字节输入流

==Inputstream==

package com.bilibili;

import java.io.*;
import java.util.Arrays;
import java.util.Scanner;

/**
 * @author WangYH
 * @version 2021.1.3
 * @date 2023/4/7 15:19
 */
public class Main {
   
    public static void main(String[] args) {
   

        String path = "C:" + File.separator + "Users" + File.separator + "i'li'ke'stay"+File.separator + "Desktop"+File.separator + "java_IO_test" + File.separator + "hello.txt";

        try(FileInputStream stream = new FileInputStream(path)) {
   

            //字节流

            byte[] b1 = new byte[stream.available()];
            //返回可读字节
            stream.read(b1,0,3);

            //仅限于纯文本文件，其他的可能会乱码
            System.out.println(stream.available());
            System.out.println(new String(b1));


            //跳过指定字节数,这个流是一次性的，不能反向
            stream.skip(4);
            System.out.println((char) stream.read());

        }catch (IOException e) {
   
                e.printStackTrace();
            }
        }
}

字节输出流

package com.bilibili;

import java.io.*;
import java.util.Arrays;
import java.util.Scanner;

/**
 * @author WangYH
 * @version 2021.1.3
 * @date 2023/4/7 15:19
 */
public class Main {
   
    public static void main(String[] args) {
   

        String path = "C:" + File.separator + "Users" + File.separator + "i'li'ke'stay"+File.separator + "Desktop"+File.separator + "java_IO_test" + File.separator + "hello.txt";

        try(FileOutputStream stream = new FileOutputStream(path,true)) {
   
            //初始化时，加入true ,表示追加模式

            //字节流

            stream.write("hello,world!".getBytes(),3,3);
            //刷新操作，将缓冲区数据写入指定路径,立即生效
            stream.flush();

        }catch (IOException e) {
   
                e.printStackTrace();
            }
        }
}

字节流实现文件拷贝

package com.bilibili;

import java.io.*;
import java.util.Arrays;
import java.util.Scanner;

/**
 * @author WangYH
 * @version 2021.1.3
 * @date 2023/4/7 15:19
 */
public class Main {
   
    public static void main(String[] args) {
   

        String path = "D:" + File.separator + "Download" + File.separator + "NeverBeFar.mp4";

        try (FileInputStream input = new FileInputStream(path)) {
   
            //创建输入输出流
            FileOutputStream output = new FileOutputStream("copy.mp4");

           byte[] buffer = new byte[1024];
           int len;
           while ((len = input.read(buffer)) != -1){
   
               output.write(buffer, 0, len);
           }

           //大小一样，正常执行，拷贝完成

        } catch (FileNotFoundException e) {
   
            e.printStackTrace();
        } catch (IOException e) {
   
            e.printStackTrace();
        }
    }
}

字符输入流

package com.bilibili;

import java.io.*;
import java.util.Arrays;
import java.util.Scanner;

/**
 * @author WangYH
 * @version 2021.1.3
 * @date 2023/4/7 15:19
 */
public class Main {
   
    public static void main(String[] args) {
   

       //字符流，只适合读取纯文本文件，因为是以一个具体的字符读取，其他类型不适用

        String path = "C:" + File.separator + "Users" + File.separator + "i'li'ke'stay"+File.separator + "Desktop"+File.separator + "java_IO_test" + File.separator + "hello.txt";

        try(FileReader reader = new FileReader(path)) {
   
            //读取一个字符
            System.out.println((char) reader.read());

            System.out.println((char) reader.read());


        } catch (FileNotFoundException e) {
   
            e.printStackTrace();
        } catch (IOException e) {
   
            e.printStackTrace();
        }
    }
}

字符输出流

package com.bilibili;

import java.io.*;
import java.util.Arrays;
import java.util.Scanner;

/**
 * @author WangYH
 * @version 2021.1.3
 * @date 2023/4/7 15:19
 */
public class Main {
   
    public static void main(String[] args) {
   

       //字符流，只适合读取纯文本文件，因为是以一个具体的字符读取，其他类型不适用

        String path = "C:" + File.separator + "Users" + File.separator + "i'li'ke'stay"+File.separator + "Desktop"+File.separator + "java_IO_test" + File.separator + "hello.txt";

        try(FileWriter writer = new FileWriter(path,true)) {
   
            //以字符作为操作单位
            writer.write("Hello World!");
            writer.append("hello,").append("world");
            writer.flush();
        } catch (IOException e) {
   
            e.printStackTrace();
        }
    }
}

字符流拷贝

package com.bilibili;

import java.io.*;
import java.util.Arrays;
import java.util.Scanner;

/**
 * @author WangYH
 * @version 2021.1.3
 * @date 2023/4/7 15:19
 */
public class Main {
   
    public static void main(String[] args) {
   

       //字符流，只适合读取纯文本文件，因为是以一个具体的字符读取，其他类型不适用

        String path = "C:" + File.separator + "Users" + File.separator + "i'li'ke'stay"+File.separator + "Desktop"+File.separator + "java_IO_test" + File.separator + "hello.txt";

       try(FileReader reader = new FileReader(path)) {
   
         FileWriter writer = new FileWriter("copy.txt");
         char[] ch = new char[3];
         int len = reader.read(ch);
         while (len != -1) {
   
             //这里输出一定要按实际长度来复制，不要定义一个固定长度
             writer.write(ch, 0, len);
             len = reader.read(ch);
         }
         writer.close();
         reader.close();
       } catch (FileNotFoundException e) {
   
           e.printStackTrace();
       } catch (IOException e) {
   
           e.printStackTrace();
       }
    }
}