java8--IO工具类(java疯狂讲义3复习笔记)

public static void pathTest(){
Path path = Paths.get("~");
System.out.println(path);
System.out.println(path.getNameCount());
System.out.println(path.getRoot());
Path absolutePath = path.toAbsolutePath();
System.out.println(absolutePath);
System.out.println(absolutePath.getNameCount());
System.out.println(absolutePath.getFileSystem());
//依次打印父路径
absolutePath.forEach(name->System.out.println(name));
}

public static void filesTest() throws FileNotFoundException, IOException{
//复制文件
Files.copy(Paths.get("abc.txt"), new FileOutputStream("testFile/abc2.txt"));
//判断是否隐藏文件
System.out.println(Files.isHidden(Paths.get("abc.txt")));
//读取文件的所有行到list
List<String> lines = Files.readAllLines(Paths.get("abc.txt"));
lines.forEach (line -> System.out.println(line));
//文件大小
System.out.println(Files.size(Paths.get("abc.txt")));
//向文件里写入东西
List<String> poem = new ArrayList<String>();
poem.add("quzhinannnnnnnnnnn曲志楠南安安那那那那那");
poem.addAll(lines);
Files.write(Paths.get("testFile/path.txt"), poem, Charset.forName("utf-8"));
//列出文件目录下的所有文件(不递归)
Files.list(Paths.get("/")).forEach(Name -> System.out.println(Name));
//打印所有文件到控制台
Files.lines(Paths.get("abc.txt"),Charset.forName("utf-8")).forEach(line -> System.out.println(line));
//查看存储空间
FileStore fs = Files.getFileStore(Paths.get("/"));
System.out.println(fs.getTotalSpace());
}

public static void walkFileTree() throws IOException{
Files.walkFileTree(Paths.get("."), new SimpleFileVisitor<Path>() {

@Override
public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
// TODO Auto-generated method stub
// return super.preVisitDirectory(dir, attrs);
System.out.println("正在访问：" + dir + "目录");
return FileVisitResult.CONTINUE;
}

@Override
public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
// TODO Auto-generated method stub
// return super.visitFile(file, attrs);
System.out.println("\t正在访问" + file + "文件");
if (file.endsWith("LearnIO.java")) {
System.out.println("******找到目标文件LearnIO.java******");
return FileVisitResult.TERMINATE; // 找到了就终止
}
return FileVisitResult.CONTINUE; // 没找到继续找
}
});  ;
}

private static void WatchServiceTest() throws IOException, InterruptedException {
// TODO Auto-generated method stub
WatchService watchService = FileSystems.getDefault().newWatchService();
Paths.get(".").register(watchService,
StandardWatchEventKinds.ENTRY_CREATE,
StandardWatchEventKinds.ENTRY_DELETE,
StandardWatchEventKinds.ENTRY_MODIFY
);
while(true){
//获取下一个文件的变化事件
WatchKey key = watchService.take();
for(WatchEvent<?> event : key.pollEvents()){
System.out.println(event.context()+"文件发生了"
+event.kind()+"事件");
}
//重设WatchKey
boolean valid = key.reset();
//如果重设失败,退出监听
if(!valid){
break;
}
}
}