对于HttpGet类型，方法addHeader（String，String）是未定义的

Question

我有这个程序：

import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.HttpClientBuilder;

public class ApplicationRESTFul {

    public static void main(String[] args) {

        String url = "http://www.google.com/search?q=httpClient";

        HttpClient client = HttpClientBuilder.create().build();
        HttpGet request = new HttpGet(url);

        request.addHeader("Accept", "application/json");

    }

}

但是我从eclipse得到了这条消息

the method addHeader (String, String) is undefined for the type HttpGet

我正在使用这个库，正如我在文档中看到的那样，该方法应该存在（org.apache.httpcomponents.httpclient_4.5）

http://hc.apache.org/httpcomponents-client-ga/httpclient/apidocs/org/apache/http/client/methods/HttpGet.html

Answer 1

我通过将httpcore JAR添加到类路径来解决它。从maven添加依赖项也会添加httpcore JAR，而不仅仅是httpclient JAR，这也是它的原因。