Error:Execution failed for task ':ReactAndroid:downloadBoost'.

javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

在ReactAndroid工程中找到build.gradle

找到下面的代码

  task downloadBoost(dependsOn: createNativeDepsDirectories, type: Download) {  // Use ZIP version as 
  it's faster this way to selectively extract some parts of the archive  src 
  '[https://downloads.sourceforge.net/project/boost/boost/1.57.0/boost_1_57_0.zip]
  (https://downloads.sourceforge.net/project/boost/boost/1.57.0/boost_1_57_0.zip)'  // alternative // src 
  '[http://mirror.nienbo.com/boost/boost_1_57_0.zip](http://mirror.nienbo.com/boost/boost_1_57_0.zip)'  
  onlyIfNewer true  overwrite false  dest new File(downloadsDir, 'boost_1_57_0.zip') }

由于下载boost_1_57_0.zip问题导致的上面的错误

解决办法：

1、根据上面代码中的下载链接，自行下载文件

2、将boost_1_57_0.zip 放到../node_modules/react-native/ReactAndroid/build/downloads/目录下即可fix