[Java知识库]springboot 可重复读取请求参数处理

增加请求处理实现类，重写获取流方法

import org.apache.commons.lang3.exception.ExceptionUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
import java.nio.charset.Charset;

public class RepeatParRequestWrapper extends HttpServletRequestWrapper {
    private final static Logger LOGGER = LoggerFactory.getLogger(RepeatParRequestWrapper.class);

    /** 流数据存储，实现获取流接口从此处取数 */
    private final byte[] body;

    public RepeatParRequestWrapper(HttpServletRequest request, ServletResponse response) throws IOException {
        super(request);
        request.setCharacterEncoding("UTF-8");
        response.setCharacterEncoding("UTF-8");

        body = getBodyString(request).getBytes("UTF-8");
    }

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

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

            @Override
            public int available() throws IOException {
                return body.length;
            }

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

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

            @Override
            public void setReadListener(ReadListener readListener) {

            }
        };
    }

    private String getBodyString(ServletRequest request) {
        StringBuilder sb = new StringBuilder();
        BufferedReader reader = null;
        try (InputStream inputStream = request.getInputStream()) {
            reader = new BufferedReader(new InputStreamReader(inputStream, Charset.forName("UTF-8")));
            String line = "";
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (IOException e) {
            LOGGER.warn("getBodyString出现问题！");
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    LOGGER.error(ExceptionUtils.getMessage(e));
                }
            }
        }
        return sb.toString();
    }
}

过滤器，替换请求类

• 增加过滤器

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

import org.apache.commons.lang3.StringUtils;
import org.springframework.http.MediaType;

/**
 * 可重复获取参数 过滤器
 */
public class RepeatParFilter implements Filter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        ServletRequest requestWrapper = null;
        if (request instanceof HttpServletRequest
                && StringUtils.startsWithIgnoreCase(request.getContentType(), MediaType.APPLICATION_JSON_VALUE)) {
            requestWrapper = new RepeatParRequestWrapper((HttpServletRequest) request, response);
        }
        if (null == requestWrapper) {
            chain.doFilter(request, response);
        } else {
            chain.doFilter(requestWrapper, response);
        }
    }

    @Override
    public void destroy() {

    }
}

• 注册

import com.chan.hen.core.filter.RepeatParFilter;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * Filter配置
 */
@Configuration
public class FilterConfig
{
    @Bean
    public FilterRegistrationBean filterRegistration()
    {
        FilterRegistrationBean registration = new FilterRegistrationBean();
        registration.setFilter(new RepeatParFilter());
        registration.addUrlPatterns("/*");
        registration.setName("repeatParFilter");
        // 默认最后处理。注意优先级，如果有其他过滤器需要读参数，必须让该过滤器处于优先
        registration.setOrder(FilterRegistrationBean.LOWEST_PRECEDENCE);
        return registration;
    }

}

• 获取到ServletRequest对象判断转成RepeatParRequestWrapper对象，获取流操作数据即可。