Java 示例 - 创建新文件

• 

  问题描述

  如何创建一个新文件？
• 

  解决方案

  此示例演示了使用 File() 构造函数和 File 类的 file.createNewFile() 方法创建新文件的方法。

  
  import java.io.File;
  import java.io.IOException;
  public class Main {
     public static void main(String[] args) {
        try {
           File file = new File("C:/myfile.txt");
           
           if(file.createNewFile())System.out.println("Success!");
           else System.out.println ("Error, file already exists.");
        }
        catch(IOException ioe) {
           ioe.printStackTrace();
        }
     }
  }
  

• 

  结果

  上面的代码示例会产生如下结果（如果“myfile.txt之前不存在）

  
  Success!
  

  下面是另一个文件创建示例

  
  import java.io.IOException;
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.FileWriter;
  import java.io.IOException;
  import java.nio.charset.StandardCharsets;
  import java.nio.file.Files;
  import java.nio.file.Paths;
  import java.nio.file.StandardOpenOption;
  import java.util.Arrays;
  import java.util.List;
  public class JavaApplication1 { 
     public static void main(String[] args) throws IOException {
        createFileUsingFileClass();
        createFileUsingFileOutputStreamClass();
        createFileIn_NIO();
        // TODO code application logic here
     } 
     private static void createFileUsingFileClass() throws IOException { 
        File file = new File("c://testFile1.txt");
        
        //Create the file
        if (file.createNewFile()) { 
           System.out.println("File is created!");
        } else {
           System.out.println("File already exists.");
        } 
        
        //Write Content
        FileWriter writer = new FileWriter(file);
        writer.write("Test data");
        writer.close();
     } 
     private static void createFileUsingFileOutputStreamClass() throws IOException { 
        String data = "Test data";
        FileOutputStream out = new FileOutputStream("c://testFile2.txt");
        out.write(data.getBytes());
        out.close();
     } 
     private static void createFileIn_NIO()  throws IOException { 
        String data = "Test data";
        Files.write(Paths.get("c://testFile3.txt"), data.getBytes());
        List<String> lines = Arrays.asList("1st line", "2nd line");
        Files.write(Paths.get(
           "file6.txt"), lines, StandardCharsets.UTF_8, 
           StandardOpenOption.CREATE, StandardOpenOption.APPEND);
     }
  }