Your Android Open Source Library

Open source libraries make the development much easier. You don't have to spend your time for making similar things. If you cannot find what you want, now it's time to make it and release to everyone.

In this talk, I explain how to make an open source library including hosting, testing, continuous integration, and publishing for both types: jar(java) and aar(android)

Transcript

1. Your Android 
 Open Source Library Think, Build, Ship and Tweak Sangsoo Nam sangsoo@spotify.com
2. Sangsoo Nam Senior Android Engineer at Spotify sangsoonam.github.io @sangsoonam
3. Open Source
4. Open Source Show your work
5. Open Source Show your work Teach others
6. Open Source Show your work Teach others Lower bugs
7. Open Source Show your work Teach others Lower bugs Upstream improvement
8. Open Source Show your work Teach others Lower bugs Great advertising Upstream improvement
9. Open Source Show your work Teach others Lower bugs It’s fun! Great advertising Upstream improvement
10. https:/ /spotify.github.io/
11. https:/ /spotify.github.io/
12. https:/ /spotify.github.io/
14. Open Source Library
15. Open Source Library Dagger2
16. Open Source Library Dagger2 Picasso
17. Open Source Library Dagger2 Picasso RxJava
18. Open Source Library Dagger2 Picasso RxJava OkHttp
19. Open Source Library Dagger2 Picasso RxJava OkHttp Guava
20. Open Source Library Dagger2 Picasso RxJava AutoValue OkHttp Guava
21. Open Source Library Dagger2 Picasso RxJava AutoValue OkHttp Guava compile ‘xxx:xxx:0.1.0’
22. Java Library
23. Think Build Ship
25. { "items": [ ... { "uri": "spotify:track:7MHN1aCFtLXjownGhvEQlF", "attributes": { "format_attributes": [ { "key": "status", "value": "UP" }, ... ] } }, { "uri": "spotify:track:7nKBxz47S9SD79N086fuhn", "attributes": { "format_attributes": [ { "key": "status", "value": "DOWN" }, ... ] } }, { "uri": "spotify:track:3rOSwuTsUlJp0Pu0MkN8r8", "attributes": { "format_attributes": [ { "key": "status", "value": "EQUAL" }, ... ] ≈ ≈ ≈
26. if ("UP".equals(status)) { showIcon(iconUp); } else if("DOWN".equals(status)) { showIcon(iconDown); } else if("EQUAL".equals(status)) { showIcon(iconEqual); }
27. if ("UP".equals(status)) { showIcon(iconUp); } else if("DOWN".equals(status)) { showIcon(iconDown); } else if("EQUAL".equals(status)) { showIcon(iconEqual); } • Every time string comparison with “equals” method • Typo error (e.g Upper or lower case)
28. if (Status.UP == status) { showIcon(iconUp); } else if(Status.DOWN == status) { showIcon(iconDown); } else if(Status.EQUAL == status) { showIcon(iconEqual); } • No need to compare strings
29. Think Avoid comparing strings every time 
 for JSON data Build Ship
30. Ignore Case "UP" "DOWN" "EQUAL" Status.UP Status.DOWN Status.EQUAL "Up" "up" "DoWn" "down" “equaL"
31. Edge Cases "ALIEN" return null throw new EnumConstantNotPresentException()
32. Edge Cases "ALIEN" return null throw new EnumConstantNotPresentException() "SHUFFLE-PLAY" Mode.SHUFFLE_PLAY • Enum doesn’t allow “_” • Support conversion
43. EnumParser public enum Status { UP, DOWN, EQUAL; } @Test public void testEnumParser() { assertThat(EnumParser.forClass(Status.class).parse("UP")).isSameAs(Status.UP); assertThat(EnumParser.forClass(Status.class).parse("up")).isSameAs(Status.UP); assertThat(EnumParser.forClass(Status.class).parse("uP")).isSameAs(Status.UP); assertThat(EnumParser.forClass(Status.class).parse("DOWN")).isSameAs(Status.DOWN); assertThat(EnumParser.forClass(Status.class).parse("EQUAL")).isSameAs(Status.EQUAL); }
44. EnumParser @Test public void testEnumParser() { assertThat(EnumParser.forClass(Status.class).parse("ALIEN")).isNull(); } @Test(expected = EnumConstantNotPresentException.class) public void testEnumParserStrict() { EnumParser.forClass(Status.class).parseStrict("ALIEN") } @Test public void testEnumParserVariation() { EnumParser<Mode> enumParser = EnumParser.forClass(Mode.class).withVariation( (mode) -> mode.name().replaceAll("_", "-") ); assertThat(enumParser.parse("SHUFFLE_PLAY")).isSameAs(Mode.SHUFFLE_PLAY); assertThat(enumParser.parse("SHUFFLE-PLAY")).isSameAs(Mode.SHUFFLE_PLAY); }
45. EnumParser @Test public void testEnumParser() { assertThat(EnumParser.forClass(Status.class).parse("ALIEN")).isNull(); } @Test(expected = EnumConstantNotPresentException.class) public void testEnumParserStrict() { EnumParser.forClass(Status.class).parseStrict("ALIEN") } @Test public void testEnumParserVariation() { EnumParser<Mode> enumParser = EnumParser.forClass(Mode.class).withVariation( (mode) -> mode.name().replaceAll("_", "-") ); assertThat(enumParser.parse("SHUFFLE_PLAY")).isSameAs(Mode.SHUFFLE_PLAY); assertThat(enumParser.parse("SHUFFLE-PLAY")).isSameAs(Mode.SHUFFLE_PLAY); }
46. Think Avoid comparing strings every time 
 for JSON data Build EnumParser: 
 Case insensitive parser 
 from string to Enum Ship
47. Open Source Library
48. Open Source Library
54. “Is this open source project?”
55. Licenses Exclusive copyright by default. Have to say what others can do with it.
56. MIT Apache 2.0 GPLv3 Permissions • Commercial use • Distribution • Modification • Private use • Commercial use • Distribution • Modification • Private use • Patent use • Commercial use • Distribution • Modification • Private use • Patent use Conditions • License and copyright notice • License and copyright notice • State changes • License and copyright notice • State changes • Disclose source • Same license Limitations • Liability • Warranty • Liability • Warranty • Trademark use • Liability • Warranty Weaker Stronger https:/ /choosealicense.com/licenses/
61. Document What is this project? How to use it? Is it open source? Which license? How can I contribute?
62. https:/ /www.udacity.com/course/writing-readmes--ud777
65. CI Badges Make sure every thing works after any change. Show your project is stable and well tested.
66. Build Status
70. .travis.yml language: java
75. Test Coverage
76. https:/ /coveralls.io/
78. build.gradle plugins { id 'jacoco' id 'com.github.kt3k.coveralls' version '2.8.1' } … jacocoTestReport { reports { xml.enabled = true // coveralls plugin depends on xml format report html.enabled = true } }
79. .travis.yml language: java after_success: - ./gradlew test jacocoTestReport coveralls
84. Open Source Library
85. Open Source Library
86. compile 'com.google.dagger:dagger:2.11' compile 'com.squareup.picasso:picasso:2.5.2' compile 'com.squareup.okhttp3:okhttp:3.8.1'
87. Library Repository Icons made by Freepik from www.flaticon.com is licensed by CC 3.0 BY
88. Library Repository compile ’xxx:xxx:0.1.0’ Icons made by Freepik from www.flaticon.com is licensed by CC 3.0 BY
89. Library Repository compile ’xxx:xxx:0.1.0’ Icons made by Freepik from www.flaticon.com is licensed by CC 3.0 BY
90. Library Repository compile ’xxx:xxx:0.1.0’ JFrog Bintray 
 jcenter Icons made by Freepik from www.flaticon.com is licensed by CC 3.0 BY
91. Library Repository compile ’xxx:xxx:0.1.0’ Sonatype
 Maven Central JFrog Bintray 
 jcenter Icons made by Freepik from www.flaticon.com is licensed by CC 3.0 BY
92. Library Repository compile ’xxx:xxx:0.1.0’ Sonatype
 Maven Central JFrog Bintray 
 jcenter Icons made by Freepik from www.flaticon.com is licensed by CC 3.0 BY
93. jcenter Maven repository hosted by JFrog Bintray. Deliver library though CDN. Largest Java Repository. Support easy way to upload
 Maven Central
94. https:/ /bintray.com
99. Maven A project management and comprehension tool providing a way to help with managing: • Builds • Dependencies • Releases • Distributions
