Java 7ファイル属性の操作方法

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Java 7ファイル属性の操作方法
作者:chszs,転載には明記が必要です.ブログのホームページ:http://blog.csdn.net/chszs
基礎的な文章を書く準備をしているが、Java 7は長い間出てきたが、多くのJavaプログラマーは初期のJava 5やJava 6にとどまり、Java 7の新しい特性を使用していない.Java 7のNIOパッケージを使用してファイル属性を読み込み、ファイル属性を変更する方法について説明します.詳細は次のとおりです.
1、ファイルの属性を読み取る

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.logging.Level;
import java.util.logging.Logger;

public class ReadFileAttribute1 {
	public static void main(String[] args){
		Path filePath = Paths.get("d:\\test.txt");
		try{
			BasicFileAttributes ra = Files.readAttributes(filePath, BasicFileAttributes.class);
			System.out.println("CREATION TIME:" + ra.creationTime());
			System.out.println("LAST ACCESS TIME:" + ra.lastAccessTime());
			System.out.println("FILE SIZE:" + ra.size());
			System.out.println("LAST MODIFIED:" + ra.lastModifiedTime());
			System.out.println("IS SYSBOLIC LINK:" + ra.isSymbolicLink());
			System.out.println("IS FOLDER:" + ra.isDirectory());
			System.out.println("IS FILE:" + ra.isRegularFile());
			
		}catch(IOException e){
			Logger.getLogger(ReadFileAttribute1.class.getName()).log(Level.SEVERE, null, e);
		}
	}
}

出力:
CREATION TIME:2013-04-09T05:45:30.685152Z
LAST ACCESS TIME:2013-08-12T00:30:43.19369Z
FILE SIZE:32
LAST MODIFIED:2013-12-10T13:35:08.438828Z
IS SYSBOLIC LINK:false
IS FOLDER:false
IS FILE:true
2、ファイルの属性を読み取る別の方法

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.logging.Level;
import java.util.logging.Logger;

public class ReadFileAttribute2 {
	public static void main(String[] args){
		Path fp = Paths.get("D:\\test.txt");
		try{
			Files.getAttribute(fp, "basic:size");
			System.out.println("CREATION TIME:" + Files.getAttribute(fp, "basic:creationTime").toString());
			System.out.println("LAST ACCESS TIME:" + Files.getAttribute(fp, "basic:lastAccessTime").toString());
			System.out.println("FILE SIZE:" + Files.getAttribute(fp, "basic:size").toString());
			System.out.println("LAST MODIFIED:" + Files.getAttribute(fp, "basic:lastModifiedTime").toString());
			System.out.println("IS SYSBOLIC LINK:" + Files.getAttribute(fp, "basic:isSymbolicLink").toString());
			System.out.println("IS FOLDER:" + Files.getAttribute(fp, "basic:isDirectory").toString());
			System.out.println("IS FILE:" + Files.getAttribute(fp, "basic:isRegularFile").toString());
		}catch(IOException e){
			Logger.getLogger(ReadFileAttribute2.class.getName()).log(Level.SEVERE, null, e);
		}
		
	}
}

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.BasicFileAttributes;
import java.nio.file.attribute.FileTime;
import java.util.logging.Level;
import java.util.logging.Logger;

public class UpdateFileAttribute1 {
	public static void main(String[] args){
		Path fp = Paths.get("D:\\test.txt");
		try{
			BasicFileAttributes ra = Files.readAttributes(fp, BasicFileAttributes.class);
			long currentTimeMillis = System.currentTimeMillis();
			FileTime fileTime = FileTime.fromMillis(currentTimeMillis);
			Files.setAttribute(fp, "basic:creationTime", fileTime);
			FileTime creationTime = (FileTime)Files.getAttribute(fp, "basic:creationTime");
			System.out.println("NEW CREATION TIME:" + creationTime.toString());
			System.out.println("OLD CREATION TIME:" + ra.creationTime());
		}catch(IOException e){
			Logger.getLogger(UpdateFileAttribute1.class.getName()).log(Level.SEVERE, null, e);
		}
	}
}

出力:
NEW CREATION TIME:2013-12-10T15:04:26.159ZOLD CREATION TIME:2013-04-09T05:45:30.685152Z
4、ファイルの別の属性を変更することもできます

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.BasicFileAttributes;
import java.nio.file.attribute.FileTime;
import java.util.logging.Level;
import java.util.logging.Logger;

public class UpdateFileAttribute2 {
	public static void main(String[] args){
		Path fp = Paths.get("D:\\test.txt");
		try{
			BasicFileAttributes ra = Files.readAttributes(fp, BasicFileAttributes.class);
			long currentTimeMillis = System.currentTimeMillis();
			FileTime fileTime = FileTime.fromMillis(currentTimeMillis);
			Files.setAttribute(fp, "basic:lastAccessTime", fileTime);
			FileTime creationTime = (FileTime)Files.getAttribute(fp, "basic:lastAccessTime");
			System.out.println("NEW LAST-ACCESS-TIME:" + creationTime.toString());
			System.out.println("OLD LAST-ACCESS-TIME:" + ra.lastAccessTime());
		}catch(IOException e){
			Logger.getLogger(UpdateFileAttribute2.class.getName()).log(Level.SEVERE, null, e);
		}
	}
}

出力:
NEW LAST-ACCESS-TIME:2013-12-10T15:07:46.261ZOLD LAST-ACCESS-TIME:2013-08-12T00:30:43.19369Z
5、ファイルの属性を変更する別の方法

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.nio.file.attribute.BasicFileAttributes;
import java.nio.file.attribute.FileTime;
import java.util.logging.Level;
import java.util.logging.Logger;

public class UpdateFileAttribute3 {
	public static void main(String[] args){
		Path fp = Paths.get("D:\\test.txt");
		try{
			BasicFileAttributes ra = Files.readAttributes(fp, BasicFileAttributes.class);
			long currentTimeMillis = System.currentTimeMillis();
			FileTime fileTime = FileTime.fromMillis(currentTimeMillis);
			Files.setLastModifiedTime(fp, fileTime);
			FileTime time = (FileTime)Files.getAttribute(fp, "basic:lastModifiedTime");
			System.out.println("NEW LAST-MODIFIED-TIME:" + time.toString());
			System.out.println("OLD LAST-MODIFIED-TIME:" + ra.lastModifiedTime());
		}catch(IOException e){
			Logger.getLogger(UpdateFileAttribute3.class.getName()).log(Level.SEVERE, null, e);
		}
	}
}

出力:
NEW LAST-MODIFIED-TIME:2013-12-10T15:13:07.134Z
OLD LAST-MODIFIED-TIME:2013-12-10T13:35:08.438828Z

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