当我在谷歌上搜索“servlet filter with jax-rs example”时,
this排在榜首。从代码的粗略扫描中,我认为这符合我的需求。
这是我的解决方案(到目前为止...请参见脚注警告)
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
<filter>
<filter-name>accept-filter</filter-name>
<filter-class>com.extratechnology.filters.AcceptFilter</filter-class>
<init-param>
<param-name>xml</param-name>
<param-value>text/xml</param-value>
</init-param>
<init-param>
<param-name>json</param-name>
<param-value>application/json</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>accept-filter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<servlet>
<servlet-name>Jersey Web Application</servlet-name>
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>jersey.config.server.provider.packages</param-name>
<param-value>com.extratechnology.caaews</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Jersey Web Application</servlet-name>
<url-pattern>/webapi/*</url-pattern>
</servlet-mapping>
</web-app>
AcceptFilter.java
package com.extratechnology.filters;
import java.io.IOException;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class AcceptFilter implements Filter {
private final Map<String,String> extensions = new HashMap<String,String>();
public void init(FilterConfig config) throws ServletException {
Enumeration<String> exts = config.getInitParameterNames();
while (exts.hasMoreElements()) {
String ext = exts.nextElement();
if (ext != null && !ext.isEmpty()) {
this.extensions.put(ext.toLowerCase(), config.getInitParameter(ext));
}
}
}
public void destroy() {}
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
HttpServletRequest httpRequest = (HttpServletRequest)request;
String uri = httpRequest.getRequestURI();
String ext = this.getExtension(uri);
String accept = this.extensions.get(ext);
if (accept == null) {
accept = httpRequest.getHeader("accept");
if (accept != null && accept.indexOf("text/html") > 0) {
accept = "text/html,"+accept;
request = new RequestWrapper(httpRequest, uri, accept);
}
} else {
uri = uri.substring(0, uri.length() - ext.length()-1);
request = new RequestWrapper(httpRequest, uri, accept);
}
HttpServletResponse httpResponse = (HttpServletResponse)response;
httpResponse.addHeader("Vary", "accept");
chain.doFilter(request, response);
}
private String getExtension(String path) {
String result = "";
int index = path.lastIndexOf('.');
if (!(index < 0 || path.lastIndexOf('/') > index)) {
result = path.substring(index+1).toLowerCase();
}
return result;
}
private static class RequestWrapper extends HttpServletRequestWrapper {
private final String uri;
private final String accept;
public RequestWrapper(HttpServletRequest request, String uri, String accept) {
super(request);
this.uri = uri;
this.accept = accept;
}
@Override
public String getRequestURI() {
return this.uri;
}
@Override
public Enumeration<String> getHeaders(String name) {
Enumeration<String> result;
if ("accept".equalsIgnoreCase(name)) {
Vector<String> values = new Vector<String>(1);
values.add(this.accept);
result = values.elements();
} else {
result = super.getHeaders(name);
}
return result;
}
}
}
CAAEWS.java
package com.extratechnology.caaews;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import com.extratechnology.caaews.model.Log;
@Path("et")
@Produces(value = {MediaType.APPLICATION_JSON, MediaType.TEXT_XML})
public class CAAEWS {
@GET
@Produces(MediaType.APPLICATION_JSON)
public Log getJSON() {
return new Log("JSON!");
}
@GET
@Produces(MediaType.TEXT_XML)
public Log getXML() {
return new Log("XML!");
}
}
Log.java
package com.extratechnology.caaews.model;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement
public class Log {
private String log;
public Log(String log) {
this.log = log;
}
public String getLog() {
return log;
}
public void setLog(String log) {
this.log = log;
}
}
唯一让我稍感兴趣的是HTTP有两种XML内容类型。
这可以在web.xml中进行配置,但我需要调整注释。为什么会有两个呢?
