在修改request参数值时报java.lang.StackOverflowError

Question

在升级一个很久很久以前的系统时遇到一个问题，使用的是tomcat8.5.57，这个版本的tomcat对请求参数的要求比较严格，不能含有中文，于是想了个办法，把请求中的中文编码，然后再filter中再把值转换成中文，这样就必须借助HttpServletRequestWrapper才能实现。这种方式在我本地测试时没有问题。但是放到生产环境之后，会报错，错误信息如下：这里只截取一部分，因为有很长，应该是死循环了，但是为啥死循环怎么才能避免，请教大佬指点，非常急！！！

Exception in thread "http-nio-19206-exec-7" java.lang.StackOverflowError

	   at org.apache.catalina.connector.RequestFacade.getSession(RequestFacade.java:887)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)
        at org.apache.catalina.core.ApplicationHttpRequest.getSession(ApplicationHttpRequest.java:596)
        at javax.servlet.http.HttpServletRequestWrapper.getSession(HttpServletRequestWrapper.java:231)

以下是我的代码：

1.ChangeRequestWrapper 包装request用的。
 

package filter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.util.Enumeration;
import java.util.Map;
import java.util.Vector;

public class ChangeRequestWrapper extends HttpServletRequestWrapper {
    private Map<String, String[]> parameterMap; // 所有参数的Map集合
 
    public ChangeRequestWrapper(HttpServletRequest request) {
        super(request);
        parameterMap = request.getParameterMap();
    }
 
    // 重写几个HttpServletRequestWrapper中的方法
 
    /**
     * 获取所有参数名
     *
     * @return 返回所有参数名
     */
    @Override
    public Enumeration<String> getParameterNames() {
        Vector<String> vector = new Vector<String>(parameterMap.keySet());
        return vector.elements();
    }
 
    /**
     * 获取指定参数名的值，如果有重复的参数名，则返回第一个的值 接收一般变量 ，如text类型
     *
     * @param name 指定参数名
     * @return 指定参数名的值
     */
    @Override
    public String getParameter(String name) {
        String[] values = parameterMap.get(name);
        if(values == null || values.length == 0) {
            return null;
        }
        return values[0];
    }
 
 
    /**
     * 获取指定参数名的所有值的数组，如：checkbox的所有数据
     * 接收数组变量 ，如checkobx类型
     */
    @Override
    public String[] getParameterValues(String name) {
        return parameterMap.get(name);
    }
 
    @Override
    public Map<String, String[]> getParameterMap() {
        return parameterMap;
    }
 
    public void setParameterMap(Map<String, String[]> parameterMap) {
        this.parameterMap = parameterMap;
    }
}

2.filter：
 

package filter;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.net.URLDecoder;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 * @description: 拦截器
 * @author: wjw
 * @create: 2020-10-27 15:20
 **/
public class CSPFilter  implements Filter{
    private FilterConfig config  = null;//初始化在init中
    private String strCSPValue  = null;//初始化在init中
    @Override
    public void init(FilterConfig filterConfig)
    {
        this.config  = filterConfig;
        this.strCSPValue = config.getInitParameter("CSPValue");
    }
    private void DayinCs(ChangeRequestWrapper request)
    {
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式
        String date = df.format(new Date());
        StringBuffer url= new StringBuffer();
        String queryurl=request.getQueryString();
        url.append(date + " url:"+request.getRequestURL());
        if(null!=queryurl){
            url.append("?"+queryurl);
        }
        System.out.println("url="+url.toString());
    }
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException
    {
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        // 使用我们自定义的响应包装器来包装原始的ServletResponse
        ResponseWrapper wrapper = new ResponseWrapper(response);
        ChangeRequestWrapper changeRequestWrapper = new ChangeRequestWrapper((HttpServletRequest) servletRequest);
        Map<String, String[]> parameterMap = new HashMap<>(changeRequestWrapper.getParameterMap());
        //处理中文请求头
        String[] nodeidentArr = parameterMap.get("nodeident");
        if (nodeidentArr != null && nodeidentArr.length > 0)
        {
            System.out.println("strings-====="+nodeidentArr);
            String[] strings = new String[1];
            strings[0] = URLDecoder.decode(nodeidentArr[0],"UTF-8");
            parameterMap.put("nodeident", strings);
            changeRequestWrapper.setParameterMap(parameterMap);
        }

        filterChain.doFilter(changeRequestWrapper, wrapper);
        // 处理截获的结果并进行处理，比如替换所有的“名称”为“铁木箱子”
        //后台已经把数据封装到缓冲区中，这里是取出来
        if(strCSPValue == null)
        {
            wrapper.addHeader("Content-Security-Policy", "default-src 'self'");//设置为默认限制
        }
        else
        {
            wrapper.addHeader("Content-Security-Policy", strCSPValue);//配置的CSP头
        }

        String strAgent = changeRequestWrapper.getParameter("agent");

        if(strAgent != null && strAgent.length() > 0)
        {
            DayinCs(changeRequestWrapper);
            System.out.println("strAgent="+strAgent);
            if(isNeedJavaScriptFilter(strAgent))
            {
                wrapper.setContentType("text/javascript;charset=GBK");
            }
            else if(isNeedCssFilter(strAgent))
            {
                wrapper.setContentType("text/css;charset=GBK");
            }
        }
        String result = wrapper.getResult();
        //后台数据编辑后，通过真正的response写到前台页面去
        response.getOutputStream().write(result.getBytes());
    }

    @Override
    public void destroy() {

    }

    /**
     * 是否是需要拦截的CSS请求
     * @param P_StrAgent
     * @return
     */
    private boolean isNeedCssFilter(String P_StrAgent)
    {
        if(
       true
        )
        {
            return true;
        }
        return false;
    }

    /**
     * 是否是需要拦截的javascript请求
     * @param P_StrAgent
     * @return
     */
    private boolean isNeedJavaScriptFilter(String P_StrAgent)
    {
        if(true)
        {
            return true;
        }
        return false;
    }

}

Answer 1

我第一次听说请求参数不能含有中文的