Java进阶核心之OutputStream流

Java进阶核心之OutputStream流

• OutputStream是输出字节流的父类&＃xff0c;它是一个抽象类

void write(int b)讲解&＃xff1a;将指定的字节写入输出流void write(byte[] b)throws IOException讲解&＃xff1a;将b.length个字节的byte数组写入当前输出流void flush() throws IOException讲解&＃xff1a; write是写到缓冲区中&＃xff0c;可以认为是内存中,当缓冲区满时系统会⾃自动将缓冲区的内容写入文件&＃xff0c;但是一般还有一部分有可能会留在内存这个缓冲区中, 所以需要调用flush空缓冲区数据。void close() throws IOException讲解&＃xff1a;关闭输入流并释放与该流关联的系统资源


• 常见子类
  • FileOutputStream
    • 抽象类OutputStream用来具体实现类的创建对象, 文件字节输出流, 对文件数据以字节的形式进行行输出的操作
    • 构造函数

//传入输出的文件地址public FileOutputStream(String name)//传入目标输出的文件对象public FileOutