setconfig，setattribute和setheader无法解决

Question

我正在开发防盗应用程序，这是我的连接http类。

我有错误，我无法解决（（无法解析setConfig，setAttribute和setHeader））  我该怎么做才能解决它？

以下是代码：

package com.example.fatooma.location;

/**
 * Created by fatooma on 26/07/2017.
*/
import java.io.BufferedReader;
import java.io.InputStreamReader;


import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.HttpVersion;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import com.example.fatooma.location.Core;

public class HttpRmi {

static String url = "http://localhost/projectserver";

CloseableHttpClient httpClient = HttpClients.createDefault();
// Request configuration can be overridden at the request level.
// They will take precedence over the one set at the client level.
RequestConfig requestConfig = RequestConfig.custom().setSocketTimeout(5000).setConnectTimeout(5000).setConnectionRequestTimeout(5000).build();
HttpGet httpget = new HttpGet(url);
httpget.setConfig(requestConfig);
httpget.setHeader("User-Agent","Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101206 Firefox/3.6.13");
// Execution context can be customized locally.
HttpClientContext context = HttpClientContext.create();
// Contextual attributes set the local context level will take
// precedence over those set at the client level.
context.setAttribute("http.protocol.version",HttpVersion.HTTP_1_1);
try {
    // Execute the method
    HttpResponse response = httpClient.execute(httpget);
    int statusCode = response.getStatusLine().getStatusCode();
    if (statusCode != HttpStatus.SC_OK) {
        throw new IllegalStateException("Method failed: " + response.getStatusLine());
    }
    BufferedReader br = new BufferedReader(new InputStreamReader((response.getEntity().getContent())));
    StringBuffer buf = new StringBuffer();
    String output;
    while ((output = br.readLine()) != null) {
        buf.append(output);
    }
    content = buf.toString();
} catch(Exception e ) {
    throw e;
}
}  finally
    httpClient.close()
    }}