HTTP 的get方法

public String sendGet(String url, String param) {
String result = "";
BufferedReader in = null;
try {
String urlName = url + "?" + param;
URL realUrl = new URL(urlName);
// 打开和URL之间的连接
URLConnection conn = realUrl.openConnection();
// 设置通用的请求属性
conn.setRequestProperty("accept", "*/*");
conn.setRequestProperty("connection", "Keep-Alive");
conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)");
// 建立实际的连接
conn.connect();
// 获取所有响应头字段
// Map<String, List<String>> map = conn.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(conn.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 (IOException ex) {
ex.printStackTrace();
}
}
return result;
}