JOONRYANG..forever: 6월 2017

2017년 6월 4일 일요일

[STUDY] Android "shinebutton" 라이브러리 소개

[목차]======================================================

1. Android ShineButton 소개

2. ShineButton 라이브러리 정보

1) 라이브러리 다운로드 주소

2) Installation and usage

3) License

===========================================================

1. Android ShineButton 소개

버튼을 클릭하면 폭죽이 터지는 듯한 효과를 제공하는 라이브러리로 아래 그림 같은 효과를 제공한다.

This is a UI lib for Android. Effects like shining.

2. ShineButton 라이브러리 정보

1) 라이브러리 다운로드 주소

https://github.com/ChadCSong/ShineButton

2) Installation and usage

Maven

<groupId>com.sackcentury</groupId>

<artifactId>shinebutton</artifactId>

</dependency>

Gradle

buildscript {

repositories {

mavenCentral()

}

dependencies {

compile 'com.sackcentury:shinebutton:0.1.7'

}

Usage

shineButton = (ShineButton) findViewById(R.id.shine_button);

shineButton.init(activity);

ShineButton shineButtonJava = new ShineButton(this);

shineButtonJava.setBtnColor(Color.GRAY);

shineButtonJava.setBtnFillColor(Color.RED);

shineButtonJava.setShapeResource(R.raw.heart);

shineButtonJava.setAllowRandomColor(true);

LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(100, 100);

shineButtonJava.setLayoutParams(layoutParams);

if (linearLayout != null) {

linearLayout.addView(shineButtonJava);

}

iOS lib fave-button Android implement. FaveButton was inspired by Twitter’s Like Heart Animation;

3) License

The MIT License (MIT)

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all

copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

SOFTWARE.

출처 : 인터넷에서 검색하여 필요한 정보를 다양한 사이트에서 종합하여 작성된 것입니다. 많은 사이트 내용을 종합하여 공부하여 작성하다보니 일일이 나열하지 못하였습니다. ㅈㅅ(_ _) 이글은 자유롭게 퍼 가셔서 도움이 되었으면 좋겠습니다. 감사합니다.

[STUDY] Android "android-flowlayout" 라이브러리 소개

[목차]===========================================================

1. android-flowlayout 소개

2. android-flowlayout 라이브러리 정보

1) 라이브러리 다운로드 주소

2) Installation and usage

3) Detailed parameters

4) License

================================================================

1. android-flowlayout 소개

자바 GUI에는 FlowLayout이라는 유용한 레이아웃이 있는데, 안드로이드에는 없어서 만들어진 오픈소스입니다.

UI를 배치하다가 공간이 부족한 경우, 줄바꿈하여 다음행에서 계속 UI를 배치하는 레이아웃임

2. android-flowlayout 라이브러리 정보

1) 라이브러리 다운로드 주소

https://github.com/ApmeM/android-flowlayout

2) Installation and usage

Add it as dependency in Gradle as : compile 'org.apmem.tools:layouts:1.10@aar'

Or maven

<groupId>org.apmem.tools</groupId>

<artifactId>layouts</artifactId>

<scope>provided</scope>

</dependency>

Add the following xml code into your layout/something.xml:

<org.apmem.tools.layouts.FlowLayout

xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

</org.apmem.tools.layouts.FlowLayout>

Android gravity now supported (in combination with elements weight):

f:weightDefault="1.0"

android:gravity="fill"

To override default spacing between elements use default android margins in the child View element:

android:layout_marginTop="32dip"

android:layout_marginRight="32dip"

Also if you need to break line before some object even if there is enough space for it in the previous line - use the following LayoutParameter in the child view element:

f:layout_newLine="true"

3) Detailed parameters

android:orientation - line direction. Use one of the following values:

* horizontal - line will be in horizontal direction, linebreak will create new line

* vertical - line will be in vertical direction, linebreak will create new column

android:gravity - standart android gravity supported

debugDraw - draw debug information

weightDefault - default weight value for child elements. Used to fill line in case of Gravity.FILL_HORIZONTAL | Gravity.FILL_VERTICAL
layoutDirection - direction of inner child elements:

* ltr - left to right direction

* rtl - right to left direction

android:layout_margin* - override default spacings
android:layout_gravity - standart aandroid gravity supported

* layout_weight - weight of the element. If not specified "layout.defaultWight" is used.

layout_newLine - brake line before current element even if there is enough place in the current line.

4) License

Copyrights

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

[STUDY] Android Shortcut & Badge (ShortcutBadger 라이브러리 소개)

[목차]======================================================

1. Android 아이콘 뱃지 관련 라이브러리

1) 오픈소스 주소

2) 사용법
2. Android 아이콘 뱃지 관련된 게시글 참고(주소 펴옴)

===========================================================

1. Android 아이콘 뱃지 관련 라이브러리

1) 오픈소스 주소

https://github.com/leolin310148/ShortcutBadger

2) 사용법

Add mavenCentral to your build script.

repositories {

mavenCentral()

}

Add dependencies for ShortcutBadger, it's available from maven now.

dependencies {

compile "me.leolin:ShortcutBadger:1.1.16@aar"

}

Add the codes below:

int badgeCount = 1;

ShortcutBadger.applyCount(context, badgeCount); //for 1.1.4+

ShortcutBadger.with(getApplicationContext()).count(badgeCount); //for 1.1.3

If you want to remove the badge

ShortcutBadger.removeCount(context); //for 1.1.4+

ShortcutBadger.with(getApplicationContext()).remove(); //for 1.1.3

ShortcutBadger.applyCount(context, 0); //for 1.1.4+

ShortcutBadger.with(getApplicationContext()).count(0); //for 1.1.3

2. Android 아이콘 뱃지 관련된 게시글 참고(주소 펴옴)

[안드로이드 아이콘 뱃지 완전분해]

=> Android 아이콘 뱃지에 대한 분석 및 기본 개발에 대한 의견 참고

https://medium.com/marojuns-android/%EC%95%88%EB%93%9C%EB%A1%9C%EC%9D%B4%EB%93%9C-%EC%95%84%EC%9D%B4%EC%BD%98-%EB%B1%83%EC%A7%80-%EC%99%84%EC%A0%84%EB%B6%84%ED%95%B4-c27028014e4d

[STUDY] Butter Knife (버터나이프 - 특징 / 사용법 / 기능 / 라이센스 등)

[ButterKnife 목차]

====================================

1. ButterKnife의 특징

2. 사용법1) Gradle 파일 설정
2) ButterKnife 라이브러리 bind

3. 기능1) View를 담을 변수를 선언

2) View Lists
3) Listener Binding (onClickListener)
4) Resource Binding
5) Non-Activity Binding
6) Binding Reset
7) Adapter
8) Multi-Method Listeners
9) Optional Bindings
10) ETC

4. License

====================================

1. ButterKnife의 특징

1) 필드나 메소드를 안드로이드 뷰에 어노테이션(@)을 이용하여 편하게 접근할 수 있도록 도와주는 안드로이드 라이브러리

=> ButterKnife 공식 홈페이지 https://github.com/JakeWharton/butterknife

2) 다수의 안드로이드 개발자들과 협업할때 View, Resource를 바인딩 하는 convention을 제공

=> 코드의 가독성 및 View ID 검색 및 효율성을 높여주는데 참 좋은것 같음

※ 자바 어노테이션(Annotation, @)이란?

http://alltogetherwe.tistory.com/14

2. 사용법

1) Gradle 파일 설정

build.gradle 파일을 열어 dependencies를 추가해주시면 라이브러리 추가

dependencies {
compile 'com.jakewharton:butterknife:7.0.1'}

2) ButterKnife 라이브러리 bind

onCreate메서드에서 setContentView(LayoutID);를 한 후에, 바인드를 해주어야 함

Butternife.bind(this);

