添加国际化支持

app/build.gradle

@@ -1,12 +1,12 @@
 apply plugin: 'com.android.application'
-
+apply plugin: 'multi-languages'
 android {
     compileSdkVersion 29
     buildToolsVersion "29.0.3"
 
     defaultConfig {
         applicationId "com.community.pocket"
-        minSdkVersion 14
+        minSdkVersion 15
         targetSdkVersion 29
         versionCode 1
         versionName "1.0"
@@ -26,12 +26,16 @@ android {
 dependencies {
     implementation fileTree(dir: 'libs', include: ['*.jar'])
 
-    implementation 'androidx.appcompat:appcompat:1.0.2'
+    implementation 'androidx.appcompat:appcompat:1.1.0'
-    implementation 'com.google.android.material:material:1.0.0'
+    implementation 'com.google.android.material:material:1.1.0'
     implementation 'androidx.annotation:annotation:1.1.0'
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
-    implementation 'androidx.lifecycle:lifecycle-extensions:2.0.0'
+    implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
-    testImplementation 'junit:junit:4.12'
+    testImplementation 'junit:junit:4.13'
     androidTestImplementation 'androidx.test.ext:junit:1.1.1'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
+
+    implementation 'com.github.jokar:multi-languages:0.0.8'
+    implementation 'org.xutils:xutils:3.8.5'
+    implementation 'com.squareup.okhttp3:okhttp:4.4.1'
 }

app/src/main/AndroidManifest.xml

@@ -8,7 +8,9 @@
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
-        android:theme="@style/AppTheme">
+        android:theme="@style/AppTheme"
+        android:name=".util.InitApp"
+        android:fullBackupContent="@xml/backup_descriptor">
         <activity
             android:name=".ui.login.LoginActivity"
             android:label="@string/app_name">

app/src/main/assets/config.properties

@@ -0,0 +1,2 @@
+#登陆表单密码长度
+password.length=5

app/src/main/java/com/community/pocket/data/LoginDataSource.java

@@ -6,6 +6,7 @@ import java.io.IOException;
 
 /**
  * Class that handles authentication w/ login credentials and retrieves user information.
+ * 该类处理身份验证w/登录凭据并检索用户信息。
  */
 public class LoginDataSource {
 
@@ -19,11 +20,11 @@ public class LoginDataSource {
                             "Jane Doe");
             return new Result.Success<>(fakeUser);
         } catch (Exception e) {
-            return new Result.Error(new IOException("Error logging in", e));
+            return new Result.Error<>(new IOException("Error logging in", e), LoggedInUser.class);
         }
     }
 
-    public void logout() {
+    void logout() {
         // TODO: revoke authentication
     }
 }

app/src/main/java/com/community/pocket/data/LoginRepository.java

@@ -5,6 +5,8 @@ import com.community.pocket.data.model.LoggedInUser;
 /**
  * Class that requests authentication and user information from the remote data source and
  * maintains an in-memory cache of login status and user credentials information.
+ *  该类请求来自远程数据源的身份验证和用户信息
+ *  在内存中保存登录状态和用户凭证信息。
  */
 public class LoginRepository {
 

app/src/main/java/com/community/pocket/data/Result.java

@@ -1,13 +1,17 @@
 package com.community.pocket.data;
 
+import org.jetbrains.annotations.NotNull;
+
 /**
  * A generic class that holds a result success w/ data or an error exception.
+ * 一个泛型类，它持有一个结果成功w/数据或一个错误异常。
  */
 public class Result<T> {
     // hide the private constructor to limit subclass types (Success, Error)
     private Result() {
     }
 
+    @NotNull
     @Override
     public String toString() {
         if (this instanceof Result.Success) {
@@ -21,10 +25,10 @@ public class Result<T> {
     }
 
     // Success sub-class
-    public final static class Success<T> extends Result {
+    public final static class Success<T> extends Result<T> {
         private T data;
 
-        public Success(T data) {
+        Success(T data) {
             this.data = data;
         }
 
@@ -34,15 +38,21 @@ public class Result<T> {
     }
 
     // Error sub-class
-    public final static class Error extends Result {
+    final static class Error<T> extends Result<T> {
         private Exception error;
+        private Class<T> c;
 
-        public Error(Exception error) {
+        Error(Exception error, Class<T> c) {
             this.error = error;
+            this.c = c;
         }
 
