我正在尝试使用新的Android Studio,但我似乎不能让它正常工作。
我正在使用Gson库来序列化/反序列化json对象。但是这个库不知何故没有包含在构建中。
我用MainActivity创建了一个新项目。
复制gson-2.2.3.jar到/libs文件夹中,并将其添加为库依赖项(右键单击->添加为库)。这包括android studio中的jar,因此可以从源文件中引用它。
当我尝试运行项目时,它无法编译,所以我添加:
compile files('libs/gson-2.2.3.jar')
到de .gradle文件中的依赖项。之后,它正确编译,但当运行应用程序时,我得到一个ClassDefNotFoundException。
有人知道我哪里做错了吗?
我已经为同样的事情挣扎了好几个小时,试图让Gson罐子工作。我终于破解了——下面是我采取的步骤:
Put the Gson jar (in my case, gson-2.2.4.jar) into the libs folder
Right click it and hit 'Add as library'
Ensure that compile files('libs/gson-2.2.4.jar') is in your build.gradle file (or compile fileTree(dir: 'libs', include: '*.jar') if you are using many jar files)
Edit : Use implementation files('libs/gson-2.2.4.jar') (or implementation fileTree(dir: 'libs', include: '*.jar')) in Android Studio 3.0+
Do a clean build (you can probably do this fine in Android Studio, but to make sure I navigated in a terminal to the root folder of my app and typed gradlew clean. I'm on Mac OS X, the command might be different on your system
在我完成以上四项之后,它开始正常工作。我认为“添加为库”步骤是我之前错过的一个步骤,直到我清理它它才开始工作。
[编辑-添加构建Gradle步骤也是必要的,正如其他人指出的那样]
在Kotlin DSL (build.gradle.kts)中,有多种方法可以做到这一点。
我们假设库文件在project/app/libs/目录下。
Method 1
implementation(
files(
"libs/library-1.jar",
"libs/library-2.jar",
"$rootDir/foo/my-common-library.jar"
)
)
Method 2
implementation(
fileTree("libs/") {
// You can add as many include or exclude calls as you want
include("*.jar")
include("another-library.aar") // aar is similar to jar
exclude("bad-library.jar")
}
)
Method 3
implementation(
fileTree(
// Here, instead of repeating include or exclude, assign a list
"dir" to "libs/",
"include" to "*.jar",
"exclude" to listOf("bad-library-1.jar", "bad-library-2.jar")
)
)
Method 4
repositories {
flatDir {
dirs("libs/", "lib/")
}
}
dependencies {
// Could also write implementation(":jsoup:1.4.13")
implementation("org.jsoup:jsoup:1.4.13")
// NOTE: Add @aar suffix for AAR files
implementation("ir.mahozad.android:pie-chart:0.7.0@aar")
}
您可以在包含和排除调用中使用Ant模式,如上所示。
有关这方面的更多信息,请参阅Gradle文档。
感谢这篇文章和这篇文章提供了有用的答案。