[Spring] 封装request 自定义添加parameter

通过Filter实现

1 封装reqeust

要点在于 public void setParameter(String name, Object value) 方法。 将参数放入到自己的map中去。

package com.autoyong.filter;


import java.io.IOException;
import java.util.*;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;


public class   ParamServletRequestWrapper  extends HttpServletRequestWrapper {
    private Map<String , String[]> params = new HashMap<String, String[]>();

    public ParamServletRequestWrapper(HttpServletRequest request) throws IOException{
        super(request);
        this.params.putAll(request.getParameterMap());
    }

    public void addAllParameters(Map<String, Object> extraParams) {
        for (Map.Entry<String, Object> entry : extraParams.entrySet()) {
            setParameter(entry.getKey(), entry.getValue());
        }
    }

    public void setParameter(String name, Object value) {
        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)});
            }
        }
    }

    @Override
    public Enumeration<String> getParameterNames() {
        Vector<String> vector = new Vector<String>(params.keySet());
        return vector.elements();
    }

    /**
     * 重写getParameter，代表参数从当前类中的map获取
     * @param name
     * @return
     */
    @Override
    public String getParameter(String name) {
        String[]values = params.get(name);
        if(values == null || values.length == 0) {
            return null;
        }
        return values[0];
    }

    /**
     * 重写getParameterValues方法，从当前类的 map中取值
     * @param name
     * @return
     */
    @Override
    public String[] getParameterValues(String name) {
        return params.get(name);
    }
}

通过filter封装请求来的request

要点

1. @WebFilter 中的filterName 和类名要保持一致
2. 不要添加@compent 添加后过滤器会被加载两次。 然后过滤路径urlPatterns 会失效！

package com.autoyong.filter;


import com.autoyong.common.utils.AESUtil;
import com.autoyong.common.utils.StringUtils;
import org.springframework.core.annotation.Order;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


@Order(1)
@WebFilter(
        filterName = "BodyReaderRequestFilter", urlPatterns = "/xxxx/*")
public class BodyReaderRequestFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;
        ParamServletRequestWrapper requestWrapper = new ParamServletRequestWrapper(request);
        if (requestWrapper == null) {
            filterChain.doFilter(request, response);
        } else {
            String data = request.getParameter("data");
            if (!StringUtils.isEmpty(data)) {
                //校验数据项 是否数据不为空
                try {
                    if (!StringUtils.isEmpty(data)) {
                        data = AESUtil.DecryptByDefaultKey(data.trim());
                        System.out.println(data);
                        requestWrapper.setParameter("dataDto", data);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                } finally {
                    filterChain.doFilter(requestWrapper, response);
                }
            } else {
                filterChain.doFilter(request, response);
            }
        }
    }

    @Override
    public void destroy() {

    }
}