HttpClient工具的應用

pom文件

<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpclient</artifactId>
		</dependency>

package com.mwk.http;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
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.util.EntityUtils;

public class HttpClient {

	/**
	 * 發送 post請求訪問本地應用並根據傳遞參數不同返回不同結果
	 * 
	 * @param url
	 *            調用的url
	 * @param map
	 *            參數與所傳值
	 * @return
	 */
	public static String postHttpCilent(String url, Map<String, Object> map) {
		// 創建默認的httpClient實例.
		CloseableHttpClient httpclient = HttpClients.createDefault();
		// 創建httppost
		HttpPost httppost = new HttpPost(url);
		// 創建參數隊列
		List<BasicNameValuePair> formparams = new ArrayList<>();
		Set<String> keys = map.keySet();
		for (String key : keys) {
			formparams.add(new BasicNameValuePair(key, (String) map.get(key)));
		}

		UrlEncodedFormEntity uefEntity;
		try {
			uefEntity = new UrlEncodedFormEntity(formparams, "UTF-8");
			httppost.setEntity(uefEntity);
			CloseableHttpResponse response = httpclient.execute(httppost);
			try {
				HttpEntity entity = response.getEntity();
				if (entity != null) {
					String result = EntityUtils.toString(entity, "UTF-8");
					return result;
				}
			} finally {
				response.close();
			}
		} catch (ClientProtocolException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e1) {
			e1.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			// 關閉連接,釋放資源
			try {
				httpclient.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return null;
	}

	

	public static void main(String[] args) {
		Map<String, Object> map = new HashMap<>();
		String url = "https://www.baidu.com/";
		System.out.println(postHttpCilent(url, map));
	}

}