android向服务器提交数据的几种方式

GET:

public static String loginByGet(String username,String password){
        try {
            //定义路径
            String path="http://192.168.1.102:8084/androidServer/loginServlet?username="
                    +URLEncoder.encode(URLEncoder.encode(username,"UTF-8"), "UTF-8")+"&password="+password;
            URL url=new URL(path);//包装路径
            HttpURLConnection conn=(HttpURLConnection) url.openConnection();//打开连接
            conn.setConnectTimeout(5000);//设置连接超时
            conn.setReadTimeout(5000);//设置读取超时
            conn.setRequestMethod("GET");//设置提交方式
            int code=conn.getResponseCode();//获取响应码
            if(code==200){
                //请求成功
                InputStream is=conn.getInputStream();//获取输入流
                ByteArrayOutputStream baos=new ByteArrayOutputStream();//定义字节数组输出流
                int len=0;
                byte[] buffer=new byte[1024];//设置缓存
                while((len=is.read(buffer))!=-1){
                    baos.write(buffer);//将缓存中的字节数据读入字节数组输出流
                }
                byte[] result=baos.toByteArray();//转换成字节数组
                String str=new String(result);//转换成字符串
                return str;
            }else{
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

POST:

public static String loginByPost(String username,String password){
        String path="http://192.168.1.102:8084/androidServer/loginServlet";//定义路径
        try {
            URL url=new URL(path);
            HttpURLConnection conn=(HttpURLConnection) url.openConnection();//打开连接
            //编码数据(post提交中文只编码一次，编码两次亦可，GET需要编码两次)
            String data="username="+URLEncoder.encode(URLEncoder.encode(username,"UTF-8"), "UTF-8")+"&password="+password;
            conn.setConnectTimeout(5000);
            conn.setReadTimeout(5000);
            conn.setRequestMethod("POST");
            //一下几项必须设置
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");//设置内容类型
            conn.setRequestProperty("Content-Length", data.length()+"");//设置内容长度
            conn.setDoOutput(true);//设置允许输出
            OutputStream os=conn.getOutputStream();//获取输出流
            os.write(data.getBytes());//输出数据
            int code=conn.getResponseCode();
            if(code==200){
                //请求成功
                InputStream is=conn.getInputStream();
                ByteArrayOutputStream baos=new ByteArrayOutputStream();
                int len=0;
                byte[] buffer=new byte[1024];
                while((len=is.read(buffer))!=-1){
                    baos.write(buffer);
                }
                byte[] result=baos.toByteArray();
                String str=new String(result);
                return str;
            }else{
                return null;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

HttpClient GET(模拟浏览器)：

public static String loginByClientGet(String username,String password){
        String str=null;
        try {
            //打开一个浏览器
            HttpClient client = new DefaultHttpClient();
            //输入地址
            String path = "http://192.168.1.102:8084/androidServer/loginServlet?username="
                    + URLEncoder.encode(URLEncoder.encode(username, "UTF-8"),"UTF-8") + "&password=" + password;
            HttpGet get = new HttpGet(path);//构建请求对象
            //敲回车
            HttpResponse response = client.execute(get);//获得相应结果
            if(response.getStatusLine().getStatusCode()==200){//判断状态码
                InputStream is=response.getEntity().getContent();//获取内容输入流
                ByteArrayOutputStream baos=new ByteArrayOutputStream();
                int len=0;
                byte[] buffer=new byte[1024];
                while((len=is.read(buffer))!=-1){
                    baos.write(buffer);
                }
                byte[] result=baos.toByteArray();
                str=new String(result);
                return str;
            }
        } catch (Exception e) {
            e.printStackTrace();
            return str;
        }
        return null;
    }

 HttpClient POST:

public static String loginByClientPOST(String username,String password){
        String str=null;
        try {
            //打开一个浏览器
            HttpClient client = new DefaultHttpClient();
            //输入地址
            String path = "http://192.168.1.102:8084/androidServer/loginServlet";
            HttpPost post = new HttpPost(path);
            //制定要提交的数据实体
            List<NameValuePair> parameters = new ArrayList<NameValuePair>();
            parameters.add(new BasicNameValuePair("username", username));//设置数据
            parameters.add(new BasicNameValuePair("password", password));
            post.setEntity(new UrlEncodedFormEntity(parameters, "UTF-8"));
            
            //敲回车（与get一致）
            HttpResponse response = client.execute(post);//获得相应结果
            if(response.getStatusLine().getStatusCode()==200){//判断状态码
                InputStream is=response.getEntity().getContent();//获取内容输入流
                ByteArrayOutputStream baos=new ByteArrayOutputStream();
                int len=0;
                byte[] buffer=new byte[1024];
                while((len=is.read(buffer))!=-1){
                    baos.write(buffer);
                }
                byte[] result=baos.toByteArray();
                str=new String(result);
                return str;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }

调用：

public void login(View v){
        final String username=et_username.getText().toString().trim();
        final String password=et_password.getText().toString().trim();
        
        new Thread(){
            public void run() {
                final String str=Service.loginByGet(username, password);
                if(str!=null){
                    runOnUiThread(new Runnable() {//joinUI线程更新界面
                        public void run() {
                            Toast.makeText(MainActivity.this, str, Toast.LENGTH_SHORT).show();
                        }
                    });
                }else{
                    runOnUiThread(new Runnable() {
                        public void run() {
                            Toast.makeText(MainActivity.this, "请求失败", Toast.LENGTH_SHORT).show();
                        }
                    });
                }
            };
        }.start();
    }

服务端servlet

public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=utf-8");//设置响应类型和编码
        PrintWriter out = response.getWriter();//获取输出流
        request.setCharacterEncoding("utf-8");//设置处理请求编码
        String username=URLDecoder.decode(request.getParameter("username"),"utf-8");//解码请求参数
        String password=request.getParameter("password");
        //System.out.println("username="+username+",password="+password);
        if("admin".equals(username)&&"123".equals(password)){
            out.print("登陆成功");
        }else{
            out.print("登录失败");
        }
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        doGet(request, response);
    }