我一直认为这Predef.println只是一个捷径System.out.println,但显然我错了,因为它似乎根本没用System.out.为什么会这样？我怎样才能System.out在Scala中进行下面的"重定向" ？
scala> val baos = new java.io.ByteArrayOutputStream
baos: java.io.ByteArrayOutputStream =
scala> val ps = new java.io.PrintStream(baos)
ps: java.io.PrintStream = java.io.PrintStream@6c5ac4
scala> System.setOut(ps)
scala> println("hello")
hello
scala> new String(baos.toByteArray)
res2: java.lang.String = ""
scala> System.out.println("hello")
scala> new String(baos.toByteArray)
res7: java.lang.String =
"hello
"