java.util.zip.ZipException: duplicate entry: org/apache/xmlbeans/xml/stream/Location.class

先说下问题的缘由吧，我是想在自己软件中预览word等文档，网上找了很多种方法，发现其他的虽然都可以实现，也挺好的，但要不就是很麻烦，就是要付费。最后我是打算采用poi，虽然缺点是体验不太好，但没办法，为了是实现功能，我还是都是那采用它。但遇到的下面这个问题，把我搞得有点头疼，国内关于这个的解决办法，很少，找了半天，都是在*上看到有人回答，但是我试了很多，依旧不能解决我的问题。

:ols:incrementalDebugJavaCompilationSafeguard UP-TO-DATE
:ols:compileDebugJavaWithJavac UP-TO-DATE
:ols:compileDebugNdk UP-TO-DATE
:ols:compileDebugSources UP-TO-DATE
:ols:prePackageMarkerForDebug
:ols:transformClassesWithJarMergingForDebug FAILED
Error:Execution failed for task ':ols:transformClassesWithJarMergingForDebug'.
> com.android.build.api.transform.TransformException: java.util.zip.ZipException: duplicate entry: org/apache/xmlbeans/xml/stream/Location.class

这个错误找了好久。把问题记录下吧
在网上找了各种，反正最近的解决办法也是莫名其妙。
*上的解释也是各种，有说是gradle的*库下载的jar包有问题，后来我就到官网下载，地址是：http://poi.apache.org/download.html
我下载的是：poi-bin-3.16-20170419.zip，这个版本，下载完之后，把里面涉及的jar包都导入进去，发现问题依旧，后来我干脆就把其他的jar全删掉，只留下poi-3.16;poi-ooxml-schemas-3.16;poi-scratchpad-3.16这三个包。运行后发现，嘿，居然神奇的这个错误不报了，但同时出现了另外一个问题。

ProGuard, version 5.2.1
Reading program jar [E:\DoubleWork\NEWAPP\ols\build\intermediates\transforms\jarMerging\debug\jars\1\1f\combined.jar]
Reading library jar [D:\LocalSDK\AndroidStudio\sdk\build-tools\24.0.2\lib\shrinkedAndroid.jar]
Preparing output jar [E:\DoubleWork\NEWAPP\ols\build\intermediates\multi-dex\debug\componentClasses.jar]
  Copying resources from program jar [E:\DoubleWork\NEWAPP\ols\build\intermediates\transforms\jarMerging\debug\jars\1\1f\combined.jar]
:ols:transformClassesWithDexForDebug
To run dex in process, the Gradle daemon needs a larger heap.
It currently has approximately 910 MB.
For faster builds, increase the maximum heap size for the Gradle daemon to more than 2048 MB.
To do this set org.gradle.jvmargs=-Xmx2048M in the project gradle.properties.
For more information see https://docs.gradle.org/current/userguide/build_environment.html
Error:UNEXPECTED TOP-LEVEL ERROR:
Error:java.lang.OutOfMemoryError: GC overhead limit exceeded
:ols:transformClassesWithDexForDebug FAILED
Error:Execution failed for task ':ols:transformClassesWithDexForDebug'.
> com.android.build.api.transform.TransformException: com.android.ide.common.process.ProcessException: java.util.concurrent.ExecutionException: com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process 'command 'C:\Program Files\Java\jdk1.8.0_101\bin\java.exe'' finished with non-zero exit value 3

这个问题的关键一句在这

Error:java.lang.OutOfMemoryError: GC overhead limit exceeded

意思很明显，就是内存不足。加内存呗，在Androidstudio的gradle中配置

android {
...
     dexOptions {
        preDexLibraries false
        incremental false
        javaMaxHeapSize "3072m"
     }
...
}

最后运行，问题解决。
这个问题搞得真有点莫名其妙