java文件操作之Path,Paths,Files

java文件操作之Path,Paths,Files

java7中文件IO发生了很大的变化，专门引入了很多新的类：

import java.nio.file.DirectoryStream;

import java.nio.file.FileSystem;

import java.nio.file.FileSystems;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.nio.file.attribute.FileAttribute;

import java.nio.file.attribute.PosixFilePermission;

import java.nio.file.attribute.PosixFilePermissions;

在以前的操作中，主要通过File构造一个文件，然后将File作为入参，获取输入流等操作。Api的操作不是很流畅。在新的文件IO中，用Path取代了File，用Files作为一个操作类，并且封装了很多非常实用的Api,看完下面的示例，就会有一个新的理解。

package filespaths;

import org.junit.Test;

import java.io.*;

import java.net.URI;

import java.nio.charset.StandardCharsets;

import java.nio.file.FileSystems;

import java.nio.file.Files;

import java.nio.file.PaBdUqlUaLEqth;

import java.nio.file.Paths;

import java.nio.file.attribute.PosixFilePermission;

import java.util.HashSet;

import java.util.List;

import java.util.Set;

import java.util.stream.Stream;

/**

* @Author kingboy

* @Date 2017/4/13 11:05

* @Description Path is used to Path Sample

* @email kingboyworld@163.com

*/

public class PathTest {

private static String separator = File.separator;

/**

* 构建Path

*/

@Test

public void constructon(){

//1.Paths

Path path = Paths.get("/Users/kingboy/Desktop/");

Path path1 = Paths.get(URI.create("/Users/kingboy/Desktop/"));

//2.FileSystems

Path path2 = FileSystems.getDefault().getPath("/Users/kingboy/Desktop/");

//3.File

Path path3 = new File("/Users/kingboy/Desktop/").toPath();

}

/**

* 创建一个空文件/文件夹

* @throws IOException

*/

@Test

public void create() throws IOException {

//文件夹

Path path = Paths.get("/Users/kingboy/Desktop/hello");

if(!Files.exists(path)){

Files.createDirectory(path);

//创建多个目录

//Files.createDirectories(path);

}

//文件

Path path1 = Paths.get("/Users/kingboy/Desktop/helloFile");

if(Files.exists(path1)){

Files.createFile(path1);

}

}

/**

* 文件属性

*/

@Test

public void getFileProperties() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/text.txt");

System.out.println(Files.getLastModifiedTime(path));//最后修改时间

System.out.println(Files.getOwner(path));//拥有者

System.out.println(Files.getPosixFilePermissions(path));//权限

System.out.println(Files.size(path));//文件大小

}

/**

* 读取一个文本文件

*/

@Test

public void readText() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/text.txt");

//通过bufferedReader读取

BufferedReader bufferedReader = Files.newBufferedReader(path, StandardCharsets.UTF_8);//文件编码

StringBuilder sb = new StringBuilder();

String tempString = null;

while ((tempString = bufferedhttp://Reader.readLine())!=null){

sb = sb.append(tempString);

}

System.out.println(sb);

//通过Files方法readAllLines

List

strings.forEach(s -> System.out.print(s));

//输出结果

//adsfasdfasdfadsfasdfgsdfsdffsdfsdf

//adsfasdfasdfadsfasdfgsdfsdffsdfsdf

}

/**

* 拿到文件输入流

* @throws IOException

*/

@Test

public void getInputStream() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/text.txt");

InputStream inputStream = Files.newInputStream(path);

}

/**

* 文件写操作

*/

@Test

public void writeFile() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/writeFile");

BufferedWriter bufferedWriter = Files.newBufferedWriter(path);

String str = "write file test";

bufferedWriter.write(str);

bufferedWriter.flush();

bufferedWriter.close();

}

/**

* 遍历一个文件夹

*/

@Test

public void traverseDirectory() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/");

Stream list = Files.list(path);

list.forEach(p -> {

System.out.println(p.getFileName());

});

}

/**

* 遍历文件树

*/

@Test

public void traverseTree() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/");

Stream walk = Files.walk(path);

walk.forEach(path1 -> {

// System.out.println(path1.getRoot());//根目录

System.out.println(path1.getFileName());//文件名

// System.out.println(path1.getParent());//上级目录

// System.out.println(path1.getFileSystem());//文件系统

});

//还有种方式Files.walkFileTree()

}

/**

* 文件复制

*/

@Test

public void copyFile() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/text.txt");

Path path2 = Paths.get("/Users/kingboy/Desktop/hello.txt");

Files.copy(path,path2);

}

/**

* 读取权限见上面示例，设置权限

*/

@Test

public void writePermission() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/text.txt");

Set permissionSet = new HashSet<>();

permissionSet.add(PosixFilePermission.GROUP_WRITE);

permissionSet.add(PosixFilePermission.OWNER_EXECUTE);

Files.setPosixFilePermissions(path,permissionSet);

}

//还有很多其他操作Api,自己查看方法名，很容易就能分辨出功能。

}

希望本篇文章对需要的朋友有帮助

strings.forEach(s -> System.out.print(s));

//输出结果

//adsfasdfasdfadsfasdfgsdfsdffsdfsdf

//adsfasdfasdfadsfasdfgsdfsdffsdfsdf

}

/**

* 拿到文件输入流

* @throws IOException

*/

@Test

public void getInputStream() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/text.txt");

InputStream inputStream = Files.newInputStream(path);

}

/**

* 文件写操作

*/

@Test

public void writeFile() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/writeFile");

BufferedWriter bufferedWriter = Files.newBufferedWriter(path);

String str = "write file test";

bufferedWriter.write(str);

bufferedWriter.flush();

bufferedWriter.close();

}

/**

* 遍历一个文件夹

*/

@Test

public void traverseDirectory() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/");

Stream list = Files.list(path);

list.forEach(p -> {

System.out.println(p.getFileName());

});

}

/**

* 遍历文件树

*/

@Test

public void traverseTree() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/");

Stream walk = Files.walk(path);

walk.forEach(path1 -> {

// System.out.println(path1.getRoot());//根目录

System.out.println(path1.getFileName());//文件名

// System.out.println(path1.getParent());//上级目录

// System.out.println(path1.getFileSystem());//文件系统

});

//还有种方式Files.walkFileTree()

}

/**

* 文件复制

*/

@Test

public void copyFile() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/text.txt");

Path path2 = Paths.get("/Users/kingboy/Desktop/hello.txt");

Files.copy(path,path2);

}

/**

* 读取权限见上面示例，设置权限

*/

@Test

public void writePermission() throws IOException {

Path path = Paths.get("/Users/kingboy/Desktop/text.txt");

Set permissionSet = new HashSet<>();

permissionSet.add(PosixFilePermission.GROUP_WRITE);

permissionSet.add(PosixFilePermission.OWNER_EXECUTE);

Files.setPosixFilePermissions(path,permissionSet);

}

//还有很多其他操作Api,自己查看方法名，很容易就能分辨出功能。

}

希望本篇文章对需要的朋友有帮助

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