吐槽：微信api很无语，部分用xml，部分用json。

最近在找如何调用微信公众平台关于json相关的api比较方便，最后发现httpcliect和gson不错。如果你有更好的方式，请告诉我。

以下代码先了解如何使用gson和httpclient，有功夫再整到我的sophia里

import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStream;import java.io.Reader;import java.util.HashMap;import java.util.Map;import org.apache.http.Consts;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.StatusLine;import org.apache.http.client.ClientProtocolException;import org.apache.http.client.HttpResponseException;import org.apache.http.client.ResponseHandler;import org.apache.http.client.methods.CloseableHttpResponse;import org.apache.http.client.methods.HttpGet;import org.apache.http.client.methods.HttpPost;import org.apache.http.entity.ContentType;import org.apache.http.entity.StringEntity;import org.apache.http.impl.client.CloseableHttpClient;import org.apache.http.impl.client.HttpClients;import org.apache.http.util.EntityUtils;import com.google.gson.Gson;import com.google.gson.GsonBuilder;import com.google.gson.JsonObject;public class JsonTest {			/**	 * 获取access token	 * @return	 * @throws ClientProtocolException	 * @throws IOException	 */	public static String getToken() throws ClientProtocolException, IOException {				CloseableHttpClient httpclient = HttpClients.createDefault();		//		String appid = "eeeeeeee";		String secret = "eeeeeeeeeeeeeeee";		HttpGet httpget = new HttpGet("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" + appid + "&secret=" + secret) ;		ResponseHandler<JsonObject> rh = new ResponseHandler<JsonObject>() {		    @Override		    public JsonObject handleResponse(		            final HttpResponse response) throws IOException {		        StatusLine statusLine = response.getStatusLine();		        HttpEntity entity = response.getEntity();		        if (statusLine.getStatusCode() >= 300) {		            throw new HttpResponseException(		                    statusLine.getStatusCode(),		                    statusLine.getReasonPhrase());		        }		        if (entity == null) {		            throw new ClientProtocolException("Response contains no content");		        }		        Gson gson = new GsonBuilder().create();		        //ContentType contentType = ContentType.getOrDefault(entity);		        //Charset charset = contentType.getCharset();		        Reader reader = new InputStreamReader(entity.getContent());		        return gson.fromJson(reader, JsonObject.class);		    }		};		JsonObject myjson = httpclient.execute(httpget, rh);				System.out.println(myjson.get("access_token").getAsString());		return myjson.get("access_token").getAsString();	}				/**	 * 下载文件	 * @throws ClientProtocolException	 * @throws IOException	 */	public static void  downloadMediaFile(String token) throws ClientProtocolException, IOException {				String mediaId = "fdsddddddddddd";		String url = "http://file.api.weixin.qq.com/cgi-bin/media/get?access_token=ACCESS_TOKEN&media_id=MEDIA_ID";		url = url.replaceAll("ACCESS_TOKEN", token);		url = url.replaceAll("MEDIA_ID", mediaId);				CloseableHttpClient httpclient = HttpClients.createDefault();		HttpGet httpget = new HttpGet(url);		CloseableHttpResponse response = httpclient.execute(httpget);		try {		    HttpEntity entity = response.getEntity();		    if (entity != null) {		        long len = entity.getContentLength();		        if (len != -1) {		            byte[] content = EntityUtils.toByteArray(entity);		            System.out.println(response.getStatusLine());		            OutputStream os = new FileOutputStream("/Users/sssss/abc.jpg");					// 开始读取					 os.write(content);					// 完毕，关闭所有链接					os.close();							        } else {		            // Stream content out		        }		    }		} finally {		    response.close();		}			}		/**	 * post json格式数据包  ----- 客服消息	 * @param map	 * @throws ClientProtocolException	 * @throws IOException	 */	public static void postJsonData(Map map) throws ClientProtocolException, IOException {		String token = "lv3s0iunvVvEj9K3bz12xofvXfW1916ePLqZ7mN6mx7reY-IDzPTrwoErd4pSMD4eSps56QbmbaQ";		String url = "https://api.weixin.qq.com/cgi-bin/message/custom/send?access_token=ACCESS_TOKEN";		url = url.replaceAll("ACCESS_TOKEN", token);				CloseableHttpClient httpclient = HttpClients.createDefault();		Gson gson = new Gson();				StringEntity entity = new StringEntity(gson.toJson(map),		        ContentType.create("plain/text", Consts.UTF_8));		entity.setChunked(true);		HttpPost httppost = new HttpPost(url);		httppost.setEntity(entity);		CloseableHttpResponse response = httpclient.execute(httppost);				System.out.println(response.getStatusLine());			}	   public static void main(String[] args) throws ClientProtocolException, IOException {				String token = getToken();				downloadMediaFile(token);						//客服消息		Map map = new HashMap();		map.put("touser", "o3Y0et021tT_MVK2bdY1DhSWwFCc");		map.put("msgtype", "text");		Map m = new HashMap();		m.put("content", "hello world");				map.put("text", m);				postJsonData(map);	}}

不好意思，昨天晚上发表文章，csdn老失败。导致只有标题。

用gson和httpclient调用微信公众平台API