-        public Exception getError() {
+        Exception getError() {
             return this.error;
         }
+
+        public Class<T> getC() {
+            return c;
+        }
     }
 }

app/src/main/java/com/community/pocket/data/adapter/LocaleAdapter.java

@@ -0,0 +1,58 @@
+package com.community.pocket.data.adapter;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.BaseAdapter;
+import android.widget.TextView;
+
+import com.community.pocket.util.LocaleType;
+
+import org.xutils.view.annotation.ViewInject;
+import org.xutils.x;
+
+public class LocaleAdapter extends BaseAdapter {
+    private LayoutInflater inflater;
+
+    public LocaleAdapter(LayoutInflater inflater) {
+        this.inflater = inflater;
+    }
+
+    @Override
+    public int getCount() {
+        return LocaleType.values().length;
+    }
+
+    @Override
+    public Object getItem(int position) {
+        return LocaleType.getLocale(position);
+    }
+
+    @Override
+    public long getItemId(int position) {
+        return position;
+    }
+
+    @Override
+    public View getView(int position, View convertView, ViewGroup parent) {
+        ViewHolder viewHolder;
+        if (convertView == null) {
+            convertView = inflater.inflate(android.R.layout.simple_list_item_1, null);
+            viewHolder = new ViewHolder();
+            //ViewHolder注解
+            x.view().inject(viewHolder, convertView);
+            convertView.setTag(viewHolder);
+        } else {
+            viewHolder = (ViewHolder) convertView.getTag();
+        }
+        viewHolder.childName.setText(convertView.getResources().getText(LocaleType.getLocale(position).getResId()));
+        return convertView;
+    }
+
+    private class ViewHolder {
+        @ViewInject(android.R.id.text1)//加载item的控件
+                TextView childName;
+    }
+
+
+}

app/src/main/java/com/community/pocket/data/model/LoggedInUser.java

@@ -2,6 +2,7 @@ package com.community.pocket.data.model;
 
 /**
  * Data class that captures user information for logged in users retrieved from LoginRepository
+ * 从LoginRepository检索的已登录用户捕获用户信息的数据类
  */
 public class LoggedInUser {
 

app/src/main/java/com/community/pocket/ui/BaseActivity.java

@@ -0,0 +1,22 @@
+package com.community.pocket.ui;
+
+import android.content.Context;
+import android.os.Bundle;
+
+import androidx.annotation.Nullable;
+import androidx.appcompat.app.AppCompatActivity;
+
+import org.xutils.x;
+
+public abstract class BaseActivity extends AppCompatActivity {
+    @Override
+    protected void attachBaseContext(Context newBase) {
+        super.attachBaseContext(newBase);
+    }
+
+    @Override
+    protected void onCreate(@Nullable Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        x.view().inject(this);//加载布局,控件
+    }
+}

app/src/main/java/com/community/pocket/ui/MainActivity.java

@@ -0,0 +1,8 @@
+package com.community.pocket.ui;
+
+import android.annotation.SuppressLint;
+
+@SuppressLint("Registered")
+public class MainActivity extends BaseActivity {
+
+}

app/src/main/java/com/community/pocket/ui/login/LoggedInUserView.java

@@ -2,6 +2,7 @@ package com.community.pocket.ui.login;
 
 /**
  * Class exposing authenticated user details to the UI.
+ * 类向UI公开已验证的用户详细信息。
  */
 class LoggedInUserView {
     private String displayName;

app/src/main/java/com/community/pocket/ui/login/LoginActivity.java

@@ -1,47 +1,76 @@
 package com.community.pocket.ui.login;
 
 import android.app.Activity;
-
+import android.content.Context;
-import androidx.lifecycle.Observer;
+import android.content.Intent;
-import androidx.lifecycle.ViewModelProviders;
-
 import android.os.Bundle;
-
-import androidx.annotation.Nullable;
-import androidx.annotation.StringRes;
-import androidx.appcompat.app.AppCompatActivity;
-
 import android.text.Editable;
 import android.text.TextWatcher;
 import android.view.KeyEvent;
+import android.view.LayoutInflater;
 import android.view.View;
 import android.view.inputmethod.EditorInfo;
+import android.widget.AdapterView;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.ProgressBar;
+import android.widget.Spinner;
 import android.widget.TextView;
 import android.widget.Toast;
 
