1.统一中文编码分析

tomcat默认esetISO-8859-1编码，在servlet中，可能通过request的setCharacterEncoding(charset)和response.setContentType("text/html;charset=UTF-8");处理post请求编码,但get请求的编码控制不了，所以，如果请求类型是get，则用装饰者模式把request整个调包

 

2.EncodingFilter.java

1 package cn.itcast.filter; 2  3 import java.io.IOException; 4  5 import javax.servlet.Filter; 6 import javax.servlet.FilterChain; 7 import javax.servlet.FilterConfig; 8 import javax.servlet.ServletException; 9 import javax.servlet.ServletRequest;10 import javax.servlet.ServletResponse;11 import javax.servlet.http.HttpServletRequest;12 13 14 public class EncodingFilter implements Filter {15     private String charset = "UTF-8";16     @Override17     public void destroy() {}18 19     @Override20     public void doFilter(ServletRequest request, ServletResponse response,21             FilterChain chain) throws IOException, ServletException {22         HttpServletRequest req = (HttpServletRequest) request;23         if(req.getMethod().equalsIgnoreCase("GET")) {24             if(!(req instanceof GetRequest)) {25                 req = new GetRequest(req, charset);//处理get请求编码26             }27         } else {28             req.setCharacterEncoding(charset);//处理post请求编码29         }30         chain.doFilter(req, response);31     }32 33     @Override34     public void init(FilterConfig fConfig) throws ServletException {35         String charset = fConfig.getInitParameter("charset");36         if(charset != null && !charset.isEmpty()) {37             this.charset = charset;38         }39     }40 }

3.GetRequest.java  装饰者模式

1 package cn.itcast.filter; 2  3 import java.io.UnsupportedEncodingException; 4 import java.util.Enumeration; 5 import java.util.Map; 6 import javax.servlet.http.HttpServletRequest; 7 import javax.servlet.http.HttpServletRequestWrapper; 8  9 /**10  * 对GET请求参数加以处理！11  * @author qdmmy612  *13  */14 public class GetRequest extends HttpServletRequestWrapper {15     private HttpServletRequest request;16     private String charset;17     18     public GetRequest(HttpServletRequest request, String charset) {19         super(request);20         this.request = request;21         this.charset = charset;22     }23 24     @Override25     public String getParameter(String name) {26         // 获取参数27         String value = request.getParameter(name);28         if(value == null) return null;//如果为null，直接返回null29         try {30             // 对参数进行编码处理后返回31             return new String(value.getBytes("ISO-8859-1"), charset);32         } catch (UnsupportedEncodingException e) {33             throw new RuntimeException(e);34         }35     }36     37     @SuppressWarnings({ "unchecked", "rawtypes" })38     @Override39     public Map getParameterMap() {40         Map
     
       map = request.getParameterMap();41         if(map == null) return map;42         // 遍历map，对每个值进行编码处理43         for(String key : map.keySet()) {44             String[] values = map.get(key);45             for(int i = 0; i < values.length; i++) {46                 try {47                     values[i] = new String(values[i].getBytes("ISO-8859-1"), charset);48                 } catch (UnsupportedEncodingException e) {49                     throw new RuntimeException(e);50                 }51             }52         }53         // 处理后返回54         return map;55     }56     57     @Override58     public String[] getParameterValues(String name) {59         String[] values = super.getParameterValues(name);60         for(int i = 0; i < values.length; i++) {61             try {62                 values[i] = new String(values[i].getBytes("ISO-8859-1"), charset);63             } catch (UnsupportedEncodingException e) {64                 throw new RuntimeException(e);65             }66         }67         return values;68     }69 }
     

3.BaseServlet.java

1 package cn.itcast.servlet; 2  3 import java.io.IOException; 4 import java.lang.reflect.Method; 5  6 import javax.servlet.ServletException; 7 import javax.servlet.http.HttpServlet; 8 import javax.servlet.http.HttpServletRequest; 9 import javax.servlet.http.HttpServletResponse;10 11 /**12  * BaseServlet用来作为其它Servlet的父类13  * 14  * @author qdmmy615  * 16  *         一个类多个请求处理方法，每个请求处理方法的原型与service相同！ 原型 = 返回值类型 + 方法名称 + 参数列表17  */18 @SuppressWarnings("serial")19 public class BaseServlet extends HttpServlet {20     @Override21     public void service(HttpServletRequest request, HttpServletResponse response)22             throws ServletException, IOException {23         response.setContentType("text/html;charset=UTF-8");//处理响应编码24         25         /**26          * 1. 获取method参数，它是用户想调用的方法 2. 把方法名称变成Method类的实例对象 3. 通过invoke()来调用这个方法27          */28         String methodName = request.getParameter("method");29         Method method = null;30         /**31          * 2. 通过方法名称获取Method对象32          */33         try {34             method = this.getClass().getMethod(methodName,35                     HttpServletRequest.class, HttpServletResponse.class);36         } catch (Exception e) {37             throw new RuntimeException("您要调用的方法：" + methodName + "它不存在！", e);38         }39         40         /**41          * 3. 通过method对象来调用它42          */43         try {44             String result = (String)method.invoke(this, request, response);45             if(result != null && !result.trim().isEmpty()) {
   //如果请求处理方法返回不为空46                 int index = result.indexOf(":");//获取第一个冒号的位置47                 if(index == -1) {
   //如果没有冒号，使用转发48                     request.getRequestDispatcher(result).forward(request, response);49                 } else {
   //如果存在冒号50                     String start = result.substring(0, index);//分割出前缀51                     String path = result.substring(index + 1);//分割出路径52                     if(start.equals("f")) {
   //前缀为f表示转发53                         request.getRequestDispatcher(path).forward(request, response);54                     } else if(start.equals("r")) {
   //前缀为r表示重定向55                         response.sendRedirect(request.getContextPath() + path);56                     }57                 }58             }59         } catch (Exception e) {60             throw new RuntimeException(e);61         }62     }63 }