java_nio2_2_FILES_ getAttribute與readAttributes

Path path2 = Paths.get("/Users/user/tmp/JavaIo1ln.java");<===他是SymbolicLink檔

try {

BasicFileAttributes basicFileAttributes = Files.readAttributes(path2, BasicFileAttributes.class);

System.out.println(basicFileAttributes.isSymbolicLink());

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

以上會顯示false,他預設會去取得SymbolicLink真實的資源！

如果屬性填寫錯誤會出現java.lang.IllegalArgumentException: 'sized' not recognized

如下例：

Map<String, Object> myMpa = Files.readAttributes(path2, "sized");

sized是錯誤的參數

getAttribute

Files.getAttribute(path, "creationTime",LinkOption.NOFOLLOW_LINKS);

參數部分

1 要查詢屬性的Path

2 使用 [view-name:]attribute-name表示想找的屬性詳下面說明

3 是否要找連結檔的屬性

屬性設定：

預設view-name使用basic 如basic: creationTime

basic:對應類別

BasicFileAttributeView

Name
Type
"lastModifiedTime"
FileTime
"lastAccessTime"
FileTime
"creationTime"
FileTime
"size"
Long
"isRegularFile"
Boolean
"isDirectory"
Boolean
"isSymbolicLink"
Boolean
"isOther"
Boolean
"fileKey"
Object

dos:DosFileAttributeView


Name
Type
readonly
Boolean
hidden
Boolean
system
Boolean
archive
Boolean




posix:


PosixFileAttributeView

Name
Type
"permissions"
Set<PosixFilePermission>
"group"
GroupPrincipal




FileOwnerAttributeView

readAttributes





public static Map<String,Object> readAttributes(Path path,
String attributes,
 LinkOption... options)throws IOException



attributes:可以這樣設定

"*"
Read all basic-file-attributes.
"size,lastModifiedTime,lastAccessTime"
Reads the file size, last modified time, and last access time attributes.
"posix:*"
Read all POSIX-file-attributes.
"posix:permissions,owner,size"
Reads the POSX file permissions, owner, and file size.





public static <A extends BasicFileAttributes> A readAttributes(Path path,
                                               Class<A> type,
                                               LinkOption... options)
                                                    throws IOException

Usage Example: Suppose we want to read a file's attributes in bulk:
    Path path = ...
    BasicFileAttributes attrs = Files.readAttributes(path, BasicFileAttributes.class);