Xamarin android 使用http协议上传字符串给服务器端

一.首先了解http协议

https://www.cnblogs.com/ranyonsue/p/5984001.html（推荐这篇文章）

二.使用http协议上传

public static string Upload(string urlPath, string content)

{

string mContent = “”;

try

{

string BOUNDARY = “———7d4a6d158c9”; // 定义数据分隔线

URL url = new URL(urlPath);

HttpURLConnection conn = (HttpURLConnection)url.OpenConnection();

// 发送POST请求必须设置如下两行

conn.DoOutput = true;

conn.DoInput = true;

conn.UseCaches = false;

conn.RequestMethod = “POST”;

conn.SetRequestProperty(“connection”, “Keep-Alive”);

conn.SetRequestProperty(“user-agent”, “Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)”);

conn.SetRequestProperty(“Charsert”, “UTF-8”);

conn.SetRequestProperty(“Content-Type”, “application/x-www-form-urlencoded; boundary=” + BOUNDARY);

Java.IO.OutputStream os = new Java.IO.DataOutputStream(conn.OutputStream);

Java.Lang.StringBuilder sb = new Java.Lang.StringBuilder();

/设置头参数/

sb.Append(“–”);

sb.Append(BOUNDARY);

sb.Append(“\r\n”);

/*填充内容*/
            sb.Append("Content-Disposition: form-data; name=\"userName\" \r\n\r\n");
            sb.Append(content);
            sb.Append("\r\n");

            /*设置尾参数*/
            sb.Append("\r\n--");
            sb.Append(BOUNDARY);
            sb.Append("--\r\n");


            byte[] data = Encoding.UTF8.GetBytes(sb.ToString());
            os.Write(data);
            os.Flush();
            os.Close();

            // 定义BufferedReader输入流来读取URL的响应
            Java.IO.BufferedReader reader = new Java.IO.BufferedReader(new Java.IO.InputStreamReader(conn.InputStream));
            string line = null;
            while ((line = reader.ReadLine()) != null)
            {
                mContent += line;
            }   
            System.Console.WriteLine(mContent + "//");
            return mContent;

        }
        catch (Java.Lang.Exception e)
        {

            //System.out.println("发送POST请求出现异常！" + e);
            //e.printStackTrace();
        }
        return mContent;
    }
           

服务器端接收值的代码是：

<%@page import=”com.jspsmart.upload.SmartUpload”%>

<%@ page language=”java” contentType=”text/html; charset=UTF-8”

pageEncoding=”UTF-8”%>

<%

SmartUpload su = new SmartUpload();

//初始化组件上下文

su.initialize(pageContext);

//设置编码

su.setCharset(“UTF-8”);

try {

su.upload();

} catch (Exception e) {

}
String clientContent=su.getRequest().getParameter("userName");
System.out.print("从android客户端传过来的用户名是："+clientContent);
           

%>

这样就实现点击客户端的Button按钮之后，在java服务器端的控制台中救打印出了 admin字符串

三.使用http协议也能实现向服务器端上传

private string UpLoadUserName(string serverUrl, string content)

{

string mContent = “”;

try

{

URL url = new URL(serverUrl);

HttpURLConnection conn = (HttpURLConnection)url.OpenConnection();

// 发送POST请求必须设置如下两行

conn.DoOutput = true;

conn.DoInput = true;

conn.UseCaches = false;

conn.RequestMethod = “POST”;

conn.SetRequestProperty(“connection”, “Keep-Alive”);

conn.SetRequestProperty(“user-agent”, “Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)”);

conn.SetRequestProperty(“Charsert”, “UTF-8”);

//conn.SetRequestProperty(“Content-Type”, “application/x-www-form-urlencoded; boundary=” + BOUNDARY);

Java.IO.OutputStream os = new Java.IO.DataOutputStream(conn.OutputStream);

Java.Lang.StringBuilder sb = new Java.Lang.StringBuilder();

sb.Append(“userName=” + content);

byte[] data = Encoding.UTF8.GetBytes(sb.ToString());

os.Write(data);

os.Flush();

os.Close();

// 定义BufferedReader输入流来读取URL的响应

Java.IO.BufferedReader reader = new Java.IO.BufferedReader(new Java.IO.InputStreamReader(conn.InputStream));

string line = null;

while ((line = reader.ReadLine()) != null)

{

mContent += line;

}

System.Console.WriteLine(mContent + “//”);

return mContent;

}

catch (Java.Lang.Exception e)

{

System.Console.WriteLine(“发送POST请求出现异常！！！” + e);

}

return mContent;

}
           

服务器端接收数据的代码：

<%@page import=”com.jspsmart.upload.SmartUpload”%>

<%@page import=”net.sf.json.JSONObject”%>

<%@ page language=”java” contentType=”text/html;charset=UTF-8”

pageEncoding=”UTF-8”%>

<%

String getName = request.getParameter(“userName”);

String clientContent = new String(getName.getBytes(“iso-8859-1”));//防止出现乱码

System.out.print(clientContent);

%>

区别就在于，不使用http协议上传，服务器端用的是系统自带的request类来接收客户端的请求！

如果使用http协议请求，服务器端用的是第三方的库 SmartUpLoad来接收客户端的传过来的数据！