get调用HTTP接口

/**
	 * 调用对方接口方法
	 * @param url 对方或第三方提供的路径
	 * @param param 向对方或第三方发送的数据，大多数情况下给对方发送JSON数据让对方解析
	 */
	public static String sendGet(String url, String param) {
		String result = "";
		BufferedReader in = null;
		try {
			param = paramFormat(param);
			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(),"UTF-8"));
			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;
	}

	static String paramFormat(String paramStr){
		return paramStr.replaceAll(" ","+");
	}