java - com.android.volley.NoConnectionError : java.net.ConnectException:连接被拒绝

Question

我需要一些帮助。这是我的 Activity 登录，当单击登录按钮时，他给我一个错误:com.android.volley.NoConnectionError:java.net.ConnectException:Connection returned。我使用2个权限

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

这是我的登录代码，顶部有变量:

private EditText mPasswordView, mUserName;
    private ProgressBar loading;
    private Button btnLogin;
    private static String URL_LOGIN = "http://localhost/ligacao_bd/login.php";
    private View mProgressView;
    private View mLoginFormView;

这是我的按钮登录设置:

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

    loading = findViewById(R.id.loading);


    // Set up the login form.
    mUserName = (EditText) findViewById(R.id.textUserName);
    mPasswordView = (EditText) findViewById(R.id.textPassword);
    btnLogin = (Button) findViewById(R.id.btnLogin); // login button

    btnLogin.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View view) {
            String email = mUserName.getText().toString().trim();
            String Pwd = mPasswordView.getText().toString().trim();
            if(!email.isEmpty() || !Pwd.isEmpty()){
                Login(email, Pwd);
            }else{
               mUserName.setError("Insira nome de utilizador");
               mPasswordView.setError("Insira palavra-passe");
            }
        }
    });

还有我的带有 JSON 的登录函数，包括:

 private void Login(final String email, final String password) {

    loading.setVisibility(View.VISIBLE);
    btnLogin.setVisibility(View.GONE);
    StringRequest stringRequest = new StringRequest(Request.Method.POST, URL_LOGIN,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                   try {
                       JSONObject jsonObject = new JSONObject(response);
                       String success = jsonObject.getString("Sucesso");
                       JSONArray jsonArray = jsonObject.getJSONArray("login");

                       if(success.equals("1")) {

                            for (int i = 0; i < jsonArray.length(); i++){

                                JSONObject object = jsonArray.getJSONObject(i);

                                String nome = object.getString("nome").trim();
                                String email = object.getString("email").trim();

                                Toast.makeText(LoginActivity.this, "Login efetuado com sucesso\n Bem-Vindo " +nome, Toast.LENGTH_SHORT).show();

                                loading.setVisibility(View.GONE);
                            }
                       }


                   }catch (JSONException e){
                       e.printStackTrace();
                       loading.setVisibility(View.GONE);
                       btnLogin.setVisibility(View.VISIBLE);
                       Toast.makeText(LoginActivity.this, "Erro " + e.toString(), Toast.LENGTH_SHORT).show();

                   }
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    loading.setVisibility(View.GONE);
                    btnLogin.setVisibility(View.VISIBLE);
                    Toast.makeText(LoginActivity.this, "Erro " + error.toString(), Toast.LENGTH_SHORT).show();
                }
            })
    {
        @Override
        protected Map<String, String> getParams() throws AuthFailureError {
            Map<String, String> params = new HashMap<>();
            params.put("email", email);
            params.put("password", password);
            return params;
        }
    };

    RequestQueue requestQueue = Volley.newRequestQueue(this);
    requestQueue.add(stringRequest);

}

Answer 1

假设您在 Android 模拟器上运行此代码，并且您调用的任何后端服务也在本地主机上运行，​​请将您的登录地址更改为:

//8080 being the port that localhost is assigned to - change it if needs be
private static String URL_LOGIN = "http://10.0.2.2:8080/ligacao_bd/login.php";

http://10.0.2.2:xxxx是 IP，是主机环回接口(interface)的特殊别名(开发计算机上的 127.0.0.1)