如何查看应用程序正在使用的当前堆大小？

使用此代码：

// Get current size of heap in byteslong heapSize = Runtime.getRuntime().totalMemory();// Get maximum size of heap in bytes. The heap cannot grow beyond this size.// Any attempt will result in an OutOfMemoryException.long heapMaxSize = Runtime.getRuntime().maxMemory(); // Get amount of free memory within the heap in bytes. This size will increase // after garbage collection and decrease as new objects are created.long heapFreeSize = Runtime.getRuntime().freeMemory();

知道这一点对我很有用。