当前位置：极客笔记 > Android > Android 精选笔记 > Volley库 注册、登录和注销

Volley库 注册、登录和注销

Volley库 注册、登录和注销

在本教程中，我们将使用Volley库和JSON创建基本的用户注册和登录模块。Volley是一个提供网络连接功能的HTTP库。

使用Volley库的优势如下：

  • 更简单和更快的请求管理。
  • 提供高效的网络管理。

在服务器端数据处理方面，我们使用PHP和XAMPP服务器以及MySQL进行数据操作。

在创建Android应用程序模块之前，让我们先在PHP和MySQL中创建服务器端数据处理API代码，用于注册和登录。

1. 使用名称 registerlogin 创建一个数据库，并在其中创建名为 users 的表，该表包含以下字段。

Volley库 注册、登录和注销

2. 使用PHP和数据库内的以下连接建立代码，位于 C：\xampp\htdocs\androidphpmysql目录 。

在 androidphpmysql （您的项目位置）目录中，创建一个 connection.php 文件并编写以下代码。

connection.php

<?php  
servername = "localhost";username = "root";  
password = "";database = "registerlogin";  
conn = new mysqli(servername, username,password, database);  
if (conn->connect_error) {  
    die("Connection failed: " . $conn->connect_error);  
}  
?>

3. 在 androidphpmysql 目录下创建 registrationapi.php 文件，并写入以下代码。该文件处理来自安卓应用的请求，并将响应以JSON数组的形式返回给安卓应用。

registrationapi.php

<?php   
  require_once 'connection.php';  
  response = array();   if(isset(_GET['apicall'])){  
  switch(_GET['apicall']){   case 'signup':     if(isTheseParametersAvailable(array('username','email','password','gender'))){username = _POST['username'];email = _POST['email'];password = md5(_POST['password']);gender = _POST['gender'];stmt = conn->prepare("SELECT id FROM users WHERE username = ? OR email = ?");stmt->bind_param("ss", username,email);  
    stmt->execute();stmt->store_result();  

    if(stmt->num_rows>0){response['error'] = true;  
        response['message'] = 'User already registered';stmt->close();  
    }  
    else{  
        stmt =conn->prepare("INSERT INTO users (username, email, password, gender) VALUES (?, ?, ?, ?)");  
        stmt->bind_param("ssss",username, email,password, gender);  

        if(stmt->execute()){  
            stmt =conn->prepare("SELECT id, id, username, email, gender FROM users WHERE username = ?");   
            stmt->bind_param("s",username);  
            stmt->execute();stmt->bind_result(userid,id, username,email, gender);stmt->fetch();  

            user = array(             'id'=>id,   
            'username'=>username,              'email'=>email,  
            'gender'=>gender             );stmt->close();  

            response['error'] = false;response['message'] = 'User registered successfully';   
            response['user'] =user;   
        }  
    }  

}  
else{  
    response['error'] = true;response['message'] = 'required parameters are not available';   
}  
break;   
case 'login':  
  if(isTheseParametersAvailable(array('username', 'password'))){  
    username =_POST['username'];  
    password = md5(_POST['password']);   

    stmt =conn->prepare("SELECT id, username, email, gender FROM users WHERE username = ? AND password = ?");  
    stmt->bind_param("ss",username, password);stmt->execute();  
    stmt->store_result();     if(stmt->num_rows > 0){  
    stmt->bind_result(id, username,email, gender);stmt->fetch();  
    user = array(     'id'=>id,   
    'username'=>username,      'email'=>email,  
    'gender'=>gender     );response['error'] = false;   
    response['message'] = 'Login successfull';response['user'] = user;   }  else{response['error'] = false;   
    response['message'] = 'Invalid username or password';  }  
}  
break;   
default:response['error'] = true;   
 response['message'] = 'Invalid Operation Called';  
}  
}  
else{response['error'] = true;   
 response['message'] = 'Invalid API Call';  
}  
echo json_encode(response);  
function isTheseParametersAvailable(params){  
foreach(params as param){  if(!isset(_POST[$param])){  
     return false;   
  }  
}  
return true;   
}  
?>

