Java-IO流实验

package p1;
import java.util.*;
import java.io.*;
public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		System.out.println("请输入路径：");
		String path = scanner.next();
		File file = new File(path);
		if(file.isDirectory()) {//类型为目录时
			if(!file.exists()) {//目录不存在时
				System.out.println("该路径不存在!");
			}else {
				System.out.println("该文件夹下的路径如下：");
				String[] sub = file.list();//获取文件夹下的所有文件、文件夹
				for(String i:sub) {//输出
					System.out.println(i);
				}
			}
		}else {//不为目录时
			System.out.println("该路径不为目录!");
		}
	}
}

package p2;
import java.util.*;
import java.io.*;
public class Main {
	public static void main(String[] args)  throws Exception{
		Scanner scanner = new Scanner(System.in);
		System.out.println("1. 复制");
		System.out.println("2. 剪切");
		System.out.println("请选择: ");
		int choose = scanner.nextInt();
		System.out.println("源路径: ");
		String resource = scanner.next();
		System.out.println("目标路径: ");
		String target = scanner.next();
		if(choose==1) {//复制
			FileOperation.copy(resource,target);
		}else {//剪切
			FileOperation.cut(resource, target);
		}
		System.out.println("执行完毕");
	}
}
class FileOperation{//文件操作类
	public static void copy(String resource,String target)  throws Exception{//复制文件
		//文件流对象
		File file_resource = new File(resource);//源文件
		File file_target = new File(target);//目标文件
		//文件输入输出流对象
		FileInputStream fis = new FileInputStream(file_resource);//输入流，写入数据
		FileOutputStream fos = new FileOutputStream(file_target);//输出流，读取数据
		//读取文件数据
		byte[] buff_resource = new byte[(int) file_resource.length()];
		fis.read(buff_resource);//读取文件数据
		//写入文件数据
		String str = new String(buff_resource);
		byte[] buff_target = str.getBytes();
		fos.write(buff_target);//写入文件数据
		//关闭文件流
		fis.close();
		fos.close();
	}
	public static void cut(String resource,String target)  throws Exception{//剪切文件
		//文件流对象
		//File file_delete = new File(resource);//源文件
		File file_resource = new File(resource);//源文件
		File file_target = new File(target);//目标文件
		//文件输入输出流对象
		FileInputStream fis = new FileInputStream(file_resource);//输入流，读取数据
		FileOutputStream fos = new FileOutputStream(file_target);//输出流，写入数据
		//读取文件数据
		byte[] buff_resource = new byte[(int) file_resource.length()];
		fis.read(buff_resource);//读取文件数据
		//写入文件数据
		String str = new String(buff_resource);
		byte[] buff_target = str.getBytes();
		fos.write(buff_target);//写入文件数据
		//关闭文件流
		fis.close();
		fos.close();
		//删除源文件，必须先关闭fis文件流后才能成功删除文件
		file_resource.delete();
	}
}

package p3;
import java.io.*;
public class Main {
	public static void main(String[] args) throws IOException{
		String str = "2018 FIFA World Cup will play in Russia.";
		Write("D:\\data.txt",str);
		System.out.println(Read("D:\\data.txt"));
	}
	public static String Read(String filename) throws IOException{//文件读取
		File file = new File(filename);
		FileInputStream fis = new FileInputStream(file);//输入流，读取数据
		byte[] buff = new byte[(int) file.length()];
		fis.read(buff);//读取文件
		String str = new String(buff);
		fis.close();
		return str;
	}
	public static void Write(String filename,String str) throws IOException{//文件写入
		File file = new File(filename);
		FileOutputStream fos = new FileOutputStream(file);//输出流，写入数据
		byte[] buff = str.getBytes();
		fos.write(buff);//写入文件
		fos.close();
	}
}