在此示例中，我们将展示如何使用File类的delete()方法删除文件或目录。 如果文件或目录已成功删除，则delete()方法返回true; 否则返回false。

下面是File.delete()的一个例子。

文件：DeleteFileDirectoryExample.java - 

package com.yiibai.tutorial.io;

import java.io.File;

/**
 * @author yiibai
 * DeleteFileDirectoryExample.java
 * Nov 2, 2016
 */
public class DeleteFileDirectoryExample {
    public static void main(String[] args) {

        /*Delete single file*/
        System.out.println("-------------Deleting single file--------------");
        File file=new File("test.txt");
        if(file.exists()){
            if(file.delete()){
                System.out.println("File deleted successfully");
            }else{
                System.out.println("Fail to delete file");
            }
        }

        System.out.println("\n-------------Deleting multiple files--------------");
        /*Delete all files in directory*/
        File folder=new File("folder");
        if(folder.exists() && folder.isDirectory()){

            for (File f : folder.listFiles()) {
                if(f.delete()){
                    System.out.println("'"+f.getName()+"' deleted successfully");
                }else{
                    System.out.println("Fail to delete '"+f.getName()+"'");
                }
            }
        }

        /*Delete folder*/
        System.out.println("\n-------------Deleting folder--------------");
        if(folder.exists() && folder.isDirectory()){
            if(folder.delete()){
                System.out.println("Folder deleted successfully");
            }else{
                System.out.println("Fail to delete folder");
            }
        }
    }
}

执行上面示例代码，得到以下结果：

-------------Deleting single file--------------
File deleted successfully

-------------Deleting multiple files--------------
'test.txt' deleted successfully
'test2.txt' deleted successfully
'test3.txt' deleted successfully
'test4.txt' deleted successfully
'test5.txt' deleted successfully
'test6.txt' deleted successfully
'test7.txt' deleted successfully

-------------Deleting folder--------------
Folder deleted successfully