检查您的PHP API是否正常工作，您可以使用Postman工具等REST客户端。

要检查API的注册代码，您可以使用参数来传递注册的URL。

Volley库 注册、登录和注销

同样，您可以通过传递有效的参数来检查登入操作的URL。

Volley库 注册、登录和注销

现在，在Android应用程序中，我们将为用户注册、用户登入和在主活动中显示用户详细信息（作为个人资料）创建三个Activity类。

在布局中创建一个 activity_main.xml 并添加以下代码。此活动用于显示用户的详细信息作为个人资料。

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>  
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    xmlns:app="http://schemas.android.com/apk/res-auto"  
    xmlns:tools="http://schemas.android.com/tools"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    tools:context="example.javatpoint.com.volleyregistrationloginsystem.MainActivity">  

    <LinearLayout  
        android:layout_width="match_parent"  
        android:layout_height="fill_parent"  
        android:layout_marginBottom="8dp"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="8dp"  
        android:orientation="vertical"  
        app:layout_constraintBottom_toBottomOf="parent"  
        app:layout_constraintEnd_toEndOf="parent"  
        app:layout_constraintHorizontal_bias="0.0"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toTopOf="parent"  
        app:layout_constraintVertical_bias="0.0">  

        <TextView  
            android:layout_width="fill_parent"  
            android:layout_height="wrap_content"  
            android:gravity="center"  
            android:text="Welcome to Profile"  
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Large" />  

        <TableLayout  
            android:layout_width="match_parent"  
            android:layout_height="wrap_content"  
            android:layout_marginTop="50dp">  


            <TableRow>  

                <TextView  
                    android:layout_width="wrap_content"  
                    android:layout_height="wrap_content"  
                    android:padding="10dp"  
                    android:text="Id"  
                    android:textAppearance="@style/Base.TextAppearance.AppCompat.Large" />  

                <TextView  
                    android:id="@+id/textViewId"  
                    android:layout_width="wrap_content"  
                    android:layout_height="wrap_content"  
                    android:padding="10dp"  
                    android:text="id"  
                    android:textAppearance="@style/Base.TextAppearance.AppCompat.Medium" />  

            </TableRow>  

            <TableRow>  

                <TextView  
                    android:layout_width="wrap_content"  
                    android:layout_height="wrap_content"  
                    android:padding="10dp"  
                    android:text="Username"  
                    android:textAppearance="@style/Base.TextAppearance.AppCompat.Large" />  

                <TextView  
                    android:id="@+id/textViewUsername"  
                    android:layout_width="wrap_content"  
                    android:layout_height="wrap_content"  
                    android:padding="10dp"  
                    android:text="username"  
                    android:textAppearance="@style/Base.TextAppearance.AppCompat.Medium" />  

            </TableRow>  

            <TableRow>  

                <TextView  
                    android:layout_width="wrap_content"  
                    android:layout_height="wrap_content"  
                    android:padding="10dp"  
                    android:text="Email"  
                    android:textAppearance="@style/Base.TextAppearance.AppCompat.Large" />  

                <TextView  
                    android:id="@+id/textViewEmail"  
                    android:layout_width="wrap_content"  
                    android:layout_height="wrap_content"  
                    android:padding="10dp"  
                    android:text="useremail"  
                    android:textAppearance="@style/Base.TextAppearance.AppCompat.Medium" />  

            </TableRow>  

            <TableRow>  

                <TextView  
                    android:layout_width="wrap_content"  
                    android:layout_height="wrap_content"  
                    android:padding="10dp"  
                    android:text="Gender"  
                    android:textAppearance="@style/Base.TextAppearance.AppCompat.Large" />  

