java中createNewFile方法主要是如果该文件已经存在，则不创建，返回一个false，如果没有，则返回true，如下代码：
package com.yiibai;
import java.io.File;
public class FileDemo {
public static void main(String[] args) {
File f = null;
boolean bool = false;
try{
// create new file
f = new File("test.txt");//在默认路径创建一个file类
// tries to create new file in the system
bool = f.createNewFile();//返回true或者false判断该文件是否已经创建好
// prints
System.out.println("File created: "+bool);
// deletes file from the system
f.delete();
// delete() is invoked
System.out.println("delete() method is invoked");
// tries to create new file in the system
bool = f.createNewFile();
System.out.println("File created: "+bool);
}catch(Exception e){
e.printStackTrace();
}
}
}
让我们编译和运行上面的程序，这将产生以下结果：
File created: false
delete() method is invoked
File created: true