 group_id:artifact_id:version POM(Project Object Model) file describes the project. 'com.google.dagger:dagger:2.11'
100. build.gralde apply plugin: 'maven-publish' ... ext { PUBLISH_GROUP_ID = 'io.github.sangsoonam' PUBLISH_VERSION = '0.1.0' } 
 publishing { publications { MyPublication(MavenPublication) { from components.java groupId = PUBLISH_GROUP_ID version = PUBLISH_VERSION } } }
101. Command ~/enumparser> ./gradlew publishToMavenLocal :enumparser:generatePomFileForMyPublicationPublication :enumparser:compileJava UP-TO-DATE :enumparser:processResources UP-TO-DATE :enumparser:classes UP-TO-DATE :enumparser:jar :enumparser:publishMyPublicationPublicationToMavenLocal :enumparser:publishToMavenLocal BUILD SUCCESSFUL Total time: 5.307 secs ~/enumparser> ls -al ~/.m2/repository/io/github/sangsoonam/enumparser/0.1.0 total 16 drwxr-xr-x 4 sangsoo staff 136 Aug 8 21:36 . drwxr-xr-x 5 sangsoo staff 170 Aug 8 21:36 .. -rw-r--r-- 1 sangsoo staff 2174 Aug 8 21:37 enumparser-0.1.0.jar -rw-r--r-- 1 sangsoo staff 613 Aug 8 21:37 enumparser-0.1.0.pom
102. pom.xml ~/enumparser> cat ~/.m2/repository/io/github/sangsoonam/enumparser/0.1.0/enumparser-0.1.0.pom <?xml version="1.0" encoding="UTF-8"?> <project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/ maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <modelVersion>4.0.0</modelVersion> <groupId>io.github.sangsoonam</groupId> <artifactId>enumparser</artifactId> <version>0.1.0</version> <dependencies> <dependency> <groupId>com.google.guava</groupId> <artifactId>guava</artifactId> <version>11.0.1</version> <scope>runtime</scope> </dependency> </dependencies> </project>
105. Don’t release it manually!
106. build.gralde plugins { id "com.jfrog.bintray" version "1.7" } ... bintray { user = System.getenv('BINTRAY_USER') key = System.getenv('BINTRAY_API_KEY') publications = ['MyPublication'] publish = true pkg { repo = PUBLISH_ARTIFACT_ID name = PUBLISH_ARTIFACT_ID version { name = 'v' + PUBLISH_VERSION released = new Date() } } }
107. Command ~/enumparser> ./gradlew bintrayUpload :enumparser:generatePomFileForMyPublicationPublication :enumparser:compileJava UP-TO-DATE :enumparser:processResources UP-TO-DATE :enumparser:classes UP-TO-DATE :enumparser:jar UP-TO-DATE :enumparser:javadoc UP-TO-DATE :enumparser:javadocJar UP-TO-DATE :enumparser:sourceJar UP-TO-DATE :enumparser:publishMyPublicationPublicationToMavenLocal :enumparser:bintrayUpload BUILD SUCCESSFUL Total time: 6.62 secs
111. build.gralde repositories { maven { url "http://dl.bintray.com/sangsoonam/enumparser" }
 jcenter() } dependencies { compile 'io.github.sangsoonam:enumparser:0.1.0' }
112. Artifact Repository
113. Artifact Repository Maven Release .jar + pom.xml JFrog Bintray 
 jcenter
114. Artifact Repository Maven Release .jar + pom.xml JFrog Bintray 
 jcenter Your Bintray Upload
115. Artifact Repository Maven Release .jar + pom.xml JFrog Bintray 
 jcenter Your Bintray Upload Sync
120. !
121. Maven Central Maven repository hosted by Sonatype. Well known. Quite hard to start but 
 have good guidelines for releasing.
122. https:/ /issues.sonatype.org/
123. https:/ /issues.sonatype.org/
124. https:/ /issues.sonatype.org/
126. Artifact Repository Maven Release .jar + pom.xml JFrog Bintray 
 jcenter Your Bintray Upload Sync
127. Artifact Repository Maven Release .jar + pom.xml JFrog Bintray 
 jcenter Your Bintray Upload Sync Sonatype
 Maven Central Sync
130. Maven Central Requirements Have source and javadoc artifacts. POM(Project Object Model) should have enough information for the project. • Project Name • Project Description • Project URL • License • SCM URL • Developer information Artifacts should be signed for validation.