3. 기능

1) View를 담을 변수를 선언

이때까지 귀찮게, findViewById(viewID)를 하는 것을 내부적으로 ButterKnife가 도와주게 됨

@Bind(R.id.tv_info) TextView tv_info;
@Bind(R.id.btn_method) Button btn_method;
@Bind(R.id.btn_listener) Button btn_listener;
@Bind(R.id.btn_implements) Button btn_implements;

class ExampleActivity extends Activity {
  @BindView(R.id.title) TextView title;
  @BindView(R.id.subtitle) TextView subtitle;
  @BindView(R.id.footer) TextView footer;

  @Override public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.simple_activity);
    ButterKnife.bind(this);
    // TODO Use fields...
  }
}

2) View Lists

여러 View를 (예제에서는 EditText) List로 관리하는 예제입니다. View들을 List에 담아 놓고 ButterKnife.apply()함수로 속성값을 일괄 적용하는 모습을 보여주고 있는데요 DISABLE, ENABLED와 같은 interface가 어떻게 되어 있는지 구현부 까지 보여주고 있습니다.

// You can group multiple views into a List or array.
@BindViews({ R.id.first_name, R.id.middle_name, R.id.last_name })
List<EditText> nameViews;

// The apply method allows you to act on all the views in a list at once.
ButterKnife.apply(nameViews, DISABLE);
ButterKnife.apply(nameViews, ENABLED, false);

// Action and Setter interfaces allow specifying simple behavior.
static final ButterKnife.Action<View> DISABLE = new ButterKnife.Action<View>() {
@Override
public void apply(View view, int index) {
view.setEnabled(false);
}
};
static final ButterKnife.Setter<View, Boolean> ENABLED = new ButterKnife.Setter<View, Boolean>() {
@Override
public void set(View view, Boolean value, int index) {
view.setEnabled(value);
}
};

// An Android Property can also be used with the apply method.
ButterKnife.apply(nameViews, View.ALPHA, 0.0f);

3) Listener Binding (onClickListener)

@OnClick(R.id.btn_method)
void methodButtonClick() {
}

@OnClick(R.id.btn_listener)
void listenerButtonClick() {
}

@OnClick(R.id.btn_implements)
void implementsButtonClick() {
}

@OnClick({R.id.btn_method, R.id.btn_listener, R.id.btn_implements})
void buttonEvents(View v) {
//이벤트를 처리할 로직...
}

4) Resource Binding

Bind pre-defined resources with @BindBool, @BindColor, @BindDimen, @BindDrawable, @BindInt, @BindString, which binds an R.bool ID (or your specified type) to its corresponding field.

class ExampleActivity extends Activity {
  @BindString(R.string.title) String title;
  @BindDrawable(R.drawable.graphic) Drawable graphic;
  @BindColor(R.color.red) int red; // int or ColorStateList field
  @BindDimen(R.dimen.spacer) Float spacer; // int (for pixel size) or float (for exact value) field
  // ...
}

5) Non-Activity Binding

You can also perform binding on arbitrary objects by supplying your own view root.

public class FancyFragment extends Fragment {
  @BindView(R.id.button1) Button button1;
  @BindView(R.id.button2) Button button2;

  @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fancy_fragment, container, false);
    ButterKnife.bind(this, view);
    // TODO Use fields...
    return view;
  }
}

6) Binding Reset

Fragments have a different view lifecycle than activities. When binding a fragment in onCreateView, set the views to null in onDestroyView. Butter Knife returns an Unbinder instance when you call bind to do this for you. Call its unbind method in the appropriate lifecycle callback

public class FancyFragment extends Fragment {
  @BindView(R.id.button1) Button button1;
  @BindView(R.id.button2) Button button2;
  private Unbinder unbinder;

  @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fancy_fragment, container, false);
    unbinder = ButterKnife.bind(this, view);
    // TODO Use fields...
    return view;
  }