                <TextView  
                    android:id="@+id/textViewGender"  
                    android:layout_width="wrap_content"  
                    android:layout_height="wrap_content"  
                    android:padding="10dp"  
                    android:text="gender"  
                    android:textAppearance="@style/Base.TextAppearance.AppCompat.Medium" />  

            </TableRow>  


        </TableLayout>  

        <Button  
            android:id="@+id/buttonLogout"  
            android:layout_width="210dp"  
            android:layout_height="50dp"  
            android:layout_marginTop="150dp"  
            android:layout_marginLeft="75dp"  
            android:text="Logout" />  
    </LinearLayout>  

</android.support.constraint.ConstraintLayout>

现在，在布局目录中创建一个名为activity_login.xml的文件，其中包含以下代码。此活动用于用户登录界面。

activity_login.xml

<?xml version="1.0" encoding="utf-8"?>  
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    xmlns:app="http://schemas.android.com/apk/res-auto"  
    xmlns:tools="http://schemas.android.com/tools"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    tools:context="example.javatpoint.com.volleyregistrationloginsystem.LoginActivity">  

    <TextView  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="16dp"  
        android:gravity="center"  
        android:text="Login"  
        android:textAppearance="@style/Base.TextAppearance.AppCompat.Large"  
        app:layout_constraintEnd_toEndOf="parent"  
        app:layout_constraintHorizontal_bias="1.0"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toTopOf="parent" />  

    <EditText  
        android:id="@+id/etUserName"  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
        android:layout_marginBottom="8dp"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="8dp"  
        android:ems="10"  
        android:inputType="textPersonName"  
        android:hint="user name"  
        app:layout_constraintBottom_toBottomOf="parent"  
        app:layout_constraintEnd_toEndOf="parent"  
        app:layout_constraintHorizontal_bias="0.0"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toTopOf="parent"  
        app:layout_constraintVertical_bias="0.144" />  

    <EditText  
        android:id="@+id/etUserPassword"  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="8dp"  
        android:hint="password"  
        android:ems="10"  
        android:inputType="textPassword"  
        app:layout_constraintEnd_toEndOf="parent"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toBottomOf="@+id/etUserName" />  

    <Button  
        android:id="@+id/btnLogin"  
        android:layout_width="210dp"  
        android:layout_height="50dp"  
        android:layout_marginBottom="8dp"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="8dp"  
        android:text="Login"  
        app:layout_constraintBottom_toBottomOf="parent"  
        app:layout_constraintEnd_toEndOf="parent"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toBottomOf="@+id/etUserName"  
        app:layout_constraintVertical_bias="0.754" />  

    <TextView  
        android:id="@+id/tvRegister"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_marginBottom="8dp"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="8dp"  
        android:gravity="center"  
        android:text="Create New Account\n Register Here"  
        app:layout_constraintBottom_toBottomOf="parent"  
        app:layout_constraintEnd_toEndOf="parent"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toBottomOf="@+id/btnLogin"  
        app:layout_constraintVertical_bias="0.405" />  

    <ProgressBar  
        android:id="@+id/progressBar"  
        android:visibility="gone"  
        style="?android:attr/progressBarStyle"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_marginBottom="8dp"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="8dp"  
        app:layout_constraintBottom_toBottomOf="parent"  
        app:layout_constraintEnd_toEndOf="parent"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toTopOf="parent"  
        app:layout_constraintVertical_bias="0.456" />  

</android.support.constraint.ConstraintLayout>

在layout目录中创建一个activity_register.xml文件，内容如下。该活动用于用户注册界面。

activity_register.xml

<?xml version="1.0" encoding="utf-8"?>  
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    xmlns:app="http://schemas.android.com/apk/res-auto"  
    xmlns:tools="http://schemas.android.com/tools"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    tools:context="example.javatpoint.com.volleyregistrationloginsystem.RegisterActivity">  


