项目中遇到一类请求，所有的请求都会将请求参数放在header头中，每个接口都需要单独处理，因此考虑做一层封装，统一进行转换。

基本思路是增加一个拦截器，由拦截器对请求头进行解析，并转换为参数

首先集成一个HttpServletRequestWrapper，使得当前请求持有所有的参数表

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Vector;public class ParameterRequestWrapper extends HttpServletRequestWrapper {private Map<String, String[]> params = new HashMap<>();/*** Constructs a request object wrapping the given request.** @param request* @throws IllegalArgumentException if the request is null*/public ParameterRequestWrapper(HttpServletRequest request) {super(request);//将参数表，赋予给当前的Map以便于持有request中的参数this.params.putAll(request.getParameterMap());}/*** 重载构造方法*/public ParameterRequestWrapper(HttpServletRequest request, Map<String, Object> extendParams) {this(request);//这里将扩展参数写入参数表addAllParameters(extendParams);}/*** 在获取所有的参数名,必须重写此方法，否则对象中参数值映射不上** @return*/@Overridepublic Enumeration<String> getParameterNames() {return new Vector(params.keySet()).elements();}/*** 重写getParameter方法** @param name 参数名* @return 返回参数值*/@Overridepublic String getParameter(String name) {String[] values = params.get(name);if (values == null || values.length == 0) {return null;}return values[0];}@Overridepublic String[] getParameterValues(String name) {String[] values = params.get(name);if (values == null || values.length == 0) {return null;}return values;}/*** 增加多个参数** @param otherParams 增加的多个参数*/public void addAllParameters(Map<String, Object> otherParams) {for (Map.Entry<String, Object> entry : otherParams.entrySet()) {addParameter(entry.getKey(), entry.getValue());}}/*** 增加参数** @param name  参数名* @param value 参数值*/public void addParameter(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)});}}}
}
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其次，集成一个Filter

import app.config.ParameterRequestWrapper;import org.apache.commons.lang.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.filter.OncePerRequestFilter;import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;@Component
public class ParamFilter extends OncePerRequestFilter {private final SiteUidRelatedUtils uidRelatedUtils;@Autowiredpublic ParamFilter(SiteUidRelatedUtils uidRelatedUtils) {this.uidRelatedUtils = uidRelatedUtils;}@Overrideprotected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {Map<String,Object> paramter = new HashMap<>(16);//这里获取请求头信息，并填入参数表String token = request.getHeader(TOKEN);paramter.put("token", token);//其它参数......ParameterRequestWrapper wrapper = new ParameterRequestWrapper(request, paramter);filterChain.doFilter(wrapper, response);return;}filterChain.doFilter(request, response);
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至此，将请求头的内容转换成参数，就可以通过实体类进行接收了。