  @Override public void onDestroyView() {
    super.onDestroyView();
    unbinder.unbind();
  }
}

7) Adapter

Another use is simplifying the view holder pattern inside of a list adapter

public class MyAdapter extends BaseAdapter {
  @Override
  public View getView(int position, View view, ViewGroup parent) {
    ViewHolder holder;
    if (view != null) {
      holder = (ViewHolder) view.getTag();
    } else {
      view = inflater.inflate(R.layout.whatever, parent, false);
      holder = new ViewHolder(view);
      view.setTag(holder);
    }

    holder.name.setText("John Doe");
    // etc...

    return view;
  }

  static class ViewHolder {
    @BindView(R.id.title) TextView name;
    @BindView(R.id.job_title) TextView jobTitle;

    public ViewHolder(View view) {
      ButterKnife.bind(this, view);
    }
  }
}

8) Multi-Method Listeners

Method annotations whose corresponding listener has multiple callbacks can be used to bind to any one of them. Each annotation has a default callback that it binds to. Specify an alternate using the callback parameter.

@OnItemSelected(R.id.list_view)
void onItemSelected(int position) {
// TODO ...
}
@OnItemSelected(value = R.id.maybe_missing, callback = NOTHING_SELECTED)
void onNothingSelected() {
// TODO ...
}

9) Optional Bindings

@Nullable
@BindView(R.id.might_not_be_there) TextView mightNotBeThere;
@Optional
@OnClick(R.id.maybe_missing) void onMaybeMissingClicked() {
// TODO ...
}

10) ETC

Also included are findById methods which simplify code that still has to find views on a View, Activity, or Dialog. It uses generics to infer the return type and automatically performs the cast.

View view = LayoutInflater.from(context).inflate(R.layout.thing, null);
TextView firstName = ButterKnife.findById(view, R.id.first_name);
TextView lastName = ButterKnife.findById(view, R.id.last_name);
ImageView photo = ButterKnife.findById(view, R.id.photo);

Add a static import for ButterKnife.findById and enjoy even more fun.

4. License

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

출처 : 인터넷에서 RxAndroid 검색하여 필요한 정보를 다양한 사이트에서 종합하여 작성된 것입니다. 많은 사이트 내용을 종합하여 공부하여 작성하다보니 일일이 나열하지 못하였습니다. ㅈㅅ(_ _) 이글은 자유롭게 퍼 가셔서 도움이 되었으면 좋겠습니다. 감사합니다.

[STUDY] RxAndroid Part 9 (Connectable Observable )

[목차]==================================================

1. Connectable Observable 정의

2. Connectable Observable 사용 예제

======================================================

1. Connectable Observable 정의

Connectable Observable은 구독을 하더라도 이템 방출을 시작하지 않는다는 점을 제외하면 일반적인 Observable과 비슷합니다. connect()을 호출했을 때에만 방출합니다. 이 방법으로 Subscriber들에게 Observable가 방출을 시작하기전에 Observable구독하도록 기다릴 수 있습니다.

ConnectableObservable.connect( ) — Connectable Observable에게 아이템 방출을 시작하라고 지시한다.
Observable.publish( ) — Observable을 Connectable Observable으로 변형시킨다.
Observable.replay( ) — 모든 Observer들에게 방출이 시작된 후에 구독을 했을 경우라도 같은 순서의 방출된 아이템을 볼 수 있도록 보장합니다.
ConnectableObservable.refCount( ) — Connectable Observable을 일반적인 Observable처럼 작동하도록 만듭니다.

2. Connectable Observable 사용 예제

아래의 예제코드는 같은 Observable을 구독하는 두개의 subscriber를 보여주는 코드입니다. 첫번째 케이스에서는 일반적인 Observable이고 두번째 케이스에서는 Connectable Observable으로 subscriber가 모두 구독한 이후 연결하였습니다.

