已经下载安装了Java和jdk7
问题如下：
> install.packages("Rwordseg", repos="http://R-Forge.R-project.org")
Warning in install.packages :
  unable to access index for repository http://R-Forge.R-project.org/bin/macosx/el-capitan/contrib/3.5:
  无法打开URL'http://R-Forge.R-project.org/bin/macosx/el-capitan/contrib/3.5/PACKAGES'
installing the source package ‘Rwordseg’

试开URL’http://R-Forge.R-project.org/src/contrib/Rwordseg_0.2-1.tar.gz'
Content type 'application/x-gzip' length 5445754 bytes (5.2 MB)
==================================================
downloaded 5.2 MB

* installing *source* package ‘Rwordseg’ ...
** R
** demo
** inst
** byte-compile and prepare package for lazy loading
Error: package or namespace load failed for ‘rJava’:
.onLoad failed in loadNamespace() for 'rJava', details:
  call: dyn.load(file, DLLpath = DLLpath, ...)
  error: 无法载入共享目标对象‘/Library/Frameworks/R.framework/Versions/3.5/Resources/library/rJava/libs/rJava.so’：:
  dlopen(/Library/Frameworks/R.framework/Versions/3.5/Resources/library/rJava/libs/rJava.so, 6): Library not loaded: /Library/Java/JavaVirtualMachines/jdk-11.0.1.jdk/Contents/Home/lib/server/libjvm.dylib
  Referenced from: /Library/Frameworks/R.framework/Versions/3.5/Resources/library/rJava/libs/rJava.so
  Reason: image not found
Error : package ‘rJava’ could not be loaded
ERROR: lazy loading failed for package ‘Rwordseg’
* removing ‘/Library/Frameworks/R.framework/Versions/3.5/Resources/library/Rwordseg’
Warning in install.packages :
  installation of package ‘Rwordseg’ had non-zero exit status

The downloaded source packages are in