问题
Is there a java sdk for cygwin?
回答1:
It would be nice if there were a native cygwin implementation which used the cygwin file system and X-windows for display, unfortunately I am not aware of such a release. I would assume it is quite an effort to port OpenJDK as well, but I haven't tried.
回答2:
Although there is no java sdk for cygwin, you can get the Windows jdk to work if you are willing to accommodate workarounds for various problems:
- some cygwin paths are not handled as expected by java programs
- the file path separator is backslash rather than slash
- the PATH entry separator is semicolon instead of colon
In my experience, the first bullet is by far biggest problem, although the three are somewhat inter-related. The separators tend to take care of themselves as a side-effect of solving the first problem.
All three problems are largely resolved by setting up a development environment in which all file paths of interest (as viewed by java.io.File and java.nio.Path, etc.) can be represented without specifying a drive letter.
As it turns out, it's rarely necessary to use backslashes in a file path string under windows. The only exceptions to this rule that I have encountered are when passing file path strings as parameters when spawning a command line for a program that require backslashes (e.g., CMD.EXE). The java.io and java.nio packages all accept forward slashes, and so, for that matter, do the Microsoft development libraries. Most programs that reject a path with forward slashes are (IMHO) likely to be doing so gratuitously.
So, the real problem is that "/cygdrive/c" is not recognized by java.io.File as referring to "C:\".
In other words, the following file test will return false:
new java.io.File("/cygdrive/c").exists()
whereas this works as expected:
new java.io.File("c:/").exists()
Recent versions of Windows now support general symlinks, providing a way to setup a cygwin development environment in which drive letters are not used. With a unified view of the entire filesystem (with all files appearing below "/", the default drive letter being invariant, e.g., C:) , the drive letter can be discarded from file path strings. In other words, you want to be able to refer to "c:/" as "/". This can be accomplished in various ways, one being to symlink other drives below c:/, for example:
$ ln -sFT d:/ c:/d
If env variable CYGWIN contains "winsymlinks:native", this will create a Windows symlink, with the result that (assuming c: is the default drive) your java program will correctly recognize the string "/d" as referring to "D:\", so you can do this:
new java.io.File("/d").isDirectory // returns true, as expected
If you are unable or reluctant to modify you cygwin environment, there is another approach, which is more universal. You can extend java.io.File and override constructors and various methods to (in effect) to translate cygwin paths to their windows equivalent (like cygpath -m or -w), and to translate windows path strings to a more POSIX-like format. I have such a library (written in scala, but usable from java) and intend to make it available, hopefully sometime soon.
来源：https://stackoverflow.com/questions/1030447/is-there-a-java-sdk-for-cygwin