Thing Translator
从 Android 应用程序使用 WebAPI2 服务。
引言
在我的教程的 第一部分 中，我们构建了一个 Web API，用于处理图像标注和翻译成不同的语言。现在我们将构建一个可以消费该 API 的 Android 应用。我们将实现的功能包括：
- 选择目标语言
- 从图库中选择图像或使用相机拍摄新照片
- 开启/关闭语音输出选项
使用代码
所有代码库都位于本文的代码部分。为了简单起见，我将仅突出显示代码的重要部分。
build.gradle
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
compile 'com.google.code.gson:gson:2.6.1'
compile 'com.android.support:support-v13:23.4.0'
compile 'com.android.support:appcompat-v7:23.4.0'
compile 'com.android.support:design:23.4.0'
compile 'com.squareup.retrofit2:retrofit:2.0.0'
compile 'com.squareup.retrofit2:converter-gson:2.0.0'
compile 'com.squareup.okhttp3:okhttp:3.4.1'
compile 'com.android.support.constraint:constraint-layout:1.0.0-alpha4'
testCompile 'junit:junit:4.12'
compile 'com.pixplicity.easyprefs:library:1.8.1@aar'
compile 'com.jakewharton:butterknife:8.4.0'
annotationProcessor 'com.jakewharton:butterknife-compiler:8.4.0'
}
我们将使用一些非常酷的 Java 库，使 Android 开发更加容易。
- easyprefs - 轻松访问 SharedPrefferences
- butterknife - 使 Views 声明更加容易
- retrofit - 使我们能够快速轻松地使用 REST API
activity_main - spinner View 具有在 spinner_item.xml 中定义的自定义布局
<Spinner
android:id="@+id/spinner"
android:layout_width="100dp"
android:layout_height="match_parent"
android:layout_marginBottom="16dp"
android:layout_weight="0.91"
android:gravity="bottom|right" />
<?xml version="1.0" encoding="utf-8"?>
<TextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="30dp"
android:textColor="@android:color/darker_gray"
android:textSize="24dp"
/>
ApiInterface.java - 这是我们 REST API 调用的接口。将我们在上一教程中构建的 API URL 放入 ENDPOINT 变量中。如您所见，在发出 POST 请求时仅使用 2 个参数
- 图像文件
- 语言代码
package thingtranslator2.jalle.com.thingtranslator2.Rest;
public interface ApiInterface {
String ENDPOINT = "YOUR-API-URL/api/";
@Multipart
@POST("upload")
Call<translation> upload(@Part("image\"; filename=\"pic.jpg\" ") RequestBody file, @Part("FirstName") RequestBody langCode1);
final OkHttpClient okHttpClient = new OkHttpClient.Builder()
.readTimeout(60, TimeUnit.SECONDS)
.connectTimeout(60, TimeUnit.SECONDS)
.build();
Retrofit retrofit = new Retrofit.Builder()
.baseUrl(ENDPOINT)
.client(okHttpClient)
.addConverterFactory(GsonConverterFactory.create())
.build();
}
翻译类
package thingtranslator2.jalle.com.thingtranslator2.Rest;
public class Translation {
public String Original;
public String Translation;
public String Error;
}
Tools - ImagePicker 此类用于从图库获取图像或从相机拍摄新照片。Tools - MarshMallowPermission 用于在 Android 6 上设置相机权限。
AndroidManifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="thingtranslator2.jalle.com.thingtranslator2">
<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<application
android:allowBackup="true"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
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>
</application>
</manifest>
MainActivity.java
public class MainActivity extends AppCompatActivity implements AdapterView.OnItemSelectedListener {
public
@BindView(R.id.txtTranslation)
TextView txtTranslation;
public
@BindView(R.id.spinner)
Spinner spinner;
public
@BindView(R.id.imgPhoto)
ImageButton imgPhoto;
public
@BindView(R.id.imgSpeaker)
ImageButton btnSpeaker;
public Boolean speakerOn, firstRun;
public TextToSpeech tts;
public List<string> languages = new ArrayList<string>();
public ArrayList<language> languageList = new ArrayList<language>();
public ArrayAdapter<language> spinnerArrayAdapter;
public Language selectedLanguage;
public static final int PICK_IMAGE_ID = 234; // the number doesn't matter
thingtranslator2.jalle.com.thingtranslator2.MarshMallowPermission marshMallowPermission = new thingtranslator2.jalle.com.thingtranslator2.MarshMallowPermission(this);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
ButterKnife.bind(this);
//init our Shared preferences helper
new Prefs.Builder()
.setContext(this)
.setMode(ContextWrapper.MODE_PRIVATE)
.setPrefsName(getPackageName())
.setUseDefaultSharedPreference(true)
.build();
// Prefs.clear();
firstRun = Prefs.getBoolean("firstRun", true);
spinner.setOnItemSelectedListener(this);
tts = new TextToSpeech(getApplicationContext(), new TextToSpeech.OnInitListener() {
@Override
public void onInit(int status) {
if (status != TextToSpeech.ERROR) {
fillSpinner();
}
}
});
if (firstRun) {
Prefs.putBoolean("firstRun", false);
Prefs.putBoolean("speakerOn", true);
Prefs.putString("langCode", "bs");
}
setSpeaker();
}
private void setSpeaker() {
int id = Prefs.getBoolean("speakerOn", false) ? R.drawable.ic_volume : R.drawable.ic_volume_off;
