【java】io流之字节输出流：java.io.OutputStream类及子类java.io.FileOutputStream

package 文件操作;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class TestOutputStream {
    public static void main(String[] args) throws IOException {
        File file=new File("D:"+File.separator+"test.txt");
        OutputStream outputStream=new FileOutputStream(file);
        String str="每天进步一点点！";
        byte[] bytes=str.getBytes();
        outputStream.write(bytes);
        outputStream.close();
    }
}

package 文件操作;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class TestOutputStream {
    public static void main(String[] args) throws IOException {
        File file=new File("D:"+File.separator+"test.txt");
        OutputStream outputStream=new FileOutputStream(file);
        String str="让世界充满爱！";
        byte[] bytes=str.getBytes();
        
//        outputStream.write(bytes);
        
        for(byte b:bytes){
            outputStream.write(b);//单个字节输出
        }
        
        outputStream.close();
    }
}

package 文件操作;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class TestOutputStream {
    public static void main(String[] args) throws IOException {
        File file=new File("D:"+File.separator+"test.txt");
        OutputStream outputStream=new FileOutputStream(file);
        String str="让世界充满爱！";
        byte[] bytes=str.getBytes();
//        outputStream.write(bytes, 1, 3);//这样输出中文会有乱码:檬?
        outputStream.write(bytes, 2, 4);//输出：世界
        outputStream.close();
    }
}

package 文件操作;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class TestOutputStream {
    public static void main(String[] args) throws IOException {
        File file=new File("D:"+File.separator+"test.txt");
        OutputStream outputStream=new FileOutputStream(file,true);//文件内容追加，而不是覆盖。
        String str="让世界充满爱！";
        byte[] bytes=str.getBytes();
        outputStream.write(bytes);
        outputStream.close();
    }
}

package 文件操作;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

public class TestOutputStream {
    public static void main(String[] args) throws IOException {
        File file=new File("D:"+File.separator+"test.txt");
        OutputStream outputStream=new FileOutputStream(file,true);//文件内容追加，而不是覆盖。
        String str="让世界充满爱！
";//每次输出写回文件换行
        byte[] bytes=str.getBytes();
        outputStream.write(bytes);
        outputStream.close();
    }
}

 字节流可以不用关闭操作即可将内容写进文件。