package com.cx.web;

public class ParameterRequestWrapper extends HttpServletRequestWrapper {

    private Map<String, String[]> params = new HashMap<String, String[]>();

    @SuppressWarnings("unchecked")
    public ParameterRequestWrapper(HttpServletRequest request) {
        // 將request交給父類，以便於呼叫對應方法的時候，將其輸出，其實父親類的實現方式和第一種new的方式類似
        super(request);
        //將引數表，賦予給當前的Map以便於持有request中的引數
        this.params.putAll(request.getParameterMap());
        this.modifyParameterValues();
    }

    //過載一個構造方法
    public ParameterRequestWrapper(HttpServletRequest request, Map<String, Object> extendParams) {
        this(request);
        addAllParameters(extendParams);//這裡將擴充套件引數寫入引數表
    }

    public void modifyParameterValues() {//將parameter的值去除空格後重寫回去
        Set<String> set = params.keySet();
        Iterator<String> it = set.iterator();
        while (it.hasNext()) {
            String key = (String) it.next();
            String[] values = params.get(key);
            for (int i = 0; i < values.length; i++) {
                values[i] = values[i].trim();
            }
            params.put(key, values);
        }

    }

    @Override
    public Enumeration<String> getParameterNames() {
        return new Vector<String>(params.keySet()).elements();
    }
    @Override
    public String getParameter(String name) {//重寫getParameter，代表引數從當前類中的map獲取
        String[] values = params.get(name);
        if (values == null || values.length == 0) {
            return null;
        }
        return values[0];
    }

    public String[] getParameterValues(String name) {//同上
        return params.get(name);
    }


    public void addAllParameters(Map<String, Object> otherParams) {//增加多個引數
        for (Map.Entry<String, Object> entry : otherParams.entrySet()) {
            addParameter(entry.getKey(), entry.getValue());
        }
    }


    public void addParameter(String name, Object value) {//增加引數
        if (value != null) {
            if (value instanceof String[]) {
                params.put(name, (String[]) value);
            } else if (value instanceof String) {
                params.put(name, new String[]{(String) value});
            } else {
                params.put(name, new String[]{String.valueOf(value)});
            }
        }
    }
}
 

寫一個過濾器，在filter這個地方new了這個自己定義的request後，接下來request就是new出來的，這個filter一定要在springmvc之前處理，如下所示：

ParameterRequestWrapper requestWrapper = new ParameterRequestWrapper((HttpServletRequest)request);
requestWrapper.addParameter("fff" , "我靠");
filterChain.doFilter(requestWrapper, servletResponse);
 

package com.cx.web;
public class CommonFilter implements Filter {

    public CommonFilter() {
    }

    public void destroy() {
    }


    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest hr = (HttpServletRequest) request;

        long start = System.currentTimeMillis();

        String url = hr.getServletPath().trim();

        ParameterRequestWrapper requestWrapper = new ParameterRequestWrapper((HttpServletRequest) request);

        chain.doFilter(requestWrapper, response);

        long end = System.currentTimeMillis();

        System.out.println("============================連線：" + url + "，響應時間：" + (end - start));
    }

    public void init(FilterConfig fConfig) throws ServletException {
    }

}

<!--去引數的左右空格，也可以用springMVC攔截器實現-->
    <filter>
        <filter-name>commonFilter</filter-name>
        <filter-class>com.cx.web.CommonFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>commonFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>