java 微信开发获取access_token

获取微信接口

@RequestMapping("wx")@Controllerpublic class WxController extends BaseController {    String access_token = null;    private static final String appid = "xxx";    private static final String secret = "xxx";    private static final String grant_type = "client_credential";       /**     * 微信获取token     * @param request     * @return     */    @RequestMapping(value="/getToken",method=RequestMethod.GET)    @ResponseBody    public String getToken(HttpServletRequest request){//      Map<String, String> map = new HashMap<String, String>();        String status="";        try {            access_token = HttpRequest.sendGet("https://api.weixin.qq.com/cgi-bin/token",                    "grant_type=" + grant_type + "&appid=" + appid + "&secret=" + secret + "");        } catch (Exception e) {            e.printStackTrace();            status = "wrong";            return status;        }        return access_token;    }}

http请求实现

public class HttpRequest {    /**     * access_token获取     * @author xx     *     */    public static String sendGet (String url, String param){           String result = "";            BufferedReader in = null;            try {                String urlNameString = url + "?" + param;                URL realUrl = new URL(urlNameString);                // 打开和URL之间的连接                URLConnection connection = realUrl.openConnection();                // 设置通用的请求属性                connection.setRequestProperty("accept", "*/*");                connection.setRequestProperty("connection", "Keep-Alive");                connection.setRequestProperty("user-agent",                        "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");                // 建立实际的连接                connection.connect();                // 获取所有响应头字段                Map<String, List<String>> map = connection.getHeaderFields();                // 遍历所有的响应头字段                for (String key : map.keySet()) {                    System.out.println(key + "--->" + map.get(key));                }                // 定义 BufferedReader输入流来读取URL的响应                in = new BufferedReader(new InputStreamReader(                        connection.getInputStream()));                String line;                while ((line = in.readLine()) != null) {                    result += line;                }            } catch (Exception e) {                System.out.println("发送GET请求出现异常！" + e);                e.printStackTrace();            }            // 使用finally块来关闭输入流            finally {                try {                    if (in != null) {                        in.close();                    }                } catch (Exception e2) {                    e2.printStackTrace();                }            }            return result;    }}