Observable firstMillion = Observable.range( 1, 1000000 ).sample(7, java.util.concurrent.TimeUnit.MILLISECONDS);

firstMillion.subscribe(
   { println("Subscriber #1:" + it); },       // onNext
   { println("Error: " + it.getMessage()); }, // onError
   { println("Sequence #1 complete"); }       // onCompleted
);

firstMillion.subscribe(
    { println("Subscriber #2:" + it); },       // onNext
    { println("Error: " + it.getMessage()); }, // onError
    { println("Sequence #2 complete"); }       // onCompleted
);

Subscriber #1:211128
Subscriber #1:411633
Subscriber #1:629605
Subscriber #1:841903
Sequence #1 complete
Subscriber #2:244776
Subscriber #2:431416
Subscriber #2:621647
Subscriber #2:826996
Sequence #2 complete

Observable firstMillion = Observable.range( 1, 1000000 ).sample(7, java.util.concurrent.TimeUnit.MILLISECONDS).publish();

firstMillion.subscribe(
   { println("Subscriber #1:" + it); },       // onNext
   { println("Error: " + it.getMessage()); }, // onError
   { println("Sequence #1 complete"); }       // onCompleted
);
firstMillion.subscribe(
   { println("Subscriber #2:" + it); },       // onNext
   { println("Error: " + it.getMessage()); }, // onError
   { println("Sequence #2 complete"); }       // onCompleted
);
firstMillion.connect();

Subscriber #2:208683
Subscriber #1:208683
Subscriber #2:432509
Subscriber #1:432509
Subscriber #2:644270
Subscriber #1:644270
Subscriber #2:887885
Subscriber #1:887885
Sequence #2 complete
Sequence #1 complete

[STUDY] RxAndroid Part 8 (Error 핸들링 방법)

[목차]==================================================

1. onError 해주지 않으면 Crash가 발생 주의
2. subscribe 에서 에러 처리
3. Error 캐치 - onErrorReturn
4. Error 캐치 - OnErrorResumeNext
5. Retry
6. Retry 횟수 제한
7. RetryWhen

======================================================

RxJava & RxAndroid 사용 시 항상 에러 핸들러를 구독하고 제공하는지 항상 확인해야 합니다. 그렇지 않으면 특히 Scheduler를 적용할 때 스택 트레이스에 아무것도 없을 수 있습니다. 물론 RxJava & RxAndroid 에서 뭔가 잘못됐다고 알려주긴 하지만 어디서 발생했는지 찾을 방법이 없습니다. 항상 에러 콜백을 사용하고, 에러가 발생한다면 에러를 로그로 남겨서 예상치 못한 오류를 기록해야 합니다.

1. onError 해주지 않으면 Crash가 발생 주의

Observable.create(new ObservableOnSubscribe<String>() {
            @Override
            public void subscribe(ObservableEmitter<String> subscriber) throws Exception {
                log("subscribe");
                subscriber.onNext("emit 1");
                subscriber.onNext("emit 2");
                subscriber.onError(new Throwable());
            }
        }).subscribe(new Consumer<String>() {
            @Override
            public void accept(String s) throws Exception {
                log("on next: " + s);
            }
        });

2. subscribe 에서 에러 처리

Observable.create(new ObservableOnSubscribe<String>() {
            @Override
            public void subscribe(ObservableEmitter<String> subscriber) throws Exception {
                log("subscribe");
                subscriber.onNext("emit 1");
                subscriber.onNext("emit 2");
                subscriber.onError(new Throwable());
            }
        }).subscribe(new DefaultObserver<String>() {
            @Override
            public void onNext(String value) {
                log("on next: " + value);
            }
            @Override
            public void onError(Throwable e) {
                // 에러시 처리를 여기로 받음
                log("error:" + e);
            }
            @Override
            public void onComplete() {
                log("completed");
            }
        });