+import androidx.annotation.Nullable;
+import androidx.annotation.StringRes;
+import androidx.lifecycle.Observer;
+import androidx.lifecycle.ViewModelProvider;
+
 import com.community.pocket.R;
-import com.community.pocket.ui.login.LoginViewModel;
+import com.community.pocket.data.adapter.LocaleAdapter;
-import com.community.pocket.ui.login.LoginViewModelFactory;
+import com.community.pocket.ui.BaseActivity;
+import com.community.pocket.util.LocalManageUtil;
+import com.community.pocket.util.LocaleType;
+import com.community.pocket.util.PropertiesUtil;
+import com.community.pocket.util.SPUtil;
+
+import org.xutils.view.annotation.ContentView;
+import org.xutils.view.annotation.ViewInject;
+
+/**
+ * 登陆
+ */
 
-public class LoginActivity extends AppCompatActivity {
+@ContentView(R.layout.activity_login)
+public class LoginActivity extends BaseActivity {
 
     private LoginViewModel loginViewModel;
 
+    //选择语言
+    @ViewInject(R.id.selectLang)
+    private Spinner spinner;
+
+    //用户名
+    @ViewInject(R.id.username)
+    private EditText usernameEditText;
+
+    //密码
+    @ViewInject(R.id.password)
+    private EditText passwordEditText;
+
+    //登录按钮
+    @ViewInject(R.id.login)
+    private Button loginButton;
+
+    //进度条
+    @ViewInject(R.id.loading)
+    private ProgressBar loadingProgressBar;
+
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_login);
+//        setContentView(R.layout.activity_login);
-        loginViewModel = ViewModelProviders.of(this, new LoginViewModelFactory())
-                .get(LoginViewModel.class);
 
-        final EditText usernameEditText = findViewById(R.id.username);
+        loginViewModel = new ViewModelProvider(this, new LoginViewModelFactory()).get(LoginViewModel.class);
-        final EditText passwordEditText = findViewById(R.id.password);
-        final Button loginButton = findViewById(R.id.login);
-        final ProgressBar loadingProgressBar = findViewById(R.id.loading);
 
+        //监听数据校验状态
         loginViewModel.getLoginFormState().observe(this, new Observer<LoginFormState>() {
             @Override
             public void onChanged(@Nullable LoginFormState loginFormState) {
@@ -53,11 +82,12 @@ public class LoginActivity extends AppCompatActivity {
                     usernameEditText.setError(getString(loginFormState.getUsernameError()));
                 }
                 if (loginFormState.getPasswordError() != null) {
-                    passwordEditText.setError(getString(loginFormState.getPasswordError()));
+                    passwordEditText.setError(getString(loginFormState.getPasswordError(), PropertiesUtil.getIntValue("password.length")));
                 }
             }
         });
 
+        //监听登陆请求结果
         loginViewModel.getLoginResult().observe(this, new Observer<LoginResult>() {
             @Override
             public void onChanged(@Nullable LoginResult loginResult) {
@@ -74,10 +104,31 @@ public class LoginActivity extends AppCompatActivity {
                 setResult(Activity.RESULT_OK);
 
                 //Complete and destroy login activity once successful
-                finish();
+//                finish();
             }
         });
 
+
+        //加载语言选项
+        spinner.setAdapter(new LocaleAdapter(LayoutInflater.from(this)));
+        spinner.setSelection(SPUtil.getInstance(getBaseContext()).getSelectLanguage());
+        //选择语言事件
+        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
+            @Override
+            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
+                if (SPUtil.getInstance(getBaseContext()).getSelectLanguage() != position) {
+                    LocaleType locale = LocaleType.getLocale(position);
+                    selectLanguage(locale);
+                }
+            }
+
+            @Override
+            public void onNothingSelected(AdapterView<?> parent) {
+
+            }
+        });
+
+//        监听用户密码文本输入框内容改变
         TextWatcher afterTextChangedListener = new TextWatcher() {
             @Override
             public void beforeTextChanged(CharSequence s, int start, int count, int after) {
@@ -95,23 +146,31 @@ public class LoginActivity extends AppCompatActivity {
                         passwordEditText.getText().toString());
             }
         };
+
+        //添加监听器到组件
         usernameEditText.addTextChangedListener(afterTextChangedListener);
         passwordEditText.addTextChangedListener(afterTextChangedListener);
+
+        //监听密码软键盘输入
         passwordEditText.setOnEditorActionListener(new TextView.OnEditorActionListener() {
 
