@Test public?void?clientSocket()?throws?IOException?{ ????SocketChannel?socketChannel?=?SocketChannel.open(new?InetSocketAddress("localhost",?9999)); ????socketChannel.configureBlocking(false); ????ByteBuffer?byteBuffer?=?ByteBuffer.allocate(1024); ????byteBuffer.put("你好好好好".getBytes()); ????byteBuffer.flip(); ????socketChannel.write(byteBuffer); ????byteBuffer.clear(); ????socketChannel.shutdownOutput(); ????socketChannel.close(); } @Test public?void?serverSocket()?throws?IOException?{ ????ServerSocketChannel?serverSocketChannel?=?ServerSocketChannel.open(); ????serverSocketChannel.configureBlocking(false); ????serverSocketChannel.bind(new?InetSocketAddress(9999)); ????Selector?selector?=?Selector.open(); ????//?注冊連接事件 ????serverSocketChannel.register(selector,?SelectionKey.OP_ACCEPT); ????while?(selector.select()?>?0)?{ ????????Set<SelectionKey>?selectionKeySet?=?selector.selectedKeys(); ????????System.out.println(selectionKeySet.size()); ????????Iterator<SelectionKey>?iterator?=?selectionKeySet.iterator(); ????????while?(iterator.hasNext())?{ ????????????SelectionKey?selectionKey?=?iterator.next(); ????????????if?(selectionKey.isAcceptable())?{ ????????????????System.out.println("accept====="); ????????????????SocketChannel?socketChannel?=?serverSocketChannel.accept(); ????????????????socketChannel.configureBlocking(false); ????????????????socketChannel.register(selector,?SelectionKey.OP_READ); ????????????}?else?if?(selectionKey.isReadable())?{ ???????????????????? ????????????????System.out.println("read====="); ????????????????SocketChannel?socketChannel?=?(SocketChannel)?selectionKey.channel(); ????????????????ByteBuffer?byteBuffer?=?ByteBuffer.allocate(1024); ????????????????socketChannel.read(byteBuffer); ????????????????byteBuffer.flip(); ????????????????System.out.println(new?String(byteBuffer.array())?+?":::::::::::::::::::"); ????????????????byteBuffer.clear(); ????????????} ????????????iterator.remove(); ????????????System.out.println(selectionKeySet.size()); ????????} ????} }在client結束后，我末尾打印的selectionKeySet.size()方法，本來是0，結果循環一遍siez卻變成1了，仍然會不停的進入selectionKey.isReadable()方法，導致死循環最后iterator應該是移除掉了，但集合里面總有一個SelectionKeyImp的對象，這個是哪里來的？我末尾打印的selectionKeySet.size()方法，本來是0，結果循環一遍又這是控制臺：1 [sun.nio.ch.SelectionKeyImpl@4b9e13df] accept===== 0 1 [sun.nio.ch.SelectionKeyImpl@2b98378d] read===== 你好好好好?? 0 1 [sun.nio.ch.SelectionKeyImpl@2b98378d] read=====??????? ???? 0 1 [sun.nio.ch.SelectionKeyImpl@2b98378d] read=====??????? ? 0 1 [sun.nio.ch.SelectionKeyImpl@2b98378d] read=====????? 0 1 [sun.nio.ch.SelectionKeyImpl@2b98378d] read=====