文件類布爾型createNewFile() (File Class boolean createNewFile())

• This method is available in package java.io.File.createNewFile().

  軟件包java.io.File.createNewFile()中提供了此方法。

• This method is used to create a new file by using createNewFile() method and this method is accessible with the File object.

  此方法用于通過使用createNewFile()方法創建新文件，并且該方法可通過File對象訪問。

• If a file is already exists i.e. the name of created file is already exists that means we are not allowed to create a file of same name.

  如果文件已經存在，即創建的文件名已經存在，則意味著我們不允許創建同名文件。

• The return type of this method is Boolean i.e. it returns true or false if true that means file is successfully created and returns false that means the file already exists.

  此方法的返回類型為Boolean，即返回true或false，如果為true表示文件已成功創建，則返回false表示文件已存在。

Syntax:

句法：

    boolean createNewFile(){
}

Parameter(s):

參數：

We don't pass any object as a parameter in the method of the File.

我們不會在File方法中將任何對象作為參數傳遞。

Return value:

返回值：

The return type of this method is Boolean i.e. it returns true or false if true that means file is successfully created else returns false that means the file already exists.

此方法的返回類型為Boolean，即返回true或false，如果為true則表示文件已成功創建，否則返回false表示文件已存在。

Java程序，演示createNewFile()方法的示例 (Java program to demonstrate example of createNewFile() method)

// import the File class because we will use File class methods
import java.io.File;
// import the Exception class because it may raise an exception 
// when working with files
import java.lang.Exception;
public class CreateFile {
public static void main(String[] args) {
try {
// Specify the path of file and we use double slashes 
// to escape '\' character sequence for windows otherwise 
// it will be considerable as url.
File file1 = new File("C:\\Users\\computer clinic\\OneDrive\\Articles\\javafiles.txt");
File file2 = new File("C:\\Users\\computer clinic\\OneDrive\\Articles\\myjava.txt");
// By using createNewFile()create a new file named 
// javafiles.txt because file is not exists 
// (i.e it returns true) so this method creates empty file.
if (file1.createNewFile())
System.out.println("File created Successfully" + " " + file1.getName());
else
System.out.println("File already exists " + file1.getName());
// By using createNewFile() is not create a new file 
// named myjava.txt because the name of this file is 
// already exists(i.e. it returns false) so we will 
// get a message File already exists .
if (file2.createNewFile())
System.out.println("File created Successfully" + file2.getName());
else
System.out.println("File already exists" + " " + file2.getName());
} catch (Exception e) {
System.out.println("An error occurred.");
e.printStackTrace();
}
}
}

Output

輸出量

D:\Programs>javac CreateFile.java
D:\Programs>java CreateFile
File already exists C:\Users\computer clinic\OneDrive\Articles\javafiles.txt
File already exists C:\Users\computer clinic\OneDrive\Articles\myjava.txt

翻譯自: https://www.includehelp.com/java/file-class-boolean-createnewfile-method-with-example.aspx