--
注释:
写完这段代码后,我发现我现在遇到了HTTP 500错误。
当你在Eclipse中运行服务器时,日志似乎存储在某个隐蔽的文件夹中:
Documents\workspace-sts-3.8.3.RELEASE\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\logs
然后我将这个写入日志:
0:0:0:0:0:0:0:1 - - [25/Nov/2017:16:56:00 +0000] "GET /caaews/webapi/et.xml HTTP/1.1" 500 1082
有人知道如何获取更有意义的日志信息吗?或者我需要做什么来捕获更有意义的堆栈跟踪?
看起来 Log 类需要一个无参构造函数来解决这个问题。但我承认,@peeskillet 的答案更简单,并且使用了内置的 Jersey 功能。
我也在想,如果查看 这里 的示例后,javax.servlet.filters 是否与 JAX-RS 2.0 不兼容...
根据此问题的其他相关答案/评论,我最终实现了一个异常处理程序,以便在Jersey中获取有关HTTP 500消息的更多信息。
以下是帮助指向需要无参数构造函数的Log.java的代码。
错误消息
package com.extratechnology.caaews.model;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement
public class ErrorMessage {
private String errorMessage;
private String errorStackTrace;
private String cause;
private String causeStackTrace;
private int errorCode;
public ErrorMessage() {
}
public ErrorMessage(
String errorMessage,
String errorStackTrace,
String cause,
String causeStackTrace,
int errorCode
) {
this.errorMessage = errorMessage;
this.errorStackTrace = errorStackTrace;
this.cause = cause;
this.causeStackTrace = causeStackTrace;
this.errorCode = errorCode;
}
public String getErrorMessage() {
return errorMessage;
}
public void setErrorMessage(String errorMessage) {
this.errorMessage = errorMessage;
}
public String getErrorStackTrace() {
return errorStackTrace;
}
public void setErrorStackTrace(String errorStackTrace) {
this.errorStackTrace = errorStackTrace;
}
public String getCause() {
return cause;
}
public void setCause(String cause) {
this.cause = cause;
}
public String getCauseStackTrace() {
return causeStackTrace;
}
public void setCauseStackTrace(String causeStackTrace) {
this.causeStackTrace = causeStackTrace;
}
public int getErrorCode() {
return errorCode;
}
public void setErrorCode(int errorCode) {
this.errorCode = errorCode;
}
}
GenericExceptionMapper.java
package com.extratechnology.caaews.exception;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;
import javax.ws.rs.ext.ExceptionMapper;
import javax.ws.rs.ext.Provider;
import com.extratechnology.caaews.model.ErrorMessage;
@Provider
public class GenericExceptionMapper implements ExceptionMapper<Throwable>{
@Override
public Response toResponse(Throwable ex) {
System.out.println("Stack Trace:");
ex.printStackTrace();
System.out.println("Cause:");
Throwable cause = ex.getCause();
if (cause != null) {
cause.printStackTrace();
}
ErrorMessage message = new ErrorMessage(
ex.getMessage(),
GenericExceptionMapper.getStackTrack(ex),
cause.getMessage(),
GenericExceptionMapper.getStackTrack(cause),
Status.INTERNAL_SERVER_ERROR.getStatusCode()
);
return Response
.status(Status.INTERNAL_SERVER_ERROR)
.entity(message)
.build();
}
private static String getStackTrack(Throwable ex) {
StringBuilder sb = new StringBuilder();
String ls = System.lineSeparator();
if (ex != null) {
StackTraceElement[] steAll = ex.getStackTrace();
for (StackTraceElement ste : steAll) {
sb.append(ste.toString());
sb.append(ls);
}
}
return sb.toString();
}
}
在调试时,system.out.println会在控制台输出消息,并且在出现错误时,您还可以在Web浏览器中获得有效载荷。
例如:
This XML file does not appear to have any style information associated with it. The document tree is shown below.
