java

import org.testng.annotations.Test;

import java.io.File;

import java.io.IOException;

public class FileCreate {

public static void main(String[] args) {

}

@Test public void create1(){

String filePath = "D:\\file1.txt";

File file = new File(filePath);

try {

   file.createNewFile();

System.out.println("创建文件 1 成功");

} catch (IOException e) {

e.printStackTrace();

}

}

@Test public void create2(){

   File parentFile = new File("D:\\");

   String fileNane = "file2.txt";

File file = new File(parentFile, fileNane);

  try {

          file.createNewFile();

     System.out.println("文件 2 创建成功");

} catch (IOException e) {

throw new RuntimeException(e);

}

}

@Test public void create3(){

      String parentPath = "d:\\";

      String filePath = "file3.txt";

        File file = new File(parentPath, filePath);

try {

    file.createNewFile();

    System.out.println("文件 3 创建成功");

} catch (IOException e) {

      throw new RuntimeException(e);

 }

}

}

获取文件

import org.testng.annotations.Test;

import java.io.File;

public class FileInformation {

  public static void main(String[] args) {

  }

   @Test

public void Info(){

   File file = new File("D:\\file1.txt");

    System.out.println("文件名称："+file.getName());

     System.out.println("文件绝对路径："+file.getAbsolutePath());

    System.out.println("文件父目录："+file.getParent());

     System.out.println("文件大小(字节)："+file.length());

     System.out.println("文件是否存在："+file.exists());

      System.out.println("是否是文件："+file.isFile());

       System.out.println("是否是目录："+file.isDirectory());

    }

 }

Scanner 与 Println

import org.testng.annotations.Test; 

import java.util.Scanner;

public class scanPrintTest {

  public static void main(String[] args) {

   Scanner input = new Scanner(System.in);

     String str = input.next();

       System.out.println(str);

        System.out.println("hello world");

   }

 } 

import java.util.Scanner;

public class scanTest {

  public static void main(String[] args) {

  Scanner input =new Scanner(System.in);

    System.out.print("请输入一个 double 类型的数:");

      double d = input.nextDouble();

       System.out.println(d);

     System.out.print("请输入一个 int 类型的数:");

  int i = input.nextInt();

  System.out.println(i);

   System.out.print("请输入一个 string 类型的数:"); String s = input.next(); System.out.println(s);

  }

}