Android中与服务器通信

    服务器开发语言我选择的是php

    服务器搭建完成之后，在服务器www目录下写一个demo.php,php的代码如下：

   <?php
    if($_POST['username'] == "admin"){
        echo "admin";
    }else{
        echo "user";
    }
?>

  然后在安卓中向该服务器发送请求：

 

public class http extends AppCompatActivity {    HttpUtil httpUtil;    TextView textView;    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_http);        httpUtil = new HttpUtil();        Button button = (Button)findViewById(R.id.send);        textView = (TextView)findViewById(R.id.text3);        button.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View view) {              String str =   httpUtil.sendHttpRequest("http://115.159.217.226/demo.php");                textView.setText(str);            }        });    }}  先写一个http类，调用我自己写的sendHttpRequest()；方法  方法的代码如下：  
public class HttpUtil {    private OkHttpClient client;    private Request request;    private Response response;    public String str;    public String sendHttpRequest(final String address){        new Thread(new Runnable() {            String responseData;            public void run() {                try{                    client = new OkHttpClient();                    RequestBody requestBody = new FormBody.Builder()                            .add("username","admin")                            .build();                    request = new Request.Builder()                            .url(address)                            .post(requestBody)                            .build();                    response = client.newCall(request).execute();                    responseData = response.body().string();                    str = responseData;                }catch (Exception e){                    e.printStackTrace();                }            }        }).start();        return str;    }}
 最后得到数据为admin,向php服务器通信成功