EduCoder Java程序设计---Java面向对象（第八章） - 文件类答案

爱被打了一巴掌 2023-09-29 13:22 1阅读 0赞

**第1关 [创建文件][Link 1]**

package step1;
    
    import java.io.File;
    import java.io.FileFilter;
    import java.io.IOException;
    import java.util.Scanner;
    
    public class Task {
    	
    	public void solution()          {
    		/********* Begin *********/
    		try{
    			File file1 = new File("src/output/hello.txt");
    			file1.createNewFile();
    			File file2 = new File("src/output/test.txt");
    			file2.createNewFile();
    		}catch(IOException e){
    			e.printStackTrace();
    		}
    		/********* End *********/
    	}
    }

**第2关 [文件的常用操作][Link 2]**

package step2;
    
    import java.io.File;
    import java.io.FileFilter;
    import java.io.IOException;
    import java.util.Arrays;
    public class Task {
    	public static void main(String[] args)throws IOException {
    		/********* Begin *********/
    		
    		File file1 = new File("src/test2");
    		file1.mkdir();
    		File file2 = new File("src/output/test2.txt");
    		file2.delete();
    		File file3 = new File("src/test2/helloworld.txt");
    		file3.createNewFile();
    		File file4 = new File("src/test2/step2.txt");
    		file4.createNewFile();
    
    
    		File dir = new File("src/output");
    		File[] files = dir.listFiles();
    		
    
    		System.out.println("output目录结构为：");
    		Arrays.sort(files);//这里用集合排序
    		for(File file : files){
    			System.out.println(file.getName());
    		}
    		System.out.println("test2目录结构为：");
    		File dir1 = new File("src/test2");
    		File [] files1 = dir1.listFiles();
    		for(File file : files1){
    			System.out.println(file.getName());
    		}
    		/********* End *********/
    	}
    }

**第3关 [文件查看器][Link 3]**

package step3;
    
    import java.io.File;
    import java.util.Arrays;
    public class Task {
    	
    	/********** Begin **********/
        int n = 1;
    	public void showDirStructure(File file)	{
            
            System.out.println("+--"+file.getName());
            File[] dir = file.listFiles();
            Arrays.sort(dir);
            for(File files : dir){
                if(files.isDirectory()){
                    for(int i = 0 ; i < n* 2;++i)
                        System.out.print(" ");
                        ++n;
                        showDirStructure(files);
                        --n;
                }
                else{
                    for(int i = 0 ; i < n*2; ++i)
                    System.out.print(" ");
                    System.out.println("--"+files.getName());
                }
            }
    		
    
    
    
    
    
    	}

**第4关 [图片查看器][Link 4]**

package step4;
    
    import java.io.File;
    
    import java.util.Arrays;
    public class Task {
    	
    	/********** Begin **********/
    	public void showDirStructure(File file)	{
    		if(file.isDirectory()){
    			System.out.println("+--"+file.getName());
    			}
    			int a = 2 ;
    			showDirTree(a,file);
    		}
    	public void showDirTree(int a , File file){
    		File[] files = file.listFiles();
    		Arrays.sort(files);
    		for(int i = 0 ; i < files.length; i ++){
    			if(files[i].isDirectory()){
    				for(int j = 0 ; j < a ; j++){
    					System.out.print(" ");
    				}
    				System.out.println("+--"+files[i].getName());
    				showDirTree(a+2,files[i]);
    			}else{
    				String fileName = files[i].getName().toLowerCase();
    				if(fileName.endsWith(".jpg")||fileName.endsWith(".png")||fileName.endsWith(".bmp")){
    					for(int j = 0 ; j < a; j++){
    						System.out.print(" ");
    					}
    					System.out.println("--"+files[i].getName());
    				}	
    			}
    		}
    	}
    	/********** End **********/
    }

[Link 1]: https://www.educoder.net/tasks/j9oi4lb5ft8v
[Link 2]: https://www.educoder.net/tasks/4sc6zffmjy52
[Link 3]: https://www.educoder.net/tasks/jorlpvbi93mk
[Link 4]: https://www.educoder.net/tasks/ex2mjiqkry3g