    <LinearLayout  
        android:layout_width="match_parent"  
        android:layout_height="519dp"  
        android:layout_centerVertical="true"  
        android:layout_marginBottom="8dp"  
        android:layout_marginEnd="8dp"  
        android:layout_marginStart="8dp"  
        android:layout_marginTop="8dp"  
        android:orientation="vertical"  
        android:padding="10dp"  
        app:layout_constraintBottom_toBottomOf="parent"  
        app:layout_constraintEnd_toEndOf="parent"  
        app:layout_constraintStart_toStartOf="parent"  
        app:layout_constraintTop_toTopOf="parent"  
        app:layout_constraintVertical_bias="0.0">  

        <TextView  
            android:layout_width="fill_parent"  
            android:layout_height="wrap_content"  
            android:text="Register"  
            android:gravity="center"  
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Large" />  

        <EditText  
            android:id="@+id/editTextUsername"  
            android:layout_width="match_parent"  
            android:layout_height="wrap_content"  
            android:layout_marginBottom="8dp"  
            android:layout_marginTop="20dp"  
            android:hint="Username"  
            android:inputType="text" />  

        <EditText  
            android:id="@+id/editTextEmail"  
            android:layout_width="match_parent"  
            android:layout_height="wrap_content"  
            android:layout_marginBottom="8dp"  
            android:layout_marginTop="8dp"  
            android:hint="Email"  
            android:inputType="textEmailAddress" />  

        <EditText  
            android:id="@+id/editTextPassword"  
            android:layout_width="match_parent"  
            android:layout_height="wrap_content"  
            android:layout_marginBottom="8dp"  
            android:layout_marginTop="8dp"  
            android:fontFamily="sans-serif"  
            android:hint="Password"  
            android:inputType="textPassword" />  

        <RadioGroup  
            android:id="@+id/radioGender"  
            android:layout_width="match_parent"  
            android:layout_height="wrap_content"  
            android:layout_marginBottom="8dp"  
            android:layout_marginTop="8dp"  
            android:orientation="horizontal">  

            <RadioButton  
                android:id="@+id/radioButtonMale"  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:checked="true"  
                android:text="Male" />  


            <RadioButton  
                android:id="@+id/radioButtonFemale"  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:text="Female" />  

        </RadioGroup>  

        <Button  
            android:id="@+id/buttonRegister"  
            android:layout_width="match_parent"  
            android:layout_height="wrap_content"  
            android:layout_marginBottom="8dp"  
            android:layout_marginTop="90dp"  
            android:text="Register" />  

        <TextView  
            android:id="@+id/textViewLogin"  
            android:layout_width="match_parent"  
            android:layout_height="wrap_content"  
            android:layout_marginBottom="8dp"  
            android:layout_marginTop="8dp"  
            android:text="Already Registered?\nLogin Here"  
            android:textAlignment="center"  
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Medium" />  
    </LinearLayout>  

    <ProgressBar  
        android:visibility="gone"  
        android:id="@+id/progressBar"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_centerHorizontal="true"  
        android:layout_centerVertical="true" />  

</android.support.constraint.ConstraintLayout>

在 build.gradle 文件中添加 volley 库依赖。

build.gradle

implementation 'com.android.volley:volley:1.0.0'

创建一个名为 User.java 的数据模型类，包含以下代码。

User.java

package example.javatpoint.com.volleyregistrationloginsystem;


public class User {
    private int id;
    private String name, email, gender;

    public User(int id, String name, String email, String gender) {
        this.id = id;
        this.email = email;
        this.gender = gender;
        this.name = name;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }


    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }
}

我们需要定义一个调用服务器端API的URL。

创建一个URLs.java类并定义URL。

URLs.java

package example.javatpoint.com.volleyregistrationloginsystem;  

public class URLs {
    private static final String ROOT_URL = "http://192.168.1.35/androidphpmysql/registrationapi.php?apicall=";
    public static final String URL_REGISTER = ROOT_URL + "signup";
    public static final String URL_LOGIN= ROOT_URL + "login";
}

