Java学习之HttpClient的GET与POST请求

这篇随笔记录了HttpClient的GET和POST请求

使用maven构建依赖包，我使用的版本是4.5.3

<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.3</version>
</dependency>　

代码如下：

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

public class HttpRequest {
    private static final String USER_AGENT = "Mozilla/5.0";
    private static final String TOKEN = "Bearer adad2342dfbcdcb44232bf6a";
    private static final String CONTENT_TYPE = "application/x-www-form-urlencoded";
       //发送GET请求
    public static String sendGet(String url){
        String result = "";
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpGet httpGet = new HttpGet(url);
        httpGet.addHeader("User-Agent", USER_AGENT);
        httpGet.addHeader("Authorization", TOKEN);
        try{
            HttpResponse response = httpClient.execute(httpGet);
            HttpEntity entity = response.getEntity();
            result = EntityUtils.toString(entity);
        }catch (Exception e){
            e.printStackTrace();
        }
        return result;
    }
    //发送POST请求
    public static String sendPost(String url,Map<String,String> mapParam){
        String result = "";
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost(url);
        httpPost.setHeader("Content-Type",CONTENT_TYPE);
        httpPost.addHeader("User-Agent" ,USER_AGENT);
        httpPost.addHeader("Authorization", TOKEN);
        try{
            if (mapParam != null){
                List<NameValuePair> postData = new ArrayList<NameValuePair>();
                for (Map.Entry<String,String> entry : mapParam.entrySet()){
                    postData.add(new BasicNameValuePair(entry.getKey(),entry.getValue()));
                }
                httpPost.setEntity(new UrlEncodedFormEntity(postData, HTTP.UTF_8));
            }
            HttpResponse response = httpClient.execute(httpPost);
            HttpEntity entity = response.getEntity();
            result = EntityUtils.toString(entity);
        }catch (Exception e){
            e.printStackTrace();
        }
        return result;
    }
}