131. pom.xml ~/enumparser> cat ~/.m2/repository/io/github/sangsoonam/enumparser/0.1.0/enumparser-0.1.0.pom <?xml version="1.0" encoding="UTF-8"?> <project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/ maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <modelVersion>4.0.0</modelVersion> <groupId>io.github.sangsoonam</groupId> <artifactId>enumparser</artifactId> <version>0.1.0</version> <dependencies> <dependency> <groupId>com.google.guava</groupId> <artifactId>guava</artifactId> <version>11.0.1</version> <scope>runtime</scope> </dependency> </dependencies> </project>
132. build.gradle task javadocJar (type: Jar, dependsOn: javadoc) { classifier "sources" from javadoc.destinationDir } task sourceJar(type: Jar) { classifier "javadoc" from sourceSets.main.allJava } publishing { publications { MyPublication(MavenPublication) { from components.java groupId = PUBLISH_GROUP_ID version = PUBLISH_VERSION artifact sourceJar artifact javadocJar } } }
133. build.gradle task javadocJar (type: Jar, dependsOn: javadoc) { classifier "sources" from javadoc.destinationDir } task sourceJar(type: Jar) { classifier "javadoc" from sourceSets.main.allJava } publishing { publications { MyPublication(MavenPublication) { from components.java groupId = PUBLISH_GROUP_ID version = PUBLISH_VERSION artifact sourceJar artifact javadocJar } } } ≈
134. build.gradle publishing { publications { MyPublication(MavenPublication) { from components.java groupId = PUBLISH_GROUP_ID version = PUBLISH_VERSION artifact sourceJar artifact javadocJar pom.withXml { asNode().children().last() + pomConfig } } } }
135. build.gradle publishing { publications { MyPublication(MavenPublication) { from components.java groupId = PUBLISH_GROUP_ID version = PUBLISH_VERSION artifact sourceJar artifact javadocJar pom.withXml { asNode().children().last() + pomConfig } } } } ≈
136. build.gradle publishing { publications { MyPublication(MavenPublication) { from components.java groupId = PUBLISH_GROUP_ID version = PUBLISH_VERSION artifact sourceJar artifact javadocJar pom.withXml { asNode().children().last() + pomConfig } } } } ≈ def pomConfig = { description(PUBLISH_DESCRIPTION){} name PUBLISH_ARTIFACT_ID url GITHUB_URL licenses { license { name 'MIT License' url ‘http://www.opensource.org/...' } } scm { url GITHUB_URL } developers { developer { name DEVELOPER_NAME } } }
137. pom.xml ~/enumparser> cat ~/.m2/repository/io/github/sangsoonam/enumparser/0.1.0/enumparser-0.1.0.pom <?xml version="1.0" encoding="UTF-8"?> ... <description>Utility for parsing a string to Enum constant.</description> <name>enumparser</name> <url>https://github.com/SangsooNam/enumparser</url> <licenses> <license> <name>MIT License</name> <url>http://www.opensource.org/licenses/mit-license.php</url> </license> </licenses> <scm> <url>https://github.com/SangsooNam/enumparser</url> </scm> <developers> <developer> <name>Sangsoo Nam</name> </developer> </developers> </project>