[출력결과]
subscribe
on next: emit 1
on next: emit 2
error:java.lang.Throwable

3. Error 캐치 - onErrorReturn
Observable 체인 안에서 발생한 Error 를 캐치해서, 대체할 Object로 변환하는 것으로 subscriber에 Error가 전달되는 것을 막을 수 있다.

Observable.create(new ObservableOnSubscribe<String>() {
            @Override
            public void subscribe(ObservableEmitter<String> subscriber) throws Exception {
                log("subscribe");
                subscriber.onNext("emit 1");
                subscriber.onNext("emit 2");
                subscriber.onError(new Throwable());            }
        }).onErrorReturn(new Function<Throwable, String>() {
            @Override
            public String apply(Throwable throwable) throws Exception {
                return "return";
            }
        }).subscribe(new DefaultObserver<String>() {
            @Override
            public void onNext(String value) {
                log("on next: " + value);
            }
            @Override
            public void onError(Throwable e) {
                // 에러시 처리를 여기로 받음
                log("error:" + e);
            }
            @Override
            public void onComplete() {
                log("completed");
            }
        });

[출력결과]
subscribe
on next: emit 1
on next: emit 2
on next: return
completed

4. Error 캐치 - OnErrorResumeNext
Observable 체인에서 발생한 Error를 캐치해서, 그 안에서 다시 한 번 Observable를 호출하면 에러시 대체 Stream을 반환할 수 있다.

Observable.create(new ObservableOnSubscribe<String>() {
            @Override
            public void subscribe(ObservableEmitter<String> subscriber) throws Exception {
                log("subscribe");
                subscriber.onNext("emit 1");
                subscriber.onNext("emit 2");
                subscriber.onError(new Throwable());            }
        }).onErrorResumeNext(new Function<Throwable, ObservableSource<? extends String>>() {            @Override
            public ObservableSource<? extends String> apply(Throwable throwable) throws Exception {
                return Observable.fromArray(new String[]{"resume 1", "resume 2"});
            }
        }).subscribe(new DefaultObserver<String>() {
            @Override
            public void onNext(String value) {
                log("on next: " + value);
            }
            @Override
            public void onError(Throwable e) {
                // 에러시 처리를 여기로 받음
                log("error:" + e);
            }
            @Override
            public void onComplete() {
                log("completed");
            }
        });

[출력결과]
subscribe
on next: emit 1
on next: emit 2
on next: resume 1
on next: resume 2
completed

5. Retry
Error가 일어났을 때, 자동으로 subscribe를 다시 해준다.

성공할때까지 계속... 무한루프 될 가능성이 있으므로 유의해야 한다

Observable.create(subscriber -> {
            log("subscribe");
            subscriber.onNext("emit 1");
            subscriber.onNext("emit 2");
            subscriber.onError(new Throwable());
        })
        .retry()
        .subscribe()

[출력결과]
subscribe
on next: emit 1
on next: emit 2
subscribe
on next: emit 1
on next: emit 2
subscribe
on next: emit 1
on next: emit 2
.
.
.
반복

6. Retry 횟수 제한

[출력결과]
subscribe
on next: emit 1
on next: emit 2
subscribe
on next: emit 1
on next: emit 2
subscribe
on next: emit 1
on next: emit 2
subscribe
on next: emit 1
on next: emit 2
error:java.lang.Throwable

Retry 좀 더 구체적인 설정

Observable.create(subscriber -> {
            log("subscribe");
            subscriber.onNext("emit 1");
            subscriber.onNext("emit 2");
            subscriber.onError(new Throwable());        })
        .retry(new BiPredicate<Integer, Throwable>() {
            @Override
            public boolean test(Integer integer, Throwable throwable) throws Exception {
                if (integer < 3) {
                    return true;
                }
                return throwable instanceof IllegalStateException;
            }
        })
        .subscribe(s -> log("on next: " + s)
            , e -> log("error:" + e)
            , () -> log("completed"));

[출력결과]
subscribe
on next: emit 1
on next: emit 2
subscribe
on next: emit 1
on next: emit 2
subscribe
on next: emit 1
on next: emit 2
error:java.lang.Throwable