             @Override
             public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
+                //点击完成执行登陆操作
                 if (actionId == EditorInfo.IME_ACTION_DONE) {
                     loginViewModel.login(usernameEditText.getText().toString(),
                             passwordEditText.getText().toString());
                 }
+                //默认不执行任何操作
                 return false;
             }
         });
 
+        //登录按钮触发登录请求操作
         loginButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
+                //显示登录请求处理进度
                 loadingProgressBar.setVisibility(View.VISIBLE);
                 loginViewModel.login(usernameEditText.getText().toString(),
                         passwordEditText.getText().toString());
@@ -119,13 +178,36 @@ public class LoginActivity extends AppCompatActivity {
         });
     }
 
+    //登陆成功信息
     private void updateUiWithUser(LoggedInUserView model) {
         String welcome = getString(R.string.welcome) + model.getDisplayName();
         // TODO : initiate successful logged in experience
         Toast.makeText(getApplicationContext(), welcome, Toast.LENGTH_LONG).show();
     }
 
+    //登陆错误信息
     private void showLoginFailed(@StringRes Integer errorString) {
         Toast.makeText(getApplicationContext(), errorString, Toast.LENGTH_SHORT).show();
     }
+
+    /**
+     * 选择语言
+     *
+     * @param locale 语言
+     */
+    private void selectLanguage(LocaleType locale) {
+        LocalManageUtil.saveSelectLanguage(this, locale.getType());
+        reStart(this);
+    }
+
+    /**
+     * 重启
+     *
+     * @param context 应用上下文
+     */
+    public static void reStart(Context context) {
+        Intent intent = new Intent(context, LoginActivity.class);
+        intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK | Intent.FLAG_ACTIVITY_NEW_TASK);
+        context.startActivity(intent);
+    }
 }

app/src/main/java/com/community/pocket/ui/login/LoginFormState.java

@@ -4,6 +4,7 @@ import androidx.annotation.Nullable;
 
 /**
  * Data validation state of the login form.
+ * 登陆表单的数据校验
  */
 class LoginFormState {
     @Nullable

app/src/main/java/com/community/pocket/ui/login/LoginResult.java

@@ -4,6 +4,7 @@ import androidx.annotation.Nullable;
 
 /**
  * Authentication result : success (user details) or error message.
+ * 验证结果:成功(用户详细信息)或错误消息。
  */
 class LoginResult {
     @Nullable

app/src/main/java/com/community/pocket/ui/login/LoginViewModel.java

@@ -1,20 +1,26 @@
 package com.community.pocket.ui.login;
 
+import android.util.Patterns;
+
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 import androidx.lifecycle.ViewModel;
 
-import android.util.Patterns;
+import com.community.pocket.R;
-
 import com.community.pocket.data.LoginRepository;
 import com.community.pocket.data.Result;
 import com.community.pocket.data.model.LoggedInUser;
-import com.community.pocket.R;
 
+/**
+ * 登陆表单数据
+ */
 public class LoginViewModel extends ViewModel {
 
+    //登陆表单校验信息
     private MutableLiveData<LoginFormState> loginFormState = new MutableLiveData<>();
+    //登陆结果
     private MutableLiveData<LoginResult> loginResult = new MutableLiveData<>();
+    //登陆请求数据源
     private LoginRepository loginRepository;
 
     LoginViewModel(LoginRepository loginRepository) {
@@ -29,6 +35,7 @@ public class LoginViewModel extends ViewModel {
         return loginResult;
     }
 
+    //登陆
     public void login(String username, String password) {
         // can be launched in a separate asynchronous job
         Result<LoggedInUser> result = loginRepository.login(username, password);
@@ -41,7 +48,8 @@ public class LoginViewModel extends ViewModel {
         }
     }
 
-    public void loginDataChanged(String username, String password) {
+    //登陆表单数据变化触发数据校验
+    void loginDataChanged(String username, String password) {
         if (!isUserNameValid(username)) {
             loginFormState.setValue(new LoginFormState(R.string.invalid_username, null));
         } else if (!isPasswordValid(password)) {
@@ -52,6 +60,7 @@ public class LoginViewModel extends ViewModel {
     }
 
     // A placeholder username validation check
+    //用户名校验
     private boolean isUserNameValid(String username) {
         if (username == null) {
             return false;
@@ -64,6 +73,7 @@ public class LoginViewModel extends ViewModel {
     }
 
