Java File createTempFile()用法及代碼示例

createTempFile()函數在給定目錄中創建一個臨時文件(如果未提及目錄，則選擇默認目錄)，該函數使用作為參數傳遞的前綴和後綴生成文件名。如果後綴為null，則該函數使用“.tmp”作為後綴。然後該函數返回創建的文件

函數簽名：

1. public static File createTempFile(String PREFIX, String SUFFIX)

OR

2. public static File createTempFile(String PREFIX, String SUFFIX, File DIR)

用法:

1. File.createTempFile(String, String, FILE);

2. File.createTempFile(String, String);

參數：該函數是一個重載函數，因此一個函數帶有後綴，前綴和File對象，而另一個函數僅帶有後綴和前綴。前綴不得少於三個字符，但後綴可以為null且如果未指定目錄，則為傳遞一個空值，然後該函數使用默認目錄。

返回類型：該函數返回表示新創建的臨時文件的抽象文件名

異常：該方法拋出：

IllegalArgumentException：如果prefix參數包含少於三個字符
IOExcetion：是否有IO錯誤(無法創建文件)
SecurityException：如果該方法不允許創建文件

以下示例程序旨在說明createTempFile()函數的用法：

範例1：如果我們提供前綴字符串並提供空後綴字符串

// Java program to demonstrate 
// createTempFile() method of File Class 
  
import java.io.*; 
  
public class solution { 
    public static void main(String args[]) 
    { 
  
        try { 
            // create a temp file 
            File f 
                = File.createTempFile("geeks", null); 
  
            // check if the file is created 
            if (f.exists()) { 
  
                // the file is created 
                // as the function retruned true 
                System.out.println("Temp File created: "
                                   + f.getName()); 
            } 
  
            else { 
  
                // display the file cannot be created 
                // as the function returned false 
                System.out.println("Temp File cannot be created: "
                                   + f.getName()); 
            } 
        } 
  
        catch (Exception e) { 
  
            // display the error message 
            System.err.println(e); 
        } 
    } 
}

輸出：

Temp File created: geeks7503529537487244659.tmp

範例2：如果我們提供前綴字符串和後綴字符串

// Java Program to demonstrate 
// createTempFile() method 
  
import java.io.*; 
  
public class solution { 
  
    public static void main(String args[]) 
    { 
        try { 
  
            // create a temp file 
            File f = File.createTempFile("geeks", ".SVP"); 
  
            // check if the file is created 
            if (f.exists()) { 
  
                // the file is created 
                // as the function retruned true 
                System.out.println("Temp File created: "
                                   + f.getName()); 
            } 
  
            else { 
  
                // display the file cannot be created 
                // as the function returned false 
                System.out.println("Temp File cannot be created: "
                                   + f.getName()); 
            } 
        } 
  
        catch (Exception e) { 
  
            // display the error message 
            System.err.println(e); 
        } 
    } 
}

輸出：

Temp File created: geeks4425780422923344328.SVP

範例3：如果提供前綴字符串，後綴字符串和目錄

// Java Program to demonstrate 
// createTempFile() method 
  
import java.io.*; 
  
public class solution { 
  
    public static void main(String args[]) 
    { 
        try { 
            // create a temp file 
            File f = File.createTempFile("geeks", 
                                         ".SVP", 
                                         new File("F:")); 
  
            // check if the file is created 
            if (f.exists()) { 
  
                // the file is created 
                // as the function retruned true 
                System.out.println("Temp File created: "
                                   + f.getAbsolutePath()); 
            } 
  
            else { 
  
                // display the file cannot be created 
                // as the function returned false 
                System.out.println("Temp File cannot be created: "
                                   + f.getAbsolutePath()); 
            } 
        } 
  
        catch (Exception e) { 
  
            // display the error message 
            System.err.println(e); 
        } 
    } 
}

輸出：

Temp File created: F:\geeks7006753451952178741.SVP

注意：程序可能無法在在線IDE中運行。請使用離線IDE並設置文件的路徑。

相關用法

注：本文由純淨天空篩選整理自andrew1234大神的英文原創作品 File createTempFile() method in Java with Examples。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。