Android studio JavaDoc错误引发NullPointerException

Question

Android studio无法创建JavaDoc。它引发空指针异常，无法识别任何android打包的项目。

...
/home/<user>/AndroidStudioProjects/<project>/app/src/main/java/com/example/simpleparadox/listycity/MainActivity.java:14: error: cannot access ViewGroup
public class MainActivity extends AppCompatActivity {
       ^
  class file for android.view.ViewGroup not found
javadoc: error - fatal error encountered: java.lang.NullPointerException
javadoc: error - Please file a bug against the javadoc tool via the Java bug reporting page
(http://bugreport.java.com) after checking the Bug Database (http://bugs.java.com)
for duplicates. Include error messages and the following diagnostic in your report. Thank you.
java.lang.NullPointerException
    at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$MembersPhase.runPhase(TypeEnter.java:934)
    at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$Phase.doCompleteEnvs(TypeEnter.java:282)
    at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$MembersPhase.doCompleteEnvs(TypeEnter.java:877)
    at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$Phase.completeEnvs(TypeEnter.java:251)
    at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$Phase.completeEnvs(TypeEnter.java:266)
    at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$Phase.completeEnvs(TypeEnter.java:266)
    at jdk.compiler/com.sun.tools.javac.comp.TypeEnter$Phase.completeEnvs(TypeEnter.java:266)
    at jdk.compiler/com.sun.tools.javac.comp.TypeEnter.complete(TypeEnter.java:198)
    at jdk.compiler/com.sun.tools.javac.code.Symbol.complete(Symbol.java:642)
    at jdk.compiler/com.sun.tools.javac.code.Symbol$ClassSymbol.complete(Symbol.java:1326)
    at jdk.compiler/com.sun.tools.javac.comp.Enter.complete(Enter.java:583)
    at jdk.compiler/com.sun.tools.javac.comp.Enter.main(Enter.java:560)
    at jdk.javadoc/jdk.javadoc.internal.tool.JavadocEnter.main(JavadocEnter.java:79)
    at jdk.javadoc/jdk.javadoc.internal.tool.JavadocTool.getEnvironment(JavadocTool.java:206)
    at jdk.javadoc/jdk.javadoc.internal.tool.Start.parseAndExecute(Start.java:576)
    at jdk.javadoc/jdk.javadoc.internal.tool.Start.begin(Start.java:432)
    at jdk.javadoc/jdk.javadoc.internal.tool.Start.begin(Start.java:345)
    at jdk.javadoc/jdk.javadoc.internal.tool.Main.execute(Main.java:63)
    at jdk.javadoc/jdk.javadoc.internal.tool.Main.main(Main.java:52)
7 errors

然后，我在JavaDoc对话框的另一个命令行参数文本框中找到了一个将bootclasspath path\u添加到sdk\u android\u jar\u文件的工作。

但是，较新的Java弃用的-bootclasspath。它会引发另一个错误，如下所示：

error: option --boot-class-path not allowed with target 11

所以我改用了sourcepath。这带来了旧错误（NullPointerException）。

在这一点上我几乎迷路了。

顺便说一下，如果我选择一个只有Java元素（没有android）的类，并且只为该特定文件创建JavaDoc，那么它会很好地创建JavaDoc。但是对于一个有很多类的项目来说，这不是一个好的解决方法。

Answer 1

我面临着与您相同的问题，有几个进口错误...

以下解决方案对我有用（我从mike192的答案中得到的，请参阅此处链接）

task javadoc(type: Javadoc) {

    doFirst {
        configurations.implementation
                .filter { it.name.endsWith('.aar') }
        .each { aar ->
            copy {
                from zipTree(aar)
                include "**/classes.jar"
                into "$buildDir/tmp/aarsToJars/${aar.name.replace('.aar', '')}/"
            }
        }
    }

    configurations.implementation.setCanBeResolved(true)
    source = android.sourceSets.main.java.srcDirs
    classpath += project.files(android.getBootClasspath().join(File.pathSeparator))
    classpath += configurations.implementation
    classpath += fileTree(dir: "$buildDir/tmp/aarsToJars/")
    destinationDir = file("${project.buildDir}/outputs/javadoc/")
    failOnError false
    exclude '**/BuildConfig.java'
    exclude '**/R.java'
}