     // A placeholder password validation check
+    //密码校验
     private boolean isPasswordValid(String password) {
         return password != null && password.trim().length() > 5;
     }

app/src/main/java/com/community/pocket/ui/login/LoginViewModelFactory.java

@@ -1,8 +1,8 @@
 package com.community.pocket.ui.login;
 
+import androidx.annotation.NonNull;
 import androidx.lifecycle.ViewModel;
 import androidx.lifecycle.ViewModelProvider;
-import androidx.annotation.NonNull;
 
 import com.community.pocket.data.LoginDataSource;
 import com.community.pocket.data.LoginRepository;
@@ -10,6 +10,8 @@ import com.community.pocket.data.LoginRepository;
 /**
  * ViewModel provider factory to instantiate LoginViewModel.
  * Required given LoginViewModel has a non-empty constructor
+ * ViewModel提供程序工厂来实例化LoginViewModel。
+ * 给定的LoginViewModel有一个非空的构造函数
  */
 public class LoginViewModelFactory implements ViewModelProvider.Factory {
 

app/src/main/java/com/community/pocket/util/InitApp.java

@@ -0,0 +1,50 @@
+package com.community.pocket.util;
+
+import android.app.Application;
+import android.content.Context;
+import android.content.res.Configuration;
+
+import com.github.jokar.multilanguages.library.LanguageLocalListener;
+import com.github.jokar.multilanguages.library.MultiLanguage;
+
+import org.jetbrains.annotations.NotNull;
+import org.xutils.x;
+
+import java.util.Locale;
+
+/**
+ * 应用启动初始化
+ */
+public class InitApp extends Application {
+    @Override
+    public void onCreate() {
+        super.onCreate();
+        //框架初始化
+        x.Ext.init(this);
+
+        MultiLanguage.init(new LanguageLocalListener() {
+            @Override
+            public Locale getSetLanguageLocale(Context context) {
+                //返回自己本地保存选择的语言设置
+                return LocalManageUtil.getSetLanguageLocale(context);
+            }
+        });
+        MultiLanguage.setApplicationLanguage(this);
+    }
+
+    @Override
+    protected void attachBaseContext(Context base) {
+        //第一次进入app时保存系统选择语言(为了选择随系统语言时使用，如果不保存，切换语言后就拿不到了）
+        LocalManageUtil.saveSystemCurrentLanguage(base);
+        super.attachBaseContext(MultiLanguage.setLocal(base));
+    }
+
+    @Override
+    public void onConfigurationChanged(@NotNull Configuration newConfig) {
+        super.onConfigurationChanged(newConfig);
+        //用户在系统设置页面切换语言时保存系统选择语言(为了选择随系统语言时使用，如果不保存，切换语言后就拿不到了）
+        LocalManageUtil.saveSystemCurrentLanguage(getApplicationContext(), newConfig);
+        MultiLanguage.onConfigurationChanged(getApplicationContext());
+    }
+
+}

app/src/main/java/com/community/pocket/util/LocalManageUtil.java

@@ -0,0 +1,65 @@
+package com.community.pocket.util;
+
+import android.content.Context;
+import android.content.res.Configuration;
+
+import com.github.jokar.multilanguages.library.MultiLanguage;
+
+import java.util.Locale;
+
+//界面语言管理工具类
+public class LocalManageUtil {
+    private static final String TAG = "LocalManageUtil";
+
+    /**
+     * 获取系统的locale
+     *
+     * @return Locale对象
+     */
+    private static Locale getSystemLocale(Context context) {
+        return SPUtil.getInstance(context).getSystemCurrentLocal();
+    }
+
+    public static String getSelectLanguage(Context context) {
+        int type = SPUtil.getInstance(context).getSelectLanguage();
+        return context.getString(LocaleType.getLocale(type).getResId());
+    }
+
+    /**
+     * 获取选择的语言设置
+     *
+     * @param context 应用上下文
+     */
+    static Locale getSetLanguageLocale(Context context) {
+
+        int type = SPUtil.getInstance(context).getSelectLanguage();
+        if (type == 0) {
+            return getSystemLocale(context);
+        } else {
+            return LocaleType.getLocale(type).getLocale();
+        }
+    }
+
+
+    static void saveSystemCurrentLanguage(Context context) {
+        SPUtil.getInstance(context).setSystemCurrentLocal(MultiLanguage.getSystemLocal(context));
+    }
+
+    /**
+     * 保存系统语言
+     *
+     * @param context   应用上下文
+     * @param newConfig 刷新系统配置
+     */
+    static void saveSystemCurrentLanguage(Context context, Configuration newConfig) {
+
+        SPUtil.getInstance(context).setSystemCurrentLocal(MultiLanguage.getSystemLocal(newConfig));
+    }
+
+    public static void saveSelectLanguage(Context context, int select) {
+        SPUtil.getInstance(context).saveLanguage(select);
+        MultiLanguage.setApplicationLanguage(context);
+    }
+
+
+}

