将其发布为CXF问题管理系统here的功能改进。我只能希望这会得到关注。
最佳答案
它不是开箱即用的,但是CXF确实支持JSON绑定(bind)到其他服务。请参阅cxf jax-rs json docs here.。您仍然需要做一些最小的配置来使提供程序可用,并且如果您想对JSON的形成方式有更多的控制,就需要熟悉Jettison。
编辑:每个注释请求,下面是一些代码。我没有很多经验,但是以下代码在快速测试系统中作为示例。
//TestApi parts
@GET
@Path ( "test" )
@Produces ( "application/json" )
public Demo getDemo () {
Demo d = new Demo ();
d.id = 1;
d.name = "test";
return d;
}
//client config for a TestApi interface
List providers = new ArrayList ();
JSONProvider jsonProvider = new JSONProvider ();
Map<String, String> map = new HashMap<String, String> ();
map.put ( "http://www.myserviceapi.com", "myapi" );
jsonProvider.setNamespaceMap ( map );
providers.add ( jsonProvider );
TestApi proxy = JAXRSClientFactory.create ( url, TestApi.class,
providers, true );
Demo d = proxy.getDemo ();
if ( d != null ) {
System.out.println ( d.id + ":" + d.name );
}
//the Demo class
@XmlRootElement ( name = "demo", namespace = "http://www.myserviceapi.com" )
@XmlType ( name = "demo", namespace = "http://www.myserviceapi.com",
propOrder = { "name", "id" } )
@XmlAccessorType ( XmlAccessType.FIELD )
public class Demo {
public String name;
public int id;
}
笔记:
作为示例,这有点脏,但是希望可以帮助您。
编辑2:一个基于xstream以避免jaxb的消息正文编写器的示例。
@Produces ( "application/json" )
@Consumes ( "application/json" )
@Provider
public class XstreamJsonProvider implements MessageBodyReader<Object>,
MessageBodyWriter<Object> {
@Override
public boolean isWriteable ( Class<?> type, Type genericType,
Annotation[] annotations, MediaType mediaType ) {
return MediaType.APPLICATION_JSON_TYPE.equals ( mediaType )
&& type.equals ( Demo.class );
}
@Override
public long getSize ( Object t, Class<?> type, Type genericType,
Annotation[] annotations, MediaType mediaType ) {
// I'm being lazy - should compute the actual size
return -1;
}
@Override
public void writeTo ( Object t, Class<?> type, Type genericType,
Annotation[] annotations, MediaType mediaType,
MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream )
throws IOException, WebApplicationException {
// deal with thread safe use of xstream, etc.
XStream xstream = new XStream ( new JettisonMappedXmlDriver () );
xstream.setMode ( XStream.NO_REFERENCES );
// add safer encoding, error handling, etc.
xstream.toXML ( t, entityStream );
}
@Override
public boolean isReadable ( Class<?> type, Type genericType,
Annotation[] annotations, MediaType mediaType ) {
return MediaType.APPLICATION_JSON_TYPE.equals ( mediaType )
&& type.equals ( Demo.class );
}
@Override
public Object readFrom ( Class<Object> type, Type genericType,
Annotation[] annotations, MediaType mediaType,
MultivaluedMap<String, String> httpHeaders, InputStream entityStream )
throws IOException, WebApplicationException {
// add error handling, etc.
XStream xstream = new XStream ( new JettisonMappedXmlDriver () );
return xstream.fromXML ( entityStream );
}
}
//now your client just needs this
List providers = new ArrayList ();
XstreamJsonProvider jsonProvider = new XstreamJsonProvider ();
providers.add ( jsonProvider );
TestApi proxy = JAXRSClientFactory.create ( url, TestApi.class,
providers, true );
Demo d = proxy.getDemo ();
if ( d != null ) {
System.out.println ( d.id + ":" + d.name );
}
该示例代码缺少用于可靠的媒体类型支持,错误处理,线程安全性等的部分。但是,它应该以最少的代码解决jaxb问题。
编辑3-示例服务器端配置
如前所述,我的服务器端是spring配置的。这是一个示例配置,可用于连接提供程序:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:jaxrs="http://cxf.apache.org/jaxrs"
xmlns:cxf="http://cxf.apache.org/core"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://cxf.apache.org/jaxrs http://cxf.apache.org/schemas/jaxrs.xsd
http://cxf.apache.org/core http://cxf.apache.org/schemas/core.xsd">
<import resource="classpath:META-INF/cxf/cxf.xml" />
<jaxrs:server id="TestApi">
<jaxrs:serviceBeans>
<ref bean="testApi" />
</jaxrs:serviceBeans>
<jaxrs:providers>
<bean id="xstreamJsonProvider" class="webtests.rest.XstreamJsonProvider" />
</jaxrs:providers>
</jaxrs:server>
<bean id="testApi" class="webtests.rest.TestApi">
</bean>
</beans>
我还注意到,在我使用的最新版本的cxf中,媒体类型有所不同,因此,上面xstream消息正文阅读器/编写器上的示例需要对isWritable/isReadable进行快速修改,以将其更改为:
return MediaType.APPLICATION_JSON_TYPE.getType ().equals ( mediaType.getType () )
&& MediaType.APPLICATION_JSON_TYPE.getSubtype ().equals ( mediaType.getSubtype () )
&& type.equals ( Demo.class );
编辑4-非spring配置
使用您选择的servlet容器,进行配置
org.apache.cxf.jaxrs.servlet.CXFNonSpringJaxrsServlet
至少有2个初始化参数:
jaxrs.serviceClasses
jaxrs.providers
其中,serviceClasses是要绑定(bind)的服务实现的空格分隔列表,例如上面提到的TestApi,provider是消息主体提供程序的空格分隔列表,例如上面提到的XstreamJsonProvider。在tomcat中,您可以将以下内容添加到web.xml:
<servlet>
<servlet-name>cxfservlet</servlet-name>
<servlet-class>org.apache.cxf.jaxrs.servlet.CXFNonSpringJaxrsServlet</servlet-class>
<init-param>
<param-name>jaxrs.serviceClasses</param-name>
<param-value>webtests.rest.TestApi</param-value>
</init-param>
<init-param>
<param-name>jaxrs.providers</param-name>
<param-value>webtests.rest.XstreamJsonProvider</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
这几乎是没有 Spring 即可运行的最快方法。如果不使用servlet容器,则需要使用XstreamJsonProvider的实例配置JAXRSServerFactoryBean.setProviders,并通过JAXRSServerFactoryBean.setResourceProvider方法设置服务实现。检查CXFNonSpringJaxrsServlet.init方法以查看在servlet容器中设置时它们如何执行。
无论您遇到什么情况,这都应该使您能够前进。
关于java - CXF:找不到类的消息正文编写器-自动映射非简单资源,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/6312030/