141. Don’t release it manually!
142. Don’t release it manually!
143. build.gralde plugins { id "com.jfrog.bintray" version "1.7" } bintray { user = System.getenv('BINTRAY_USER') key = System.getenv('BINTRAY_API_KEY') publications = ['MyPublication'] publish = true pkg { repo = PUBLISH_ARTIFACT_ID name = PUBLISH_ARTIFACT_ID version { name = 'v' + PUBLISH_VERSION released = new Date() mavenCentralSync { user = System.getenv('OSS_USER') password = System.getenv('OSS_PASSWORD') } } } }
144. build.gralde plugins { id "com.jfrog.bintray" version "1.7" } bintray { user = System.getenv('BINTRAY_USER') key = System.getenv('BINTRAY_API_KEY') publications = ['MyPublication'] publish = true pkg { repo = PUBLISH_ARTIFACT_ID name = PUBLISH_ARTIFACT_ID version { name = 'v' + PUBLISH_VERSION released = new Date() mavenCentralSync { user = System.getenv('OSS_USER') password = System.getenv('OSS_PASSWORD') } } } } ≈
145. Command ~/enumparser> ./gradlew bintrayUpload :enumparser:generatePomFileForMyPublicationPublication :enumparser:compileJava UP-TO-DATE :enumparser:processResources UP-TO-DATE :enumparser:classes UP-TO-DATE :enumparser:jar UP-TO-DATE :enumparser:javadoc UP-TO-DATE :enumparser:javadocJar UP-TO-DATE :enumparser:sourceJar UP-TO-DATE :enumparser:publishMyPublicationPublicationToMavenLocal :enumparser:bintrayUpload BUILD SUCCESSFUL Total time: 6.62 secs
147. “jcenter should be enough to release, but good to follow 
 Maven Central requirements”
148. Android Library
149. AAR Android Archive Library. Includes resources such as layouts, drawables, strings and etc.

150. Think Build Ship
151. Duotone Image A half-tone illustration made from a single original image with two different colours.
152. Duotone Image A half-tone illustration made from a single original image with two different colours.
153. Build Ship Think Convert images as a duotone
165. Sample Code
174. Build DuotoneImageView:
 Custom ImageView for Android Ship Think Convert images as a duotone
178. CI Badges Make sure every thing works after any change. Show your project is stable and well tested.
179. Build Status
181. .travis.yml language: android jdk: oraclejdk8 android: components: - tools - platform-tools - build-tools-25.0.1 - android-25 - extra-android-m2repository
184. Test Coverage
186. build.gradle buildscript { dependencies { classpath 'com.dicedmelon.gradle:jacoco-android:0.1.1' } } plugins { id 'jacoco-android' id 'com.github.kt3k.coveralls' version '2.5.0-x' } android { ... testOptions { unitTests.all { jacoco { // To include Robolectric tests includeNoLocationClasses = true } } } } coveralls { jacocoReportPath = "${buildDir}/reports/jacoco/jacocoTestDebugUnitTestReport/jacocoTestDebugUnitTestReport.xml" }
187. .travis.yml language: android ... after_success: - ./gradlew testDebugUnitTest jacocoTestReport coveralls
190. Artifact Repository compile ’xxx:xxx:0.1.0’ Sonatype
 Maven Central JFrog Bintray 
 jcenter Icons made by Freepik from www.flaticon.com is licensed by CC 3.0 BY
191. Artifact Repository compile ’xxx:xxx:0.1.0’ Sonatype
 Maven Central JFrog Bintray 
 jcenter Icons made by Freepik from www.flaticon.com is licensed by CC 3.0 BY
193. build.gralde apply plugin: 'maven-publish' ext { PUBLISH_GROUP_ID = 'io.github.sangsoonam' PUBLISH_VERSION = '0.1.1' } publishing { publications { MyPublication(MavenPublication) { groupId = PUBLISH_GROUP_ID version = PUBLISH_VERSION artifact "${project.buildDir}/outputs/aar/${project.name}-release.aar" } } } ≈
194. Command ~/duotoneimageview> ./gradlew publishToMavenLocal :duotoneimageview:generatePomFileForMyPublicationPublication :duotoneimageview:javadoc :duotoneimageview:javadocJar :duotoneimageview:sourceJar :duotoneimageview:publishMyPublicationPublicationToMavenLocal :duotoneimageview:publishToMavenLocal BUILD SUCCESSFUL Total time: 7.791 secs ~/duotoneimageview> ls -al ~/.m2/repository/io/github/sangsoonam/duotoneimageview/0.1.0 total 96 drwxr-xr-x 6 sangsoo staff 204 Aug 9 09:51 . drwxr-xr-x 4 sangsoo staff 136 Aug 9 09:51 .. -rw-r--r-- 1 sangsoo staff 16749 Aug 9 08:43 duotoneimageview-0.1.0.aar -rw-r--r-- 1 sangsoo staff 925 Aug 9 09:51 duotoneimageview-0.1.0.pom
197. build.gralde plugins { id "com.jfrog.bintray" version "1.7" } ... bintray { user = System.getenv('BINTRAY_USER') key = System.getenv('BINTRAY_API_KEY') publications = ['MyPublication'] publish = true pkg { repo = PUBLISH_ARTIFACT_ID name = PUBLISH_ARTIFACT_ID version { name = PUBLISH_VERSION released = new Date() } } }
198. Command ~/duotoneimageview> ./gradlew bintrayUpload :duotoneimageview:generatePomFileForMyPublicationPublication :duotoneimageview:javadoc UP-TO-DATE :duotoneimageview:javadocJar UP-TO-DATE :duotoneimageview:sourceJar UP-TO-DATE :duotoneimageview:publishMyPublicationPublicationToMavenLocal :duotoneimageview:bintrayUpload BUILD SUCCESSFUL Total time: 9.842 secs
201. Maven Central Requirements Have source and javadoc artifacts. POM(Project Object Model) should have enough information for the project. • Project Name • Project Description • Project URL • License • SCM URL • Developer information Artifacts should be signed for validation.