btnSpeaker.setImageBitmap(BitmapFactory.decodeResource(getResources(), id));
}
public void ToogleSpeaker(View v) {
Prefs.putBoolean("speakerOn", !Prefs.getBoolean("speakerOn", false));
setSpeaker();
Toast.makeText(getApplicationContext(), "Speech " + (Prefs.getBoolean("speakerOn", true) ? "On" : "Off"), Toast.LENGTH_SHORT);
}
private void fillSpinner() {
Iterator itr = tts.getAvailableLanguages().iterator();
while (itr.hasNext()) {
Locale item = (Locale) itr.next();
languageList.add(new Language(item.getDisplayName(), item.getLanguage()));
}
//Sort that array
Collections.sort(languageList, new Comparator<language>() {
@Override
public int compare(Language o1, Language o2) {
return o1.getlangCode().compareTo(o2.getlangCode());
}
});
spinnerArrayAdapter = new ArrayAdapter<language>(this, R.layout.spinner_item, languageList);
spinnerArrayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(spinnerArrayAdapter);
//Set the default language to bs- Bosnian
String def = Prefs.getString("langCode", "bs");
for (Language lang : languageList) {
if (lang.getlangCode().equals(def)) {
spinner.setSelection(languageList.indexOf(lang));
}
}
}
;
//Get image from Gallery or Camera
public void getImage(View v) {
if (!marshMallowPermission.checkPermissionForCamera()) {
marshMallowPermission.requestPermissionForCamera();
} else {
if (!marshMallowPermission.checkPermissionForExternalStorage()) {
marshMallowPermission.requestPermissionForExternalStorage();
} else {
Intent chooseImageIntent = thingtranslator2.jalle.com.thingtranslator2.ImagePicker.getPickImageIntent(getApplicationContext());
startActivityForResult(chooseImageIntent, PICK_IMAGE_ID);
}
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (data == null) return;
switch (requestCode) {
case PICK_IMAGE_ID:
Bitmap bitmap = thingtranslator2.jalle.com.thingtranslator2.ImagePicker.getImageFromResult(this, resultCode, data);
imgPhoto.setImageBitmap(null);
imgPhoto.setBackground(null);
imgPhoto.setImageBitmap(bitmap);
imgPhoto.invalidate();
imgPhoto.postInvalidate();
File file = null;
try {
file = savebitmap(bitmap, "pic.jpeg");
} catch (IOException e) {
e.printStackTrace();
}
uploadImage(file);
break;
default:
super.onActivityResult(requestCode, resultCode, data);
break;
}
}
private void uploadImage(File file) {
RequestBody body = RequestBody.create(MediaType.parse("image/*"), file);
RequestBody langCode1 = RequestBody.create(MediaType.parse("text/plain"), selectedLanguage.langCode);
final ProgressDialog progress = new ProgressDialog(this);
progress.setMessage("Processing image...");
progress.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progress.setIndeterminate(true);
progress.show();
ApiInterface mApiService = ApiInterface.retrofit.create(ApiInterface.class);
Call<translation> mService = mApiService.upload(body, langCode1);
mService.enqueue(new Callback<translation>() {
@Override
public void onResponse(Call<translation> call, Response<translation> response) {
progress.hide();
Translation result = response.body();
txtTranslation.setText(result.Translation);
txtTranslation.invalidate();
if (Prefs.getBoolean("speakerOn", true)) {
tts.speak(result.Translation, TextToSpeech.QUEUE_FLUSH, null);
}
}
@Override
public void onFailure(Call<translation> call, Throwable t) {
call.cancel();
progress.hide();
Toast.makeText(getApplicationContext(), "Error: " + t.getMessage(), Toast.LENGTH_LONG).show();
}
});
}
public static File savebitmap(Bitmap bmp, String fName) throws IOException {
ByteArrayOutputStream bytes = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.JPEG, 60, bytes);
File f = new File(Environment.getExternalStorageDirectory()
+ File.separator + fName);
f.createNewFile();
FileOutputStream fo = new FileOutputStream(f);
fo.write(bytes.toByteArray());
fo.close();
return f;
}
@Override
public void onItemSelected(AdapterView parent, View view, int position, long id) {
selectedLanguage = (Language) spinner.getSelectedItem();
// langCode = languages.get(position);
tts.setLanguage(Locale.forLanguageTag(selectedLanguage.langCode));
Prefs.putString("langCode", selectedLanguage.langCode);
}
@Override
public void onNothingSelected(AdapterView parent) {
}
}
本教程的最终结果是一个如下所示的应用程序。请记住，您的 WebAPI 服务需要启动并运行才能使所有这些工作正常。
关注点
有很多方法可以改进和升级此应用程序。我的一个想法是可以在相机实时预览期间完成图像标注。打开预览窗口后，我们可以每 5-10 秒调用一次 API，并实时标注我们通过相机看到的内容。
一个缺点是它会消耗大量的带宽，并且请记住，Google API Vision 和大多数其他 API 不是免费的。当请求超过允许的配额时，您需要为 API 使用付费。
编码愉快！