如何在HttpFilter中修改HttpRequest主体参数

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class MyHttpFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        // 初始化操作
    }

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

        // 获取HttpRequest主体参数
        BufferedReader reader = new BufferedReader(new InputStreamReader(httpRequest.getInputStream()));
        StringBuilder bodyParams = new StringBuilder();
        String line;
        while ((line = reader.readLine()) != null) {
            bodyParams.append(line);
        }
        reader.close();

        // 修改HttpRequest主体参数
        String modifiedBodyParams = modifyBodyParams(bodyParams.toString());

        // 创建新的HttpRequest对象
        HttpServletRequest newRequest = new CustomHttpServletRequest(httpRequest, modifiedBodyParams);

        // 调用filterChain的doFilter方法
        chain.doFilter(newRequest, response);
    }

    @Override
    public void destroy() {
        // 销毁操作
    }

    private String modifyBodyParams(String bodyParams) {
        // 根据需求修改主体参数
        // 示例：将参数值替换为新值
        return bodyParams.replace("oldValue", "newValue");
    }
}

class CustomHttpServletRequest extends HttpServletRequestWrapper {
    private final String bodyParams;

    public CustomHttpServletRequest(HttpServletRequest request, String bodyParams) {
        super(request);
        this.bodyParams = bodyParams;
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(bodyParams.getBytes());
        return new ServletInputStream() {
            @Override
            public int read() throws IOException {
                return byteArrayInputStream.read();
            }
        };
    }
}