app/src/main/java/com/community/pocket/util/LocaleType.java

@@ -0,0 +1,46 @@
+package com.community.pocket.util;
+
+import com.community.pocket.R;
+
+import java.util.Locale;
+
+//语言类型
+public enum LocaleType {
+    auto(Locale.ENGLISH, 0, R.string.language_auto),
+    chs(Locale.CHINA, 1, R.string.language_chs),
+    en(Locale.ENGLISH, 2, R.string.language_en);
+
+    //语言
+    private Locale locale;
+    //类型值
+    private int type;
+    //选项名对应的资源id
+    private int resId;
+
+    public Locale getLocale() {
+        return locale;
+    }
+
+    public int getType() {
+        return type;
+    }
+
+    public int getResId() {
+        return resId;
+    }
+
+    LocaleType(Locale locale, int type, int resId) {
+        this.locale = locale;
+        this.type = type;
+        this.resId = resId;
+    }
+
+    public static LocaleType getLocale(int type) {
+        for (LocaleType t : LocaleType.values()) {
+            if (t.type == type) {
+                return t;
+            }
+        }
+        return LocaleType.auto;
+    }
+}

app/src/main/java/com/community/pocket/util/PropertiesUtil.java

@@ -0,0 +1,48 @@
+package com.community.pocket.util;
+
+import java.io.InputStream;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+
+//读取配置文件工具类
+public class PropertiesUtil {
+
+    private static Properties properties;
+
+    private final static Map<String, String> values = new HashMap<>();
+
+    //    文件路径
+    private static final String filePath = "/assets/config.properties";
+
+    static {
+        properties = new Properties();
+        try {
+            InputStream is = PropertiesUtil.class.getResourceAsStream(filePath);
+            properties.load(is);
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+    }
+
+    //获取字符串配置
+    private static String getValue(String key) {
+        if (values.containsKey(key)) {
+            return values.get(key);
+        } else {
+            String value = properties.getProperty(key);
+            values.put(key, value);
+            return value;
+        }
+    }
+
+    //    获取整数配置
+    public static int getIntValue(String key) {
+        String value = getValue(key);
+        if (value.matches("\\d+")) {
+            return Integer.parseInt(value);
+        } else {
+            throw new RuntimeException("值转换异常！无法把" + key + "=" + value + "转化成整数");
+        }
+    }
+}

app/src/main/java/com/community/pocket/util/SPUtil.java

@@ -0,0 +1,56 @@
+package com.community.pocket.util;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+
+import java.util.Locale;
+
+/**
+ * 界面语言配置读写
+ */
+public class SPUtil {
+
+    private final String SP_NAME = "language_setting";
+    private final String TAG_LANGUAGE = "language_select";
+    private static volatile SPUtil instance;
+
+    private final SharedPreferences mSharedPreferences;
+
+    private Locale systemCurrentLocal = Locale.ENGLISH;
+
+
+    private SPUtil(Context context) {
+        mSharedPreferences = context.getSharedPreferences(SP_NAME, Context.MODE_PRIVATE);
+    }
+
+
+    void saveLanguage(int select) {
+        SharedPreferences.Editor edit = mSharedPreferences.edit();
+        edit.putInt(TAG_LANGUAGE, select);
+        edit.apply();
+    }
+
+    public int getSelectLanguage() {
+        return mSharedPreferences.getInt(TAG_LANGUAGE, 0);
+    }
+
+
+    Locale getSystemCurrentLocal() {
+        return systemCurrentLocal;
+    }
+
+    void setSystemCurrentLocal(Locale local) {
+        systemCurrentLocal = local;
+    }
+
+    public static SPUtil getInstance(Context context) {
+        if (instance == null) {
+            synchronized (SPUtil.class) {
+                if (instance == null) {
+                    instance = new SPUtil(context);
+                }
+            }
+        }
+        return instance;
+    }
+}

app/src/main/res/layout/activity_login.xml

@@ -24,7 +24,8 @@
         android:selectAllOnFocus="true"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+        app:layout_constraintTop_toTopOf="parent"
+        android:autofillHints="@string/AUTOFILL_HINT_USERNAME" />
 
