降魔篇之springmvc專案開發

先說下專案裡面的過濾類

HiddenHttpMethodFilter

因為預設的tomcat不支援delete,put 等

所以需要在請求的方法包裝下支援下這些方法。

package com.oasystem.filter;
import java.io.IOException;
import java.util.Locale;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;

import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.web.filter.HiddenHttpMethodFilter;
public class MyHiddenHttpMethodFilter extends HiddenHttpMethodFilter{  
  
    private String methodParam = DEFAULT_METHOD_PARAM;  
      
    public void setMethodParam(String methodParam){  
        Assert.hasText(methodParam, "'methodParam' must not be empty");  
        this.methodParam = methodParam;  
    }  
      
    @Override  
    protected void doFilterInternal(HttpServletRequest request,  
            HttpServletResponse response, FilterChain filterChain)  
            throws ServletException, IOException {  
        String paramValue = request.getParameter(methodParam);  
        if (StringUtils.hasLength(paramValue)) {  
            String method = paramValue.toUpperCase(Locale.ENGLISH);  
                HttpServletRequest wrapper = new HttpMethodRequestWrapper(request, method);  
                filterChain.doFilter(wrapper, response);  
        }  else {  
            filterChain.doFilter(request, response);  
        }  
    }  
      
    private static class HttpMethodRequestWrapper extends HttpServletRequestWrapper {  
  
        private final String method;  
  
        public HttpMethodRequestWrapper(HttpServletRequest request, String method) {  
            super(request);  
            this.method = method;  
        }  
  
        @Override  
        public String getMethod() {  
            return this.method;  
        }  
    }  
      
}  

Assert

編寫程式碼時，我們總是會做出一些假設，斷言就是用於在程式碼中捕捉這些假設，可以將斷言看作是異常處理的一種高階形式。