java 看了一个框架源码不知原因

Question

public class CustomRedirectStrategy extends LaxRedirectStrategy {
    private Logger logger = LoggerFactory.getLogger(getClass());

    @Override
    public HttpUriRequest getRedirect(HttpRequest request, HttpResponse response, HttpContext context) throws ProtocolException {
        URI uri = getLocationURI(request, response, context);
        String method = request.getRequestLine().getMethod();
        if ("post".equalsIgnoreCase(method)) {
            try {
                HttpRequestWrapper httpRequestWrapper = (HttpRequestWrapper) request;
                httpRequestWrapper.setURI(uri);
                httpRequestWrapper.removeHeaders("Content-Length");
                return httpRequestWrapper;
            } catch (Exception e) {
                logger.error("强转为HttpRequestWrapper出错");
            }
            return new HttpPost(uri);
        } else {
            return new HttpGet(uri);
        }
    }

源码地址：

https://github.com/code4craft/webmagic/blob/be892b80bf6682cd063d30ac25a79be0c079a901/webmagic-core/src/main/java/us/codecraft/webmagic/downloader/CustomRedirectStrategy.java

现在的http 协议请求都不需要头 httpRequestWrapper.removeHeaders("Content-Length");？？？？？

Answer 1

这个要看协议的具体设置了，有些是不需要content-length的，策略不同，我也只是知道大概，你可以找这2个参数，具体搜索一下。

Answer 2

它这是要重定向过去了，重定向拿这个请求头没有啥用吧，具体得看下RFC文档是怎么解释的