VolleySingleton.java

package example.javatpoint.com.volleyregistrationloginsystem;  

import android.content.Context;  
import com.android.volley.Request;  
import com.android.volley.RequestQueue;  
import com.android.volley.toolbox.Volley;  

public class VolleySingleton {  
    private static VolleySingleton mInstance;  
    private RequestQueue mRequestQueue;  
    private static Context mCtx;  

    private VolleySingleton(Context context) {  
        mCtx = context;  
        mRequestQueue = getRequestQueue();  
    }  

    public static synchronized VolleySingleton getInstance(Context context) {  
        if (mInstance == null) {  
            mInstance = new VolleySingleton(context);  
        }  
        return mInstance;  
    }  

    public RequestQueue getRequestQueue() {  
        if (mRequestQueue == null) {  
            // getApplicationContext() is key, it keeps you from leaking the  
            // Activity or BroadcastReceiver if someone passes one in.  
            mRequestQueue = Volley.newRequestQueue(mCtx.getApplicationContext());  
        }  
        return mRequestQueue;  
    }  

    public <T> void addToRequestQueue(Request<T> req) {  
        getRequestQueue().add(req);  
    }  
}

创建一个名为SharedPreferences.java的类。在这个类中，我们使用SharedPreferences类来存储用户详细信息。SharedPreferences类包含以下四个方法：

  • userLogin(): 此方法用于在登录后将用户信息存储在SharedPreferences中。
  • isLoggedIn(): 此方法检查用户是否已登录。
  • getUser(): 此方法在登录状态下获取用户信息。
  • logout(): 此方法清除SharedPreferences数据并注销用户。

SharedPrefManager.java

package example.javatpoint.com.volleyregistrationloginsystem;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;

public class SharedPrefManager {

    private static final String SHARED_PREF_NAME = "volleyregisterlogin";
    private static final String KEY_USERNAME = "keyusername";
    private static final String KEY_EMAIL = "keyemail";
    private static final String KEY_GENDER = "keygender";
    private static final String KEY_ID = "keyid";
    private static SharedPrefManager mInstance;
    private static Context ctx;

    private SharedPrefManager(Context context) {
        ctx = context;
    }
    public static synchronized SharedPrefManager getInstance(Context context) {
        if (mInstance == null) {
            mInstance = new SharedPrefManager(context);
        }
        return mInstance;
    }

    //this method will store the user data in shared preferences
    public void userLogin(User user) {
        SharedPreferences sharedPreferences = ctx.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putInt(KEY_ID, user.getId());
        editor.putString(KEY_USERNAME, user.getName());
        editor.putString(KEY_EMAIL, user.getEmail());
        editor.putString(KEY_GENDER, user.getGender());
        editor.apply();
    }

    //this method will checker whether user is already logged in or not
    public boolean isLoggedIn() {
        SharedPreferences sharedPreferences = ctx.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
        return sharedPreferences.getString(KEY_USERNAME, null) != null;
    }

    //this method will give the logged in user
    public User getUser() {
        SharedPreferences sharedPreferences = ctx.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
        return new User(
                sharedPreferences.getInt(KEY_ID, -1),
                sharedPreferences.getString(KEY_USERNAME, null),
                sharedPreferences.getString(KEY_EMAIL, null),
                sharedPreferences.getString(KEY_GENDER, null)
        );
    }

    //this method will logout the user
    public void logout() {
        SharedPreferences sharedPreferences = ctx.getSharedPreferences(SHARED_PREF_NAME, Context.MODE_PRIVATE);
        SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.clear();
        editor.apply();
        ctx.startActivity(new Intent(ctx, LoginActivity.class));
    }
}

现在，在 MainActivity.java 类中，如果用户登录，则显示用户信息，否则跳转到 LoginActivity.java 类。当点击按钮时，使用 onClick() 方法退出登录。

