Java-I/O流实验

Posted 2022-12-15 康小庄

1.编写文本文件复制程序，即把源文件复制到目标文件，运行时用参数方式输入源文件名和目标文件名，设入口主类为FileCopy，则运行方式为：java FileCopy 源文件名 目标文件名

FileCopy

public class FileCopy 
	public static void main(String[] args) 
		copyFile();
	

	public static void copyFile() 
		System.out.println("请输入源文件名 例如 f:\\\\\\\\1.txt");
		Scanner scanner = new Scanner(System.in);
		String srcFilePath = scanner.nextLine();
		System.out.println("请输入目标文件名 例如 f:\\\\\\\\1.txt");
		String desFilePath = scanner.nextLine();

		FileInputStream fis = null;
		FileOutputStream fos = null;
		try 
			fis = new FileInputStream(srcFilePath);
			fos = new FileOutputStream(desFilePath);
			// 定义字节数组
			byte[] buf = new byte[1024];
			int len = 0;
			while ((len = fis.read(buf)) != -1) 
				// 一遍读一边写
				fos.write(buf, 0, len);
			
			System.out.println("文件拷贝成功！！！");
		 catch (Exception e) 
			e.printStackTrace();
		 finally 
			try 
				fis.close();
				fos.close();
			 catch (IOException e) 
				// TODO Auto-generated catch block
				e.printStackTrace();
			
			scanner.close();
		
	

2.将任意两个文件合并到一个文件，要求采用java命令行方式在控制台按照“源文件1 源文件2 目标文件” 方式录入，注意多种异常处理。

FileMerge

public class FileMerge 

	public static void main(String[] args) 
		mergeFile();
	

	public static void mergeFile() 
		System.out.println("请输入源文件名1 例如 f:\\\\\\\\1.txt");
		Scanner scanner = new Scanner(System.in);
		String srcFilePath1 = scanner.nextLine();
		System.out.println("请输入源文件名2 例如 f:\\\\\\\\1.txt");
		String srcFilePath2 = scanner.nextLine();
		System.out.println("请输入目标文件名 例如 f:\\\\\\\\1.txt");
		String desFilePath = scanner.nextLine();

		byte[] buf = new byte[1024];
		int readData = 0;

		FileInputStream fileInputStream1 = null;
		FileInputStream fileInputStream2 = null;
		FileOutputStream fileOutputStream = null;
		try 
			fileInputStream1 = new FileInputStream(srcFilePath1);
			fileInputStream2 = new FileInputStream(srcFilePath2);
			fileOutputStream = new FileOutputStream(desFilePath, true);
			/*
			 * 从输入流最多读取b.length字节的数据到字节数组 返回-1 读取完毕 读取正常 返回实际读取的字节数
			 */
			while ((readData = fileInputStream1.read(buf)) != -1) 
				String str = new String(buf, 0, readData);
				System.out.println(new String(buf, 0, readData));// 显示
				fileOutputStream.write(str.getBytes("UTF-8"));
			
			while ((readData = fileInputStream2.read(buf)) != -1) 
				String str = new String(buf, 0, readData);
				System.out.println(new String(buf, 0, readData));// 显示
				fileOutputStream.write(str.getBytes("UTF-8"));
			
			System.out.println("文件合并成功");
		 catch (Exception e) 
			e.printStackTrace();
		 finally 
			try 
				scanner.close();
				fileInputStream1.close();
				fileInputStream2.close();
				fileOutputStream.close();
			 catch (IOException e) 
				e.printStackTrace();
			
		
	

3.编写程序实现将一个文件内容追加到另一个文件内容后，如将D盘file文件夹下的f1.txt追加到E盘根目录下的f2.txt中。(必须异常处理)

FileSupple

public class FileSupple 

	public static void main(String[] args) 
		suppleFile();
	

	public static void suppleFile() 
		System.out.println("请输入源文件名 例如 f:\\\\\\\\1.txt");
		Scanner scanner = new Scanner(System.in);
		String srcFilePath = scanner.nextLine();
		System.out.println("请输入目标文件名 例如 f:\\\\\\\\1.txt");
		String desFilePath = scanner.nextLine();

		byte[] buf = new byte[1024];
		int readData = 0;

		FileInputStream fileInputStream = null;
		FileOutputStream fileOutputStream = null;
		try 
			fileInputStream = new FileInputStream(srcFilePath);
			fileOutputStream = new FileOutputStream(desFilePath, true);
			/*
			 * 从输入流最多读取b.length字节的数据到字节数组 返回-1 读取完毕 读取正常 返回实际读取的字节数
			 */
			while ((readData = fileInputStream.read(buf)) != -1) 
				String str = new String(buf, 0, readData);
				// 显示
				System.out.println(new String(buf, 0, readData));
				fileOutputStream.write(str.getBytes("UTF-8"));
			
			System.out.println("文件追加成功");
		 catch (Exception e) 
			e.printStackTrace();
		 finally 
			try 
				scanner.close();
				fileInputStream.close();
				fileOutputStream.close();
			 catch (IOException e) 
				e.printStackTrace();