Android通过HttpURLConnection连接服务器并进行数据传输

demo包含GET及POST数据传输方法，将数据以键值对的形式存储到JSONobject里面，与服务器进行数据交互。

1.申请网络权限，在AndroidManifest.xml加入

<uses-permission android:name="android.permission.INTERNET"/>

2.编写服务器连接与交互代码

public class MainActivity extends AppCompatActivity {
    //界面控件
    Button btnTest;
    TextView tvTest;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        btnTest=(Button)findViewById(R.id.btn);
        tvTest=(TextView)findViewById(R.id.txt);

        btnTest.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                //在新线程中进行网络操作
                new Thread(){
                    @Override
                    public void run() {
                        try {
                            //选择请求方式
                            HttpURLConnectUtils http=new HttpURLConnectUtils();
                            String rlt=http.DoHttpPOST("输入网址");

                            //输出返回的结果
                            System.out.println(rlt);
                        } catch (MalformedURLException e1) {
                            e1.printStackTrace();
                        } catch (IOException e2) {
                            e2.printStackTrace();
                        }
                    }
                }.start();
            }
        });
    }

    //利用HttpURLConnection联系Http服务器
    public class HttpURLConnectUtils {

        private HttpURLConnectUtils() {

        }

        //post
        public String DoHttpPost(String mUrl) throws IOException {
            URL url = new URL(mUrl);
            //初始化创建HttpURLConnection实例
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();

            //设置当前连接的参数
            httpURLConnection.setConnectTimeout(5000); //推荐设置网络延时，如果不设置此项，获取响应状态码时可能引起阻塞
            httpURLConnection.setDoOutput(true);    //可写
            httpURLConnection.setDoInput(true);    //可读
            httpURLConnection.setUseCaches(false); //不用缓存

            //设置HttpURLConnection请求头里面的属性
            //设定传送的内容类型是可序列化的java对象
            //(如果不设此项,在传送序列化对象时,当WEB服务默认的不是这种类型时可能抛java.io.EOFException)
            //请求头里的属性需要自己根据服务器具体情况设定，下面两个可以不使用（因为这是我目前项目要求的头文件格式）
            httpURLConnection.setRequestProperty("Content-type", "application/json");
            httpURLConnection.setRequestProperty("accept", "application/json");
            //设置请求的方法
            httpURLConnection.setRequestMethod("POST");//Post请求

            //创建输出流，此时会隐含的进行connect
            OutputStream outputStream = httpURLConnection.getOutputStream();
            //创建字符流对象并用高效缓冲流包装它，便获得最高的效率,发送的是字符串推荐用字符流，其它数据就用字节流
            BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(outputStream));
            //输入所需信息
            String params = new String();
            JSONObject json = new JSONObject();
            try {
                json.put("Account", "System");
                json.put("Password", "123456");
                params = json.toString();
            }catch (Exception e){
            }
            //把json字符串写入缓冲区中
            bw.write(params);
            //提交参数
            bw.flush();
            outputStream.close();
            bw.close();

            //获取响应的状态码，判断是否请求成功
            int rltCode = httpURLConnection.getResponseCode();
            //获取响应状态码的描述,   正常返回"OK"
            String msg = httpURLConnection.getResponseMessage();
            if (rltCode != 200) //判断响应状态是否成功
            {
                System.out.println();
                return "Error Code--" + rltCode + ", Error Message--" + msg;
            }
            //接收返回值
            //创建文件流对象, InputStream-->InputStreamReader-->BufferedReader
            InputStreamReader inputStreamReader = new InputStreamReader(httpURLConnection.getInputStream());
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            //获取响应数据
            StringBuilder builder = new StringBuilder();
            //循环读取所有数据
            for (String s = bufferedReader.readLine(); s != null; s = bufferedReader.readLine()) {
                builder.append(s+"\n");
            }

            return builder.toString();
        }

        //get
        public String DoHttpGet(String mUrl) throws IOException {

            URL url = new URL(mUrl);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setConnectTimeout(5000);//推荐设置网络延时
            httpURLConnection.setReadTimeout(5000);//设置从主机读取数据超时（单位：毫秒）
            httpURLConnection.setRequestMethod("GET");

            //设置请求头属性
            httpURLConnection.setRequestProperty("accept", "application/json");

            httpURLConnection.connect(); //此处必须显式进行连接

            //以下同Post
            //获取响应的状态码，判断是否请求成功
            int rltCode = httpURLConnection.getResponseCode();
            String msg = httpURLConnection.getResponseMessage(); //获取响应状态码的描述, "OK"
            if (rltCode != 200) //判断响应状态是否成功
            {
                System.out.println();
                return "Error Code--" + rltCode + ", Error Message--" + msg;
            }

            //获取响应内容--读输入流
            InputStreamReader inputStreamReader = new InputStreamReader(httpURLConnection.getInputStream());
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            StringBuilder builder = new StringBuilder();
            for (String s = bufferedReader.readLine(); s != null; s = bufferedReader.readLine()) {
                builder.append(s);
            }

            return builder.toString();
        }
    }
}

3.补充一下，上述为用json传输数据，所以用字符串。但如果是图片之类的数据，需要用字节流，直接调用函数将图像之类的数据转化成Byte数据流，然后bw.write("比特流数据")即可。