<errorMessage>
<cause>1 counts of IllegalAnnotationExceptions</cause>
<causeStackTrace>
com.sun.xml.internal.bind.v2.runtime.IllegalAnnotationsException$Builder.check(Unknown Source) com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.getTypeInfoSet(Unknown Source) com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.<init>(Unknown Source) com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.<init>(Unknown Source) com.sun.xml.internal.bind.v2.runtime.JAXBContextImpl$JAXBContextBuilder.build(Unknown Source) com.sun.xml.internal.bind.v2.ContextFactory.createContext(Unknown Source) sun.reflect.GeneratedMethodAccessor20.invoke(Unknown Source) sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) java.lang.reflect.Method.invoke(Unknown Source) javax.xml.bind.ContextFinder.newInstance(Unknown Source) javax.xml.bind.ContextFinder.newInstance(Unknown Source) javax.xml.bind.ContextFinder.find(Unknown Source) javax.xml.bind.JAXBContext.newInstance(Unknown Source) javax.xml.bind.JAXBContext.newInstance(Unknown Source) org.glassfish.jersey.jaxb.internal.AbstractJaxbProvider.getStoredJaxbContext(AbstractJaxbProvider.java:312) org.glassfish.jersey.jaxb.internal.AbstractJaxbProvider.getJAXBContext(AbstractJaxbProvider.java:297) org.glassfish.jersey.jaxb.internal.AbstractJaxbProvider.getMarshaller(AbstractJaxbProvider.java:264) org.glassfish.jersey.jaxb.internal.AbstractJaxbProvider.getMarshaller(AbstractJaxbProvider.java:231) org.glassfish.jersey.jaxb.internal.AbstractRootElementJaxbProvider.writeTo(AbstractRootElementJaxbProvider.java:175) org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.invokeWriteTo(WriterInterceptorExecutor.java:266) org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:251) org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:163) org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:109) org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:163) org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:85) org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:163) org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1135) org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:662) org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:395) org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:385) org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:280) org.glassfish.jersey.internal.Errors$1.call(Errors.java:272) org.glassfish.jersey.internal.Errors$1.call(Errors.java:268) org.glassfish.jersey.internal.Errors.process(Errors.java:316) org.glassfish.jersey.internal.Errors.process(Errors.java:298) org.glassfish.jersey.internal.Errors.process(Errors.java:268) org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:289) org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:256) org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:703) org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:416) org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:370) org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:389) org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:342) org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:229) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:217) org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456) java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) java.lang.Thread.run(Unknown Source)
</causeStackTrace>
<errorCode>500</errorCode>
<errorMessage>HTTP 500 Internal Server Error</errorMessage>
<errorStackTrace>
org.glassfish.jersey.jaxb.internal.AbstractRootElementJaxbProvider.writeTo(AbstractRootElementJaxbProvider.java:183) org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.invokeWriteTo(WriterInterceptorExecutor.java:266) org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:251) org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:163) org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:109) org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:163) org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:85) org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:163) org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1135) org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:662) org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:395) org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:385) org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:280) org.glassfish.jersey.internal.Errors$1.call(Errors.java:272) org.glassfish.jersey.internal.Errors$1.call(Errors.java:268) org.glassfish.jersey.internal.Errors.process(Errors.java:316) org.glassfish.jersey.internal.Errors.process(Errors.java:298) org.glassfish.jersey.internal.Errors.process(Errors.java:268) org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:289) org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:256) org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:703) org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:416) org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:370) org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:389) org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:342) org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:229) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:217) org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502) org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616) org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:518) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1091) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:673) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500) org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456) java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) java.lang.Thread.run(Unknown Source)
</errorStackTrace>
</errorMessage>
def add_numbers(x, y): return x + y print(add_numbers(5, 10))
我的翻译:请提供一个输入示例和您的尝试。请参见[mcve]。本网站不提供编码服务。 - user1803551break
语句的case
语句。启用标准的Java编译器警告并遵守它们,您就不会再犯这种错误了。 - VGR