202. build.gradle task sourceJar(type: Jar) { classifier = 'sources' from android.sourceSets.main.java.srcDirs } task javadoc(type: Javadoc) { source = android.sourceSets.main.java.srcDirs classpath += project.files(android.getBootClasspath().join(File.pathSeparator)) } task javadocJar(type: Jar, dependsOn: javadoc) { classifier = 'javadoc' from javadoc.destinationDir } publishing { publications { MyPublication(MavenPublication) { groupId = PUBLISH_GROUP_ID version = PUBLISH_VERSION artifact "${project.buildDir}/outputs/aar/${project.name}-release.aar" artifact sourceJar artifact javadocJar } } }
203. build.gradle task sourceJar(type: Jar) { classifier = 'sources' from android.sourceSets.main.java.srcDirs } task javadoc(type: Javadoc) { source = android.sourceSets.main.java.srcDirs classpath += project.files(android.getBootClasspath().join(File.pathSeparator)) } task javadocJar(type: Jar, dependsOn: javadoc) { classifier = 'javadoc' from javadoc.destinationDir } publishing { publications { MyPublication(MavenPublication) { groupId = PUBLISH_GROUP_ID version = PUBLISH_VERSION artifact "${project.buildDir}/outputs/aar/${project.name}-release.aar" artifact sourceJar artifact javadocJar } } } ≈
204. build.gradle publishing { publications { MyPublication(MavenPublication) { groupId = PUBLISH_GROUP_ID version = PUBLISH_VERSION ... artifact sourceJar artifact javadocJar pom.withXml { asNode().children().last() + pomConfig } } } } ≈ def pomConfig = { description(PUBLISH_DESCRIPTION){} name PUBLISH_ARTIFACT_ID url GITHUB_URL licenses { license { name 'MIT License' url ‘http://www.opensource.org/...' } } scm { url GITHUB_URL } developers { developer { name DEVELOPER_NAME } } }
206. build.gralde plugins { id "com.jfrog.bintray" version "1.7" } bintray { user = System.getenv('BINTRAY_USER') key = System.getenv('BINTRAY_API_KEY') publications = ['MyPublication'] publish = true pkg { repo = PUBLISH_ARTIFACT_ID name = PUBLISH_ARTIFACT_ID version { name = PUBLISH_VERSION released = new Date() mavenCentralSync { user = System.getenv('OSS_USER') password = System.getenv('OSS_PASSWORD') } } } } ≈
207. Command ~/duotoneimageview> ./gradlew bintrayUpload :duotoneimageview:generatePomFileForMyPublicationPublication :duotoneimageview:javadoc UP-TO-DATE :duotoneimageview:javadocJar UP-TO-DATE :duotoneimageview:sourceJar UP-TO-DATE :duotoneimageview:publishMyPublicationPublicationToMavenLocal :duotoneimageview:bintrayUpload BUILD SUCCESSFUL Total time: 9.842 secs
210. Summary • Your code is valuable for other developers. Open your code. • Don’t forget the license • Document, document and document. • Continuous Integration: building and unit testing. • Release your library: jcenter or Maven central • Tweak if you have requests or pull request. Lib App Lib Lib
211. Open source repositories • https://github.com/SangsooNam/enumparser • https://github.com/SangsooNam/duotoneimageview Questions Sangsoo Nam sangsoo@spotify.com