title: In R, how to plot into a memory buffer instead of a file?
body: <p>I'm using JRI to generate ggplot2 plots from Java.  Currently I have to write plots to disk.  How do I do this without going through files, i.e. just rendering the plots in memory?</p>
  
  <p>I tried using the Cairo package to plot to a textConnection, but that doesn't work without the "R Connections Patch," which after some Googling turns out to be ancient history.</p>