MainActivity.java

package example.javatpoint.com.volleyregistrationloginsystem;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    TextView id,userName,userEmail,gender;
    Button btnLogout;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        if(SharedPrefManager.getInstance(this).isLoggedIn()){
            id = findViewById(R.id.textViewId);
            userName = findViewById(R.id.textViewUsername);
            userEmail = findViewById(R.id.textViewEmail);
            gender = findViewById(R.id.textViewGender);
            btnLogout = findViewById(R.id.buttonLogout);
            User user = SharedPrefManager.getInstance(this).getUser();

            id.setText(String.valueOf(user.getId()));
            userEmail.setText(user.getEmail());
            gender.setText(user.getGender());
            userName.setText(user.getName());

            btnLogout.setOnClickListener(this);
        }
        else{
            Intent  intent = new Intent(MainActivity.this,LoginActivity.class);
            startActivity(intent);
            finish();
        }
    }
    public void onClick(View view){
        if(view.equals(btnLogout)){
            SharedPrefManager.getInstance(getApplicationContext()).logout();
        }
    }
}

在 LoginActivity.java 类中，我们检查用户是否已经登录，如果是，则重定向到 MainActivity.java 类，否则允许用户登录。

StringRequest 类是 Volley 库中用于网络模块的类。StringRequest类的对象接受请求方法类型、URL和响应的参数。

LoginActivity.java

package example.javatpoint.com.volleyregistrationloginsystem;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;
import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.HashMap;
import java.util.Map;

public class LoginActivity extends AppCompatActivity {
    EditText etName, etPassword;
    ProgressBar progressBar;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);

        if (SharedPrefManager.getInstance(this).isLoggedIn()) {
            finish();
            startActivity(new Intent(this, MainActivity.class));
        }

        progressBar = findViewById(R.id.progressBar);
        etName = findViewById(R.id.etUserName);
        etPassword = findViewById(R.id.etUserPassword);



        //调用userLogin()方法登录用户
        findViewById(R.id.btnLogin).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                userLogin();
            }
        });

        //如果用户点击未注册的文本，则调用RegisterActivity
        findViewById(R.id.tvRegister).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                finish();
                startActivity(new Intent(getApplicationContext(), RegisterActivity.class));
            }
        });
    }

    private void userLogin() {
        //首先获取值
        final String username = etName.getText().toString();
        final String password = etPassword.getText().toString();
        //验证输入
        if (TextUtils.isEmpty(username)) {
            etName.setError("请输入用户名");
            etName.requestFocus();
            return;
        }

        if (TextUtils.isEmpty(password)) {
            etPassword.setError("请输入密码");
            etPassword.requestFocus();
            return;
        }

        //如果一切都没问题
        StringRequest stringRequest = new StringRequest(Request.Method.POST, URLs.URL_LOGIN,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        progressBar.setVisibility(View.GONE);

                        try {
                            //将响应转换为JSONObject对象
                            JSONObject obj = new JSONObject(response);

                            //如果响应中没有错误
                            if (!obj.getBoolean("error")) {
                                Toast.makeText(getApplicationContext(), obj.getString("message"), Toast.LENGTH_SHORT).show();

                                //从响应中获取用户信息
                                JSONObject userJson = obj.getJSONObject("user");

                                //创建一个新的用户对象
                                User user = new User(
                                        userJson.getInt("id"),
                                        userJson.getString("username"),
                                        userJson.getString("email"),
                                        userJson.getString("gender")
                                );

                                //将用户存储在共享首选项中
                                SharedPrefManager.getInstance(getApplicationContext()).userLogin(user);
                                //启动个人资料页面
                                finish();
                                startActivity(new Intent(getApplicationContext(), MainActivity.class));
                            } else {
                                Toast.makeText(getApplicationContext(), obj.getString("message"), Toast.LENGTH_SHORT).show();
                            }
                        } catch (JSONException e) {
                            e.printStackTrace();
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_SHORT).show();

