本文使用 HttpURLConnection 發送http請求(get、post)
URLConnection是個抽象類,它有兩個直接子類分別是HttpURLConnection和JarURLConnection。另外一個重要的類是URL,
通常URL可以通過傳給構造器一個String類型的參數來生成一個指向特定地址的URL實例。
每個 HttpURLConnection 實例都可用於生成單個請求,但是其他實例可以透明地共享連接到 HTTP 服務器的基礎網絡。
請求後在 HttpURLConnection 的 InputStream 或 OutputStream 上調用 close() 方法可以釋放與此實例關聯的網絡資源,
但對共享的持久連接沒有任何影響。如果在調用 disconnect() 時持久連接空閒,則可能關閉基礎套接字。
JAVA使用HttpURLConnection發送POST數據是依靠OutputStream流的形式發送;具體編碼過程中,參數是以字符串“name=XXX”這種形式發送
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
/**
* 功能說明:HttpClient - 通過發送Http請求獲取目標URL的數據
*/
public class TestURL {
/** 提交方式POST **/
public static final String SUBMIT_METHOD_POST = "POST";
/** 提交方式GET **/
public static final String SUBMIT_METHOD_GET = "GET";
/**
* 通過http請求獲取數據
* @param urlStr url地址,如:www.baidu.com
* @param param url的?後的參數,如:www.baidu.com?a=1&&b=2,則param爲"a=1&&b=2"
* @return 返回讀取到的數據(json字符串)
*/
public static String pub(String urlStr,String param,String method)
{
URL url = null;
HttpURLConnection connection = null;
StringBuffer buffer = new StringBuffer();
System.out.println("request:"+urlStr+"?"+param);
try {
/*建立連接*/
url = new URL(urlStr);
connection = (HttpURLConnection) url.openConnection();
/*設置連接屬性 */
connection.setDoOutput(true);// 使用 URL 連接進行輸出
connection.setDoInput(true);// 使用 URL 連接進行輸入
connection.setUseCaches(false);// 忽略緩存
connection.setRequestMethod(method);// 設置URL請求方法
/*設置請求屬性*/
connection.setRequestProperty("Content-Length",param.length()+"");
connection.setRequestProperty("Content-Type", "application/octet-stream");
connection.setRequestProperty("Connection", "Keep-Alive");// 維持長連接
connection.setRequestProperty("Charset", "UTF-8");// 設置編碼
/*建立輸出流,並寫入數據*/
OutputStream outputStream = connection.getOutputStream();
outputStream.write(param.getBytes("UTF-8"));
/*讀取數據*/
BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
reader.close();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (connection != null) {
connection.disconnect();
}
}
System.out.println("response:"+buffer.toString());
return buffer.toString();
}
/*測試*/
public static void main(String[] args) {
String urlStr="http://f.apiplus.cn/ssq.json";
String param="a=1";
pub(urlStr,param,SUBMIT_METHOD_POST);//地址就是:http://f.apiplus.cn/ssq.json?a=1
}}輸出結果:即 代碼中的兩個 輸出 語句:
request: http://f.apiplus.cn/ssq.json?a=1
response: {"rows":5,"code":"ssq","info":"免費接口隨機延遲3-6分鐘,實時接口請訪問www.opencai.net查詢、購買或續費","data":[{"expect":"2018075","opencode":"07,09,12,13,22,24+11","opentime":"2018-07-01 21:18:20","opentimestamp":1530451100},{"expect":"2018074","opencode":"09,11,14,20,27,30+09","opentime":"2018-06-28 21:18:20","opentimestamp":1530191900},{"expect":"2018073","opencode":"02,09,14,15,16,23+10","opentime":"2018-06-26 21:18:20","opentimestamp":1530019100},{"expect":"2018072","opencode":"11,16,19,22,25,30+08","opentime":"2018-06-24 21:18:20","opentimestamp":1529846300},{"expect":"2018071","opencode":"02,05,06,13,16,19+03","opentime":"2018-06-21 21:18:20","opentimestamp":1529587100}]}