Java字节流

一、输入流

 代码模板：

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

public class StreamTest {
    public static void main(String[] args) {
        FileInputStream inputStream = null;
        try {
            inputStream = new FileInputStream("E:/JavaTest/TestText.txt");
        } catch (FileNotFoundException e) {
            throw new RuntimeException(e);
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                }   catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
        }
    }
}

简化后：

import java.io.FileInputStream;
import java.io.IOException;

public class StreamTest {
    public static void main(String[] args) {
        try (FileInputStream inputStream = new FileInputStream("E:/JavaTest/TestText.txt")) {
        } catch (IOException e) {
            throw new RuntimeException(e);
        } 
    }
}

读取方法：

方法一：
int i;
while((i = inputStream.read()) != -1)    print((char) i);

方法二：
byte[] buffer = new byte[2];
while(inputStream.read(buffer) != -1)    print(new String(buffer));

inputStream.skip(n)    //跳过

 二、输出流

import java.io.FileOutputStream;
import java.io.IOException;

public class StreamTest {
    public static void main(String[] args) {
        try (FileOutputStream outputStream = new FileOutputStream("E:/JavaTest/TestText.txt")) {
            //追加：FileOutputStream outputStream = new FileOutputStream("E:/JavaTest/TestText.txt", true)
            outputStream.write("Hello Everybody".getBytes());
        } catch (IOException e) {
            throw new RuntimeException(e);
        } 
    }
}

三、综合

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

public class StreamTest {
    public static void main(String[] args) {
        try (FileInputStream inputStream = new FileInputStream("E:/JavaTest/TestText.txt")) {
            FileOutputStream outputStream = new FileOutputStream("E:/JavaTest/copy.txt");
            byte[] buffer = new byte[1024];
            int length;
            while ((length = inputStream.read(buffer)) != -1)   outputStream.write(buffer, 0, length);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}