摘要：
Servlet3.0作为J2EE 6规范一部分，并随J2EE6一起发布，WeFilter是过滤器注解，是Servlet3.0的新特性，不需要在web.xml进行配置，简化了配置。
| Name | Type | Required | Description |
| filterName | String | Optional | Name of the filter. |
| value or urlPatterns | String[] | Required | Specify one or more URL patterns to which the filter applies. Either of attribute can be used, but not both. |
| dispatcherTypes | DispatcherType[] | Optional | Specify types of dispatcher to which the filter applies. Default isjavax.servlet.DispatcherType.REQUEST |
| servletNames | String[] | Optional | Specify names of servlets to which the filter applies. |
| displayName | String | Optional | Display name of the filter. |
| description | String | Optional | Description of the filter. |
| asyncSupported | boolean | Optional | Specify whether the filter supports asynchronous operation mode. Default is false. |
| initParams | WebInitParam[] | Optional | Specify one or more initialization parameters of the filter. Each parameter is specified by@WebInitParamannotation type. |
| smallIcon | String | Optional | Specify name of the small icon of the filter. |
| largeIcon | String | Optional | Specify name of the large icon of the filter. |
OneFilter：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | package com.what21.servlet.webfilter; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.annotation.WebFilter; @WebFilter ( "/*" ) public class OneFilter implements Filter { @Override public void init(FilterConfig config) throws ServletException { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { System.out.println( "OneFilter doFilter()" ); chain.doFilter(request, response); } @Override public void destroy() { } } |
TwoFilter：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | package com.what21.servlet.webfilter; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.annotation.WebFilter; @WebFilter (servletNames = "MyFourServlet" ) public class TwoFilter implements Filter { @Override public void init(FilterConfig config) throws ServletException { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { System.out.println( "TwoFilter doFilter()" ); chain.doFilter(request, response); } @Override public void destroy() { } } |
ThreeFilter：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | package com.what21.servlet.webfilter; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.annotation.WebFilter; @WebFilter (servletNames = { "MyFourServlet" , "MyFiveServlet" }) public class ThreeFilter implements Filter { @Override public void init(FilterConfig config) throws ServletException { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { System.out.println( "ThreeFilter doFilter()" ); chain.doFilter(request, response); } @Override public void destroy() { } } |
FourFilter：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 | package com.what21.servlet.webfilter; import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.annotation.WebFilter; @WebFilter ({ "/one" , "/two" }) public class FourFilter implements Filter { @Override public void init(FilterConfig config) throws ServletException { } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { System.out.println( "FourFilter doFilter()" ); chain.doFilter(request, response); } @Override public void destroy() { } } |
FiveFilter：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 | package com.what21.servlet.webfilter; import java.io.IOException; import javax.servlet.DispatcherType; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.annotation.WebFilter; import javax.servlet.annotation.WebInitParam; @WebFilter ( urlPatterns = "/five" , filterName = "FiveFilter" , initParams = { @WebInitParam (name = "name" , value = "username" ), @WebInitParam (name = "value" , value = "password" ) }, description = "MyFiveFilter" , dispatcherTypes = {DispatcherType.REQUEST, DispatcherType.FORWARD} ) public class FiveFilter implements Filter { @Override public void init(FilterConfig config) throws ServletException { String name = config.getInitParameter( "name" ); String value = config.getInitParameter( "value" ); System.out.println( "name = " + name); System.out.println( "value = " + value); System.out.println( "init()....." ); } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { System.out.println( "FiveFilter doFilter()" ); } @Override public void destroy() { } } |