HttpURLConnection重定向,获取及设置cookie

HttpURLConnection获取重定向地址和cookie的代码如下:

public  void first() throws Exception{
Map<String, String> paramsHashMap = new HashMap<String, String>();
paramsHashMap.put("IF_NO", "IF0002");
paramsHashMap.put("UID", "12345");
firstRequest(API_HTTP, paramsHashMap, "UTF-8");
}

private  void firstRequest(String path, Map<String, String> params, String encoding) throws Exception{
StringBuilder sb = new StringBuilder();
if(params!=null && !params.isEmpty()){
for(Map.Entry<String, String> entry : params.entrySet()){
sb.append(entry.getKey()).append('=');
sb.append(URLEncoder.encode(entry.getValue(), encoding));
sb.append('&');
}
sb.deleteCharAt(sb.length() - 1);
}
byte[] entity = sb.toString().getBytes();
HttpURLConnection conn = (HttpURLConnection) new URL(path).openConnection();
conn.setInstanceFollowRedirects(true);
conn.setConnectTimeout(5000);
conn.setRequestMethod("POST");
conn.setDoOutput(true);
conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
conn.setRequestProperty("Content-Length", String.valueOf(entity.length));
OutputStream outStream = conn.getOutputStream();
outStream.write(entity);
//获取重定向地址
redictURL= conn.getHeaderField( "Location" );

System.out.println("第一次请求重定向地址 location="+redictURL);
System.out.println("第一次请求 conn.getResponseCode()="+conn.getResponseCode());

//获取cookie
Map<String,List<String>> map=conn.getHeaderFields();
Set<String> set=map.keySet();
for (Iterator iterator = set.iterator(); iterator.hasNext();) {
String key = (String) iterator.next();
if (key.equals("Set-Cookie")) {
System.out.println("key=" + key+",开始获取cookie");
List<String> list = map.get(key);
StringBuilder builder = new StringBuilder();
for (String str : list) {
builder.append(str).toString();
}
firstCookie=builder.toString();
System.out.println("第一次得到的cookie="+firstCookie);
}
}

}

conn.setRequestMethod("POST");
conn.setRequestProperty("Cookie", firstCookie);