Java: HttpURLConnection 模拟登录方法 (带cookie 的Post/Get)_20160908_七侠镇莫尛貝

// http://blog.csdn.net/woxueliuyun/article/details/43267365 package tool

class MyHttpUrlConn {
public static String cookieVal=""

public static void Get(String url_get,String str_param_url,String charset,String cookie) throws IOException  {
// 拼凑get请求的URL字串，使用URLEncoder.encode对特殊和不可见字符进行编码
//    String getURL = GET_URL + "?username="  + URLEncoder.encode("fat man", "utf-8");
String getURL = url_get + "?" + str_param_url
URL getUrl = new URL(getURL);
// 根据拼凑的URL，打开连接，URL.openConnection函数会根据URL的类型，
// 返回不同的URLConnection子类的对象，这里URL是一个http，因此实际返回的是HttpURLConnection
HttpURLConnection connection = (HttpURLConnection) getUrl
.openConnection();

if (cookie != null) {
//发送cookie信息上去，以表明自己的身份，否则会被认为没有权限
println("set cookieVal = [" + cookie + "]")
connection.setRequestProperty("Cookie", cookie);
}

// 进行连接，但是实际上get request要在下一句的connection.getInputStream()函数中才会真正发到
// 服务器
connection.connect();
// 取得输入流，并使用Reader读取
BufferedReader reader = new BufferedReader(new InputStreamReader(
connection.getInputStream(),charset));
System.out.println("Contents of get request:");
String lines;
while ((lines = reader.readLine()) != null)  {
System.out.println(lines);
}
println(" ")
reader.close();
// 断开连接
connection.disconnect();
}

public static String Post(String url_post,String str_param_body,String charset,boolean b_flag,String cookies) throws IOException  {
// Post请求的url，与get不同的是不需要带参数
URL postUrl = new URL(url_post);
// 打开连接
HttpURLConnection connection = (HttpURLConnection) postUrl
.openConnection();
// Output to the connection. Default is
// false, set to true because post
// method must write something to the
// connection
// 设置是否向connection输出，因为这个是post请求，参数要放在
// http正文内，因此需要设为true
if("" != cookies){
connection.setRequestProperty("Cookie", cookies);
}

connection.setDoOutput(true);
// Read from the connection. Default is true.
connection.setDoInput(true);
// Set the post method. Default is GET
connection.setRequestMethod("POST");
// Post cannot use caches
// Post 请求不能使用缓存
connection.setUseCaches(false);
// This method takes effects to
// every instances of this class.
// URLConnection.setFollowRedirects是static函数，作用于所有的URLConnection对象。
// connection.setFollowRedirects(true);

// This methods only
// takes effacts to this
// instance.
// URLConnection.setInstanceFollowRedirects是成员函数，仅作用于当前函数
connection.setInstanceFollowRedirects(b_flag);
// Set the content type to urlencoded,
// because we will write
// some URL-encoded content to the
// connection. Settings above must be set before connect!
// 配置本次连接的Content-type，配置为application/x-www-form-urlencoded的
// 意思是正文是urlencoded编码过的form参数，下面我们可以看到我们对正文内容使用URLEncoder.encode
// 进行编码
connection.setRequestProperty("Content-Type",
"application/x-www-form-urlencoded");
// 连接，从postUrl.openConnection()至此的配置必须要在connect之前完成，
// 要注意的是connection.getOutputStream会隐含的进行connect。
connection.connect();
DataOutputStream out = new DataOutputStream(connection
.getOutputStream());
// The URL-encoded contend
// 正文，正文内容其实跟get的URL中'?'后的参数字符串一致
//    String content = "userName=" + URLEncoder.encode("console", "utf-8");
//    content = content + "&password=" + URLEncoder.encode("12345678", "utf-8");

println("http param body = [" + str_param_body + "]")
// DataOutputStream.writeBytes将字符串中的16位的unicode字符以8位的字符形式写道流里面
out.writeBytes(str_param_body);

out.flush();

// 取得cookie，相当于记录了身份，供下次访问时使用
//    cookieVal = connection.getHeaderField("Set-Cookie").split(";")[0]
cookieVal = connection.getHeaderField("Set-Cookie")
println("get cookieVal = [" + cookieVal  + "]")

out.close(); // flush and close
BufferedReader reader = new BufferedReader(new InputStreamReader(
connection.getInputStream(),charset));
String line;
System.out.println("Contents of post request:");
while ((line = reader.readLine()) != null)  {
System.out.println(line);
}
println(" ")

reader.close();
connection.disconnect();

return cookieVal
}
}

String cookie_login = MyHttpUrlConn.Post(URL_LOGIN,"userName=admin&password=12345678","utf-8",false,"");

MyHttpUrlConn.Post(URL_POST_SAVE,"name=mxb&yearsold=6","utf-8",false,cookie_login);
MyHttpUrlConn.Get(URL_GET_VIEW,"name=mxb&yearsold=6","utf-8",cookie_login);