nio(三)--文件读取和写入

来源：互联网发布：工商联副主席知乎编辑：程序博客网时间：2024/05/18 14:13

读取：

 Path p4=Paths.get("E:\\版本控制1\\服务端\\2.txt" );        try (BufferedReader reader=Files.newBufferedReader(p4, StandardCharsets.UTF_8)){            String line;            while ((line=reader.readLine())!=null){                System.out.println(line);            }        }简化版读取：  List<String> contents=Files.readAllLines(p6);        contents.forEach(content->{            System.out.println(content);        });

写入：

try (BufferedWriter writer=Files.newBufferedWriter(p6,StandardCharsets.UTF_8)){            writer.write("春花秋月，暗语纷纷");        }

监测文件改变

 Path path=Paths.get("E:\\版本控制1");        WatchKey key=path.register(watcher, ENTRY_MODIFY);        while (true){            key=watcher.take();            for (WatchEvent<?> event:key.pollEvents()){                if (event.kind()==ENTRY_MODIFY){                    System.out.println(path.getFileName()+"改变了");                }            }            key.reset();        }

文件读取（通道，可选择位置）：

     Path p= Paths.get("E:\\版本控制1\\服务端\\2.txt");        ByteBuffer byteBuffer=ByteBuffer.allocate(1024);        FileChannel fileChannel=FileChannel.open(p,StandardOpenOption.READ);        long index=fileChannel.size()-2;        fileChannel.read(byteBuffer,index);        System.out.println(new String(byteBuffer.array(),StandardCharsets.UTF_8        )); Path p= Paths.get("E:\\版本控制1\\服务端\\2.txt");        ByteBuffer byteBuffer=ByteBuffer.allocate(1024);        AsynchronousFileChannel channel=AsynchronousFileChannel.open(p,StandardOpenOption.READ);        channel.read(byteBuffer, 0, byteBuffer, new CompletionHandler<Integer, ByteBuffer>() {            @Override            public void completed(Integer result, ByteBuffer attachment) {                System.out.println("duqu:"+result);            }            @Override            public void failed(Throwable exc, ByteBuffer attachment) {                System.out.println("cuowu");            }        });

阅读全文

0 0