Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
        at java.util.Arrays.copyOf(Unknown Source)
        at java.io.ByteArrayOutputStream.grow(Unknown Source)
        at java.io.ByteArrayOutputStream.ensureCapacity(Unknown Source)
        at java.io.ByteArrayOutputStream.write(Unknown Source)
        at ByteArrayStreamDemo.main(ByteArrayStreamDemo.java:26)

while((len=bis.read())!=-1)

内存溢出，把代码贴出来吧