设置minifyEnabled为true后无法生成带签名的APk

Question

我已经将minifyEnabled设置为true，但之后我无法生成签名的apk。

它显示警告和错误：

Warning:com.fasterxml.jackson.databind.ext.DOMSerializer: can't find referenced class org.w3c.dom.bootstrap.DOMImplementationRegistry
Warning:okio.DeflaterSink: can't find referenced class org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
Warning:okio.Okio: can't find referenced class java.nio.file.Files
Warning:okio.Okio: can't find referenced class java.nio.file.Path
Warning:okio.Okio: can't find referenced class java.nio.file.OpenOption
Warning:okio.Okio: can't find referenced class java.nio.file.Path
Warning:okio.Okio: can't find referenced class java.nio.file.OpenOption
Warning:okio.Okio: can't find referenced class org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
Warning:okio.Okio: can't find referenced class java.nio.file.Path
Warning:okio.Okio: can't find referenced class java.nio.file.OpenOption
Warning:okio.Okio: can't find referenced class java.nio.file.Path
Warning:okio.Okio: can't find referenced class java.nio.file.OpenOption
Warning:okio.Okio: can't find referenced class org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
Warning:retrofit2.Platform$Java8: can't find referenced method 'boolean isDefault()' in library class java.lang.reflect.Method
Warning:retrofit2.Platform$Java8: can't find referenced class java.lang.invoke.MethodHandles$Lookup
Warning:retrofit2.Platform$Java8: can't find referenced class java.lang.invoke.MethodHandle
Warning:retrofit2.Platform$Java8: can't find referenced class java.lang.invoke.MethodHandles
Warning:retrofit2.Platform$Java8: can't find referenced class java.lang.invoke.MethodHandle
Warning:retrofit2.Platform$Java8: can't find referenced class java.lang.invoke.MethodHandles$Lookup
Warning:retrofit2.Platform$Java8: can't find referenced class org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement
Warning:there were 27 unresolved references to classes or interfaces.
Warning:there were 1 unresolved references to library class members.
Warning:Exception while processing task java.io.IOException: Please correct the above warnings first.
Error:Execution failed for task ':app:transformClassesAndResourcesWithProguardForRelease'.
> Job failed, see logs for details

现在，当我将minifyEnabled设置为false时，它将允许我生成签名的apk，但我希望将其设置为true。

我该如何解决这个问题呢？

Answer 1

这是okio和proguard的一个问题。

关注this link可以获得详细的解释，但简而言之，您似乎需要将这些行添加到项目中的proguard-rules文件中。

-dontwarn okhttp3.**
-dontwarn okio.**

Answer 2

在proguard-rules文件中添加以下行：

-dontwarn okhttp3.**
-dontwarn okio.**
-dontwarn com.fasterxml.jackson.databind.**

Reference