Educoder -Java高级特性 - IO流

package step2;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
//读取src/step2/input/目录下的task.txt文件信息并输出到控制台，使用Java代码将字符串learning practice写入到src/step2/output/目录下的output.txt，若文件目录不存在，则创建该目录。
//注意：临时字节数组需要定义长度为8位，否则会有空格。
public class Task {
    
    public void task() throws IOException{
        /********* Begin *********/
        
        File file = new File("src/step2/input/task.txt");
        FileInputStream fs =new FileInputStream(file);
        byte[] b =new byte[8];
        fs.read(b);
        String str = new String(b,"UTF-8");
        System.out.println(str);


      
        
        File dir = new File("src/step2/output");
        if(!dir.exists()){
            dir.mkdir();
        }
        FileOutputStream out = new FileOutputStream("src/step2/output/output.txt"); //创建输出流
        String str1 = "learning practice";
        byte[] c = str1.getBytes();   //将字符串转换成字节
        out.write(c);                 //写数据
        out.flush();                  //刷新缓存区数据
        fs.close();                      //释放资源
        out.close();

        
}
}

package step3;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class Task {
    
    public void task() throws IOException{
        /********* Begin *********/
        String file1 = "src/step3/input/input.txt";
        FileReader fr = new FileReader(file1);
        char[] ch = new char[8];
        fr.read(ch);

        String file2 = "src/step3/output/output.txt";
        FileWriter fw = new FileWriter(file2);
        fw.write(ch);
        
        fr.close();
        fw.flush();
        fw.close();

        
        
        
        
        /********* End *********/        
    }
}

package step4;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;

public class Task {
    
    public void task() throws IOException{
        /********* Begin *********/
            String file1 = "src/step4/input/input.txt";
        FileInputStream fr = new FileInputStream(file1);
        byte[] b = new byte[1024];
        int len = 0;

        String file2 = "src/step4/output/output.txt";
        FileOutputStream fw = new FileOutputStream(file2);
        while((len = fr.read(b))!=-1){
            fw.write(b,0,len);
        }
        fr.close();
        fw.close();

        String file3 = "src/step4/input/input.jpg";
        String file4 = "src/step4/output/output.jpg";
        FileInputStream fs = new FileInputStream(file3); //定义文件输入流读取文件信息
        FileOutputStream fos = new FileOutputStream(file4);//定义文件输出流写文件
        len = 0;        //每次读取数据的长度
        byte[] bys = new byte[1024];    //数据缓冲区
        while( (len = fs.read(bys)) != -1){
            fos.write(bys, 0, len);
        }
        //释放资源  刷新缓冲区
        fs.close();
        fos.close();


        
        
        /********* End *********/        
    }
}