     <EditText
         android:id="@+id/password"
@@ -41,7 +42,8 @@
         android:selectAllOnFocus="true"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@+id/username" />
+        app:layout_constraintTop_toBottomOf="@+id/username"
+        android:autofillHints="@string/AUTOFILL_HINT_PASSWORD" />
 
     <Button
         android:id="@+id/login"
@@ -75,4 +77,24 @@
         app:layout_constraintStart_toStartOf="@+id/password"
         app:layout_constraintTop_toTopOf="parent"
         app:layout_constraintVertical_bias="0.3" />
+
+    <Spinner
+        android:id="@+id/selectLang"
+        android:layout_width="250dp"
+        android:layout_height="wrap_content"
+        android:gravity="center"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <TextView
+        android:id="@+id/textView"
+        android:layout_width="115dp"
+        android:layout_height="wrap_content"
+        android:layout_marginEnd="4dp"
+        android:layout_marginRight="4dp"
+        android:gravity="center"
+        android:text="@string/language_choose"
+        app:layout_constraintBottom_toBottomOf="@+id/selectLang"
+        app:layout_constraintEnd_toStartOf="@+id/selectLang"
+        app:layout_constraintTop_toTopOf="@+id/selectLang" />
 </androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/values-en-rUS/strings.xml

@@ -7,6 +7,12 @@
     <string name="action_sign_in_short">Sign in</string>
     <string name="welcome">"Welcome !"</string>
     <string name="invalid_username">Not a valid username</string>
-    <string name="invalid_password">Password must be >5 characters</string>
+    <string name="invalid_password">Password must be >%1$s characters</string>
     <string name="login_failed">"Login failed"</string>
+    <string name="language_auto">system language</string>
+    <string name="language_chs">chs</string>
+    <string name="language_en">en</string>
+    <string name="language_choose">current language</string>
+    <string name="AUTOFILL_HINT_PASSWORD">password</string>
+    <string name="AUTOFILL_HINT_USERNAME">username</string>
 </resources>

app/src/main/res/values-zh-rCN/strings.xml

@@ -7,6 +7,12 @@
     <string name="action_sign_in_short">登陆</string>
     <string name="welcome">"欢迎 !"</string>
     <string name="invalid_username">用户名不合法</string>
-    <string name="invalid_password">密码至少5个字符</string>
+    <string name="invalid_password">密码必须大于%1$s个字符</string>
     <string name="login_failed">"登陆失败"</string>
+    <string name="language_auto">系统语言</string>
+    <string name="language_chs">简体中文</string>
+    <string name="language_en">英文</string>
+    <string name="language_choose">当前界面语言</string>
+    <string name="AUTOFILL_HINT_PASSWORD">password</string>
+    <string name="AUTOFILL_HINT_USERNAME">username</string>
 </resources>

app/src/main/res/values/strings.xml

@@ -7,6 +7,12 @@
     <string name="action_sign_in_short">Sign in</string>
     <string name="welcome">"Welcome !"</string>
     <string name="invalid_username">Not a valid username</string>
-    <string name="invalid_password">Password must be >5 characters</string>
+    <string name="invalid_password">Password must be >%1$s characters</string>
     <string name="login_failed">"Login failed"</string>
+    <string name="language_auto">system language</string>
+    <string name="language_chs">chs</string>
+    <string name="language_en">en</string>
+    <string name="language_choose">current language</string>
+    <string name="AUTOFILL_HINT_PASSWORD">password</string>
+    <string name="AUTOFILL_HINT_USERNAME">username</string>
 </resources>

app/src/main/res/xml/backup_descriptor.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<full-backup-content>
+    <include
+        domain="sharedpref"
+        path="." />
+</full-backup-content>

build.gradle

@@ -6,10 +6,11 @@ buildscript {
         maven { url 'https://maven.aliyun.com/repository/public/' }
         google()
         jcenter()
+//        maven { url 'https://dl.bintray.com/a10188755550/maven'}
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.6.1'
-        
+        classpath 'com.github.jokar:multi-languages.plugin:0.0.8'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files