我有一个实现javax.servlet.Filter的类，并且在该过滤器内部，我实例化了InterceptHttpRequestFilter和InterceptHttpResponseFilter的实例（用于修改传入和传出的请求和响应）
例：
public class InterceptHttpRequestFilter implements HttpServletRequest {
private HttpServletRequest httpReq;
final StringBuffer sb = new StringBuffer();
public InterceptHttpRequestFilter(ServletRequest request) {
this.httpReq = (HttpServletRequest) request;
try {
StringWriter sw = new StringWriter();
IOUtils.copy(request.getInputStream(), sw);
sb.append(sw.getBuffer().toString());
} catch (IOException e) {
e.printStackTrace();
}
}
....
当使用Servlet 2.5在Tomcat6上部署该项目时，一切都会正常进行。
在Tomcat 7上部署它，我得到了AbstractMethodError：
SEVERE: Servlet.service() for servlet [_______] in context with path [/__________-1.0.0] threw exception [Filter execution threw an exception] with root cause
java.lang.AbstractMethodError
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:225)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at com.mycee.project.filter.MyFilter.doFilter(MyFilter.java:182)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:315)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
显而易见的解决方案是实现Servlet版本3的HttpRequest / Response接口所需的所有缺少的方法。
Maven对mvnrepository的依赖仍然在alpha中：
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>3.0-alpha-1</version>
</dependency>
所以我的问题是，是否存在使我能够在Tomcat6（Servlet 2.5）和Tomcat7（Servlet 3.0）上运行该项目的中间立场，而不必修改我的InterceptHttpRequestFilter和InterceptHttpResponseFilter？
最佳答案
这就是为什么建议扩展HttpServletRequestWrapper而不是直接实现HttpServletRequest的原因。HttpServletRequestWrapper具有所有必需方法的实现，因此应该可以解决问题。
关于java - 使Servlet 2.5代码与Servlet 3.0兼容，反之亦然，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/22323986/