Springboot拦截器获取@RequestBody参数

文章目录

• • HttpContextUtils
  • HttpServletRequest 过滤器：流可重复读

HttpContextUtils

import javax.servlet.ServletRequest;
import javax.servlet.http.HttpServletRequest;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;

/**
 * HttpContextUtils 
 *
 * @author itdragons
 */
public class HttpContextUtils {
	
	/**
	 * 获取query参数
	 * @param request
	 * @return
	 */
	public static Map<String, String> getParameterMapAll(HttpServletRequest request) {
		Enumeration<String> parameters = request.getParameterNames();

		Map<String, String> params = new HashMap<>();
		while (parameters.hasMoreElements()) {
			String parameter = parameters.nextElement();
			String value = request.getParameter(parameter);
			params.put(parameter, value);
		}

		return params;
	}

	/**
	 * 获取请求Body
	 *
	 * @param request
	 * @return
	 */
	public static String getBodyString(ServletRequest request) {
		StringBuilder sb = new StringBuilder();
		InputStream inputStream = null;
		BufferedReader reader = null;
		try {
			inputStream = request.getInputStream();
			reader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8));
			String line = "";
			while ((line = reader.readLine()) != null) {
				sb.append(line);
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			if (inputStream != null) {
				try {
					inputStream.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if (reader != null) {
				try {
					reader.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		return sb.toString();
	}

}

()只能读取一次，所以当使用拦截器时，controller已经不能获取body中的参数。所以需要增加一个过滤器来解决，使流可以重复读取。代码如下

HttpServletRequest 过滤器：流可重复读

import com.xm.common.utils.HttpContextUtils;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;

/***
 * HttpServletRequest 过滤器
 * 解决: ()只能读取一次的问题
 * 目标: 流可重复读
 */
@Component
@WebFilter(filterName = "HttpServletRequestFilter", urlPatterns = "/")
@Order(10000)
public class HttpServletRequestFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        ServletRequest requestWrapper = null;
        if(servletRequest instanceof HttpServletRequest) {
            requestWrapper = new RequestWrapper((HttpServletRequest) servletRequest);
        }
        //获取请求中的流如何，将取出来的字符串，再次转换成流，然后把它放入到新request对象中
        // 在方法中传递新的request对象
        if(null == requestWrapper) {
            filterChain.doFilter(servletRequest, servletResponse);
        } else {
            filterChain.doFilter(requestWrapper, servletResponse);
        }
    }

    @Override
    public void destroy() {

    }

    /***
     * HttpServletRequest 包装器
     * 解决: ()只能读取一次的问题
     * 目标: 流可重复读
     */
    public class RequestWrapper extends HttpServletRequestWrapper {

        /**
         * 请求体
         */
        private String mBody;

        public RequestWrapper(HttpServletRequest request) {
            super(request);
            // 将body数据存储起来
            mBody = getBody(request);
        }

        /**
         * 获取请求体
         * @param request 请求
         * @return 请求体
         */
        private String getBody(HttpServletRequest request) {
            return HttpContextUtils.getBodyString(request);
        }

        /**
         * 获取请求体
         * @return 请求体
         */
        public String getBody() {
            return mBody;
        }

        @Override
        public BufferedReader getReader() throws IOException {
            return new BufferedReader(new InputStreamReader(getInputStream()));
        }

        @Override
        public ServletInputStream getInputStream() throws IOException {
            // 创建字节数组输入流
            final ByteArrayInputStream bais = new ByteArrayInputStream(mBody.getBytes(StandardCharsets.UTF_8));

            return new ServletInputStream() {
                @Override
                public boolean isFinished() {
                    return false;
                }

                @Override
                public boolean isReady() {
                    return false;
                }

                @Override
                public void setReadListener(ReadListener readListener) {

                }

                @Override
                public int read() throws IOException {
                    return bais.read();
                }
            };
        }
    }
}