7. RetryWhen
보다 세밀하게 retry 처리를 제어하기 위한 함수.

Observable.create(subscriber -> {
            log("subscribe");
            subscriber.onNext("emit 1");
            subscriber.onNext("emit 2");
            subscriber.onError(new Throwable());        }).retryWhen(new Function<Observable<Throwable>, ObservableSource<?>>() {
            @Override
            public ObservableSource<?> apply(Observable<Throwable> throwableObservable) throws Exception {
                return throwableObservable.flatMap(new Function<Throwable, ObservableSource<?>>() {
                    @Override
                    public ObservableSource<?> apply(Throwable throwable) throws Exception {
                        return Observable.timer(3, TimeUnit.SECONDS);
                    }
                });
            }        }).subscribe(s -> log("on next: " + s)
                        , e -> log("error:" + e)
                        , () -> log("completed"));

[출력결과]
subscribe
on next: emit 1
on next: emit 2
// 3초 후
subscribe
on next: emit 1
on next: emit 2
// 3초 후
subscribe
on next: emit 1
on next: emit 2
.
.
.
반복

그냥 Error인채로 종료

Observable.create(subscriber -> {
            log("subscribe");
            subscriber.onNext("emit 1");
            subscriber.onNext("emit 2");
            subscriber.onError(new Throwable());
        }).subscribeOn(AndroidSchedulers.mainThread())
                .retryWhen(throwableObservable -> throwableObservable.flatMap(
                        throwable -> Observable.error(throwable)
                )).subscribe(s -> log("on next: " + s)
                , e -> log("error:" + e)
                , () -> log("completed"));

Error에 대한 처리를 하지 않고 Complete하기

Observable.create(subscriber -> {
            log("subscribe");
            subscriber.onNext("emit 1");
            subscriber.onNext("emit 2");
            subscriber.onError(new Throwable());
        }).onErrorResumeNext(throwable -> {Observable.empty();})                .subscribe(s -> log("on next: " + s)
                , e -> log("error:" + e)
                , () -> log("completed"));

[출력결과]
subscribe
on next: emit 1
on next: emit 2
completed

3번 retry하고 종료
이 경우, 앞의 retry(count) 함수와의 차이는 retry(count)에서는 retry 횟수가 제한에 도달한 후에 error로 종료합니다만, 이 케이스는 completed 에서 종료한다는 점이다.

Observable.create(subscriber -> {
            log("subscribe");
            subscriber.onNext("emit 1");
            subscriber.onNext("emit 2");
            subscriber.onError(new Throwable());        }).retryWhen(throwableObservable -> throwableObservable.take(3))                .subscribe(s -> log("on next: " + s)
                , e -> log("error:" + e)
                , () -> log("completed"));

[출력결과]
subscribe
on next: emit 1
on next: emit 2
subscribe
on next: emit 1
on next: emit 2
subscribe
on next: emit 1
on next: emit 2
completed

3초 retry를 3번 하고 종료하기

Observable.create(subscriber -> {
            log("subscribe");
            subscriber.onNext("emit 1");
            subscriber.onNext("emit 2");
            subscriber.onError(new Throwable());
        }).retryWhen(new Function<Observable<Throwable>, ObservableSource<?>>() {
            @Override
            public ObservableSource<?> apply(@NonNull Observable<Throwable> throwableObservable) throws Exception {
                return throwableObservable.take(3).flatMap(new Function<Throwable, ObservableSource<?>>() {
                    @Override
                    public ObservableSource<?> apply(@NonNull Throwable throwable) throws Exception {
                        return Observable.timer(3, TimeUnit.SECONDS);
                    }
                });
            }
        }).subscribe(s -> log("on next: " + s)
                        , e -> log("error:" + e)
                        , () -> log("completed"));

[출력결과]
subscribe
on next: emit 1
on next: emit 2
// 3초 후
subscribe
on next: emit 1
on next: emit 2
// 3초 후
subscribe
on next: emit 1
on next: emit 2
completed