                    }
                })
        {
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String, String> params = new HashMap<>();
                params.put("username", username);
                params.put("password", password);
                return params;
            }
        };

        VolleySingleton.getInstance(this).addToRequestQueue(stringRequest);
    }
}

RegisterActivity.java类用于用户注册。这个类最初检查用户登录，如果登录成功，则重定向至MainActivity.java类；否则，允许用户进行注册。

与LoginActivity.java类类似，我们使用Volley库的StringRequest类进行网络连接，并传递请求方法、URL和响应参数。Response.Listener< String >()方法处理服务器生成的响应。

RegisterActivity.java类 

package example.javatpoint.com.volleyregistrationloginsystem;  

import android.content.Intent;  
import android.support.v7.app.AppCompatActivity;  
import android.os.Bundle;  
import android.text.TextUtils;  
import android.view.View;  
import android.widget.EditText;  
import android.widget.ProgressBar;  
import android.widget.RadioButton;  
import android.widget.RadioGroup;  
import android.widget.Toast;  
import com.android.volley.AuthFailureError;  
import com.android.volley.Request;  
import com.android.volley.Response;  
import com.android.volley.VolleyError;  
import com.android.volley.toolbox.StringRequest;  
import org.json.JSONException;  
import org.json.JSONObject;  
import java.util.HashMap;  
import java.util.Map;  

public class RegisterActivity extends AppCompatActivity {  
    EditText editTextUsername, editTextEmail, editTextPassword;  
    RadioGroup radioGroupGender;  
    ProgressBar progressBar;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_register);  
        progressBar = findViewById(R.id.progressBar);  

        //if the user is already logged in we will directly start the MainActivity (profile) activity  
        if (SharedPrefManager.getInstance(this).isLoggedIn()) {  
            finish();  
            startActivity(new Intent(this, MainActivity.class));  
            return;  
        }  

        editTextUsername = findViewById(R.id.editTextUsername);  
        editTextEmail = findViewById(R.id.editTextEmail);  
        editTextPassword = findViewById(R.id.editTextPassword);  
        radioGroupGender = findViewById(R.id.radioGender);  


        findViewById(R.id.buttonRegister).setOnClickListener(new View.OnClickListener() {  
            @Override  
            public void onClick(View view) {  
                //if user pressed on button register  
                //here we will register the user to server  
                registerUser();  
            }  
        });  

        findViewById(R.id.textViewLogin).setOnClickListener(new View.OnClickListener() {  
            @Override  
            public void onClick(View view) {  
                //if user pressed on textview that already register open LoginActivity  
                finish();  
                startActivity(new Intent(RegisterActivity.this, LoginActivity.class));  
            }  
        });  

    }  

    private void registerUser() {  
        final String username = editTextUsername.getText().toString().trim();  
        final String email = editTextEmail.getText().toString().trim();  
        final String password = editTextPassword.getText().toString().trim();  

        final String gender = ((RadioButton) findViewById(radioGroupGender.getCheckedRadioButtonId())).getText().toString();  

        //first we will do the validations  
        if (TextUtils.isEmpty(username)) {  
            editTextUsername.setError("Please enter username");  
            editTextUsername.requestFocus();  
            return;  
        }  

        if (TextUtils.isEmpty(email)) {  
            editTextEmail.setError("Please enter your email");  
            editTextEmail.requestFocus();  
            return;  
        }  

        if (!android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {  
            editTextEmail.setError("Enter a valid email");  
            editTextEmail.requestFocus();  
            return;  
        }  

        if (TextUtils.isEmpty(password)) {  
            editTextPassword.setError("Enter a password");  
            editTextPassword.requestFocus();  
            return;  
        }  

