Java中FileOutputStream类的使用

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

public class FileOutputStreamDemo {
    public static void main(String[] args) throws FileNotFoundException {
        FileOutputStream fos = new FileOutputStream("D:\\新建文件夹\\a.txt");
    }
}

public class FileOutputStreamDemo {
    public static void main(String[] args) throws IOException {
        //IOException是FileNotFoundException的父类，因此只写IOException即可
        FileOutputStream fos = new FileOutputStream("D:\\新建文件夹\\a.txt");
        //传入的是int类型数据，但实际写到文件中的是整数在ASCII上对应的字符
        fos.write(97);
        //相同的，抛出异常
    }
}

public class FileOutputStreamDemo {
    public static void main(String[] args) throws IOException {
        FileOutputStream fos = new FileOutputStream("D:\\新建文件夹\\a.txt");
        byte[] bytes1 = {97,98,99,100,101};
        fos.write(bytes1);
        //一次写入一个字节数组数据
    }
}

public class FileOutputStreamDemo {
    public static void main(String[] args) throws IOException {
        FileOutputStream fos = new FileOutputStream("D:\\新建文件夹\\a.txt");
        byte[] bytes1 = {97,98,99,100,101};
        fos.write(bytes1,2,4);
        //off:起始字节索引,len:写入的字节个数
    }
}

public class FileOutputStreamDemo {
    public static void main(String[] args) throws IOException {
        FileOutputStream fos = new FileOutputStream("D:\\新建文件夹\\a.txt");
        //创建一个字符串，内容为换行符
        fos.write(97);
        String str1 = "\r\n";//也可以只写\r或者\n但最好写完整
        //调用getBytes()方法，将字符串中内容转换为字节数组
        byte[] bytes1 = str1.getBytes();
        fos.write(bytes1);
        //同样的，可以用字符串的方式创建较长的数据，再调用getBytes()方法，转换为字节数组
        String str2 = "asdfghjklqwert";
        byte[] bytes2 = str2.getBytes();
        fos.write(bytes2);
    }
}

public class FileOutputStreamDemo {
    public static void main(String[] args) throws IOException {
        FileOutputStream fos = new FileOutputStream("D:\\新建文件夹\\a.txt");
        byte[] bytes1 = {97,98,99,100,101};
        fos.write(bytes1,2,4);
        //关流
        fos.close();
    }
}

import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
public class FileOutputStreamDemo {
    public static void main(String[] args) throws IOException {
        //创建输出流对象
        FileOutputStream fos = new FileOutputStream("D:\\新建文件夹\\a.txt",true);
        //写入续写数据
        String str = "asdfghjklqwert";
        byte[] bytes = str.getBytes();
        fos.write(bytes);
        //关流
        fos.close();
    }
}