RESTEasy 模拟框架在没有异常映射器的情况下工作正常——收到请求并返回带有预期内容的实体。
注册异常映射器并强制异常后,当RESTEasy内部调用ResteasyProviderFactory.getContextData(type)时调用失败,返回null,导致意外错误消息:“无法找到类型的上下文数据:javax.servlet.http.HttpServletRequest” .
在任何地方都找不到 RESTEasy 模拟和异常映射器的任何在线示例,也找不到有关该错误的任何有用信息。
客户端类:
package com.foo;
import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.XmlType;
@XmlAccessorType(XmlAccessType.FIELD)
@XmlType(name = "foo-type", propOrder = {
"name"
})
@XmlRootElement(name = "foo")
public class Foo {
protected String name;
public String getName() {
return name;
}
public void setName(String value) {
this.name = value;
}
}
对象工厂:
package com.foo;
import javax.xml.bind.annotation.XmlRegistry;
@XmlRegistry
public class ObjectFactory {
public ObjectFactory() {
}
public Foo createFoo() {
return new Foo();
}
}
验证异常:
package com.foo;
public class ValidationException extends RuntimeException {
private static final long serialVersionUID = -8100360206713223313L;
public ValidationException(String message) {
super(message);
}
public ValidationException(Exception innerException) {
super(innerException);
}
public ValidationException(String message, Exception innerException) {
super(message, innerException);
}
}
服务端点:
package com.foo;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
@Path("/rest/v1")
public class FooService {
@GET
@Path("/foo")
@Produces("application/xml")
public Foo alwaysBlowUp() throws ValidationException {
if (System.currentTimeMillis() > 0) {
throw new ValidationException("FOO");
}
return null;
}
}
异常映射器:
package com.foo;
import javax.servlet.http.HttpServletRequest;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.HttpHeaders;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.ResponseBuilder;
import javax.ws.rs.core.Response.Status;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;
@Provider
public class FooExceptionMapper implements ExceptionMapper<ValidationException> {
@Context
private static HttpServletRequest request;
@Context
private static HttpHeaders headers;
@Override
public Response toResponse(ValidationException exception) {
MediaType mediaType = null;
/*
Set breakpoint on line below.
Step over line and you get the exception in the logs.
Step into the line and the problem is in ResteasyProviderFactory:
public static <T> T getContextData(Class<T> type)
{
return (T) getContextDataMap().get(type); <<< type == javax.servlet.http.HttpServletRequest
}
The type is not in the map, so it returns null.
The null results in this error in ContextParameterInjector:
private class GenericDelegatingProxy implements InvocationHandler
{
public Object invoke(Object o, Method method, Object[] objects) throws Throwable
{
try
{
Object delegate = ResteasyProviderFactory.getContextData(type);
if (delegate == null)
throw new LoggableFailure("Unable to find contextual data of type: " + type.getName()); <<< ERROR IN LOGS
*/
String acceptHeader = request.getHeader("accept");
if (MediaType.APPLICATION_XML.equals(acceptHeader)) {
mediaType = MediaType.APPLICATION_XML_TYPE;
} else if (MediaType.APPLICATION_JSON.equals(acceptHeader)) {
mediaType = MediaType.APPLICATION_JSON_TYPE;
} else {
mediaType = headers.getMediaType();
if (mediaType == null) {
mediaType = MediaType.APPLICATION_XML_TYPE;
}
}
ResponseBuilder builder = Response.status(Status.BAD_REQUEST);
builder.type(mediaType);
return builder.build();
}
}
测试:
package com.foo;
import java.net.URISyntaxException;
import org.jboss.resteasy.core.Dispatcher;
import org.jboss.resteasy.mock.MockDispatcherFactory;
import org.jboss.resteasy.mock.MockHttpRequest;
import org.jboss.resteasy.mock.MockHttpResponse;
import org.jboss.resteasy.plugins.server.resourcefactory.POJOResourceFactory;
public final class TestFooExceptionMapper {
public static void main(String[] args) throws URISyntaxException {
Dispatcher dispatcher = MockDispatcherFactory.createDispatcher();
dispatcher.getRegistry().addResourceFactory(new POJOResourceFactory(FooService.class));
dispatcher.getProviderFactory().addExceptionMapper(FooExceptionMapper.class);
MockHttpRequest request = MockHttpRequest.get("/rest/v1/foo");
MockHttpResponse response = new MockHttpResponse();
dispatcher.invoke(request, response);
}
}
错误:
Aug 26, 2012 10:44:26 PM org.jboss.resteasy.core.SynchronousDispatcher
SEVERE: Failed executing GET /rest/v1/foo
org.jboss.resteasy.spi.LoggableFailure: Unable to find contextual data of type: javax.servlet.http.HttpServletRequest
at org.jboss.resteasy.core.ContextParameterInjector$GenericDelegatingProxy.invoke(ContextParameterInjector.java:56)
at $Proxy18.getHeader(Unknown Source)
at com.foo.FooExceptionMapper.toResponse(FooExceptionMapper.java:51)
at com.foo.FooExceptionMapper.toResponse(FooExceptionMapper.java:1)
at org.jboss.resteasy.core.SynchronousDispatcher.executeExceptionMapper(SynchronousDispatcher.java:330)
at org.jboss.resteasy.core.SynchronousDispatcher.unwrapException(SynchronousDispatcher.java:359)
at org.jboss.resteasy.core.SynchronousDispatcher.handleApplicationException(SynchronousDispatcher.java:348)
at org.jboss.resteasy.core.SynchronousDispatcher.handleException(SynchronousDispatcher.java:220)
at org.jboss.resteasy.core.SynchronousDispatcher.handleInvokerException(SynchronousDispatcher.java:196)
at org.jboss.resteasy.core.SynchronousDispatcher.getResponse(SynchronousDispatcher.java:551)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:513)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:125)
at com.foo.TestFooExceptionMapper.main(TestFooExceptionMapper.java:20)