补充:由于JDK1.4新增了nio,而nio的buffer分配内存比较特殊(读写流可以共享内存)。如果有大量数据交互,也可能导致java.lang.OutOfMemoryError。相应的JDK新增了一个特殊的参数:-XX:MaxDirectMemorySize 默认是64M,可以改大些如128M。
-XX:MaxDirectMemorySize=<size>
Specifies the maximum amount of memory in bytes that the Java™ NIO library can allocate for direct memory buffers. The default is 64 megabytes, which corresponds to
-XX:MaxDirectMemorySize=64m . The use of direct memory buffers can minimize the copying cost when doing I/O operations.