        StringRequest stringRequest = new StringRequest(Request.Method.POST, URLs.URL_REGISTER,  
                new Response.Listener<String>() {  
                    @Override  
                    public void onResponse(String response) {  
                        progressBar.setVisibility(View.GONE);  

                        try {  
                            //converting response to json object  
                            JSONObject obj = new JSONObject(response);  
                            //if no error in response  
                            if (!obj.getBoolean("error")) {  
                                Toast.makeText(getApplicationContext(), obj.getString("message"), Toast.LENGTH_SHORT).show();  

                                //getting the user from the response  
                                JSONObject userJson = obj.getJSONObject("user");  

                                //creating a new user object  
                                User user = new User(  
                                        userJson.getInt("id"),  
                                        userJson.getString("username"),  
                                        userJson.getString("email"),  
                                        userJson.getString("gender")  
                                );  

                                //storing the user in shared preferences  
                                SharedPrefManager.getInstance(getApplicationContext()).userLogin(user);  

                                //starting the profile activity  
                                finish();  
                                startActivity(new Intent(getApplicationContext(), MainActivity.class));  
                            } else {  
                                Toast.makeText(getApplicationContext(), obj.getString("message"), Toast.LENGTH_SHORT).show();  
                            }  
                        } catch (JSONException e) {  
                            e.printStackTrace();  
                        }  
                    }  
                },  
                new Response.ErrorListener() {  
                    @Override  
                    public void onErrorResponse(VolleyError error) {  
                        Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_SHORT).show();  
                    }  
                }) {  
            @Override  
            protected Map<String, String> getParams() throws AuthFailureError {  
                Map<String, String> params = new HashMap<>();  
                params.put("username", username);  
                params.put("email", email);  
                params.put("password", password);  
                params.put("gender", gender);  
                return params;  
            }  
        };  

        VolleySingleton.getInstance(this).addToRequestQueue(stringRequest);  
    }  
}

将以下权限添加到 AndroidManifest.xml 文件中

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

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="example.javatpoint.com.volleyregistrationloginsystem">
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
    <uses-permission android:name="android.permission.INTERNET"/>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".LoginActivity" />
        <activity android:name=".RegisterActivity"></activity>
    </application>

</manifest>

输出：

Volley库 注册、登录和注销

Camera课程

Camera API2 教程

API2 教程
Camera 性能教程

Perf 教程
Camera Native Framework 教程

Native FW 教程
Camera QCOM ISP 教程

ISP 教程
Camera QCOM Sensor 教程

Sensor 教程

Python教程

Python 教程

Python 教程
NumPy 教程

NumPy 教程
Django 教程

Django 教程

Java教程

Java 教程

Java 教程

Web教程

JavaScript 教程

JavaScript 教程
jQuery 教程

jQuery 教程
CSS 教程

CSS 教程
PHP 教程

PHP 教程
Laravel 教程

Laravel 教程
TypeScript 教程

TypeScript 教程
WordPress 教程

WordPress 教程

数据库教程

SQL 教程

SQL 教程
SQLite 教程

SQLite 教程
MySQL 教程

MySQL 教程
PL/SQL 教程

PL/SQL 教程
MongoDB 教程

MongoDB 教程

图形图像教程

OpenCV 教程

OpenCV 教程

办公软件教程

Excel 教程

Excel 教程

Linux教程

Linux命令全集

Linux命令全集
Linux内核API

Linux内核API
LVGL 教程

LVGL 教程

计算机教程

操作系统 教程

操作系统 教程
计算机网络 教程

计算机网络 教程
C语言 教程

C语言 教程
C++ 教程

C++ 教程
Swift 教程

Swift 教程

大数据教程

Hadoop 教程

Hadoop 教程
Spark 教程

Spark 教程
Scala 教程

Scala 教程

开发工具教程

Git 教程

Git 教程
Jenkins 教程

Jenkins 教程
ChatGPT 教程

ChatGPT 教程
IntelliJ 教程

IntelliJ 教程

Android 精选笔记