【Android】Http请求

最新推荐文章于 2021-05-25 18:23:42 发布

最新推荐文章于 2021-05-25 18:23:42 发布 · 75 阅读

文章标签：

#移动开发 #json #java

本文介绍了一种使用Java实现HTTP请求的方法，包括POST和GET请求的具体实现，并提供了代码示例。文章详细展示了如何设置请求参数、处理响应及注意事项。

比较简单直接贴代码了。

package jftt.test; import java.io.IOException; import java.util.List; import org.apache.http.HttpResponse; import org.apache.http.HttpStatus; import org.apache.http.NameValuePair; import org.apache.http.client.ClientProtocolException; import org.apache.http.client.HttpClient; 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.DefaultHttpClient; import org.apache.http.params.BasicHttpParams; import org.apache.http.params.HttpConnectionParams; import org.apache.http.params.HttpParams; import android.util.Log; public class HttpRequest { /** *Post请求 */ public void doPost(String url , List<NameValuePair> nameValuePairs){ //新建HttpClient对象 HttpClient httpclient = new DefaultHttpClient(); //创建POST连接 HttpPost httppost = new HttpPost(url); try { // //使用PSOT方式，必须用NameValuePair数组传递参数 // List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); // nameValuePairs.add(new BasicNameValuePair("id", "12345")); // nameValuePairs.add(new BasicNameValuePair("stringdata","hps is Cool!")); httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); HttpResponse response = httpclient.execute(httppost); } catch (ClientProtocolException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } } /** *Get请求 */ public void doGet(String url){ HttpParams httpParams = new BasicHttpParams(); HttpConnectionParams.setConnectionTimeout(httpParams,30000); HttpConnectionParams.setSoTimeout(httpParams, 30000); HttpClient httpClient = new DefaultHttpClient(httpParams); // GET HttpGet httpGet = new HttpGet(url); try { HttpResponse response = httpClient.execute(httpGet); if (response.getStatusLine().getStatusCode() != HttpStatus.SC_OK){ Log.i("GET", "Bad Request!"); } } catch (IOException e) { e.printStackTrace(); } } }

需要主要的是:

1. 使用POST方式时，传递参数必须使用NameValuePair数组

2. 使用GET方式时，通过URL传递参数，注意写法

3.通过setEntity方法来发送HTTP请求

4.通过DefaultHttpClient 的 execute方法来获取HttpResponse

5. 通过getEntity()从Response中获取内容

String content = EntityUtils.toString(response.getEntity());

特别说明：

对于WCF的json服务，请求时如下：

/** *Post请求 * @throws IOException * @throws ClientProtocolException */ public static String doPost(String url , List<NameValuePair> nameValuePairs) throws ClientProtocolException, IOException{ String result = null; //新建HttpClient对象 HttpClient httpclient = new DefaultHttpClient(); //创建POST连接 HttpPost httppost = new HttpPost(url); httppost.setHeader("content-type", "application/json"); try { if(nameValuePairs != null) { StringEntity entity = new StringEntity("这里是JSON数据,如{"id":"12","name":"xiaoming"}", "utf-8"); entity.setContentType("application/json"); entity.setContentEncoding("utf-8"); httppost.setEntity(entity); } // if(nameValuePairs != null) { // httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs, HTTP.UTF_8)); // } HttpResponse response = httpclient.execute(httppost); if (response.getStatusLine().getStatusCode() != 404) { result = EntityUtils.toString(response.getEntity()); Logger.d(TAG, "Response: " + result); } } finally { } return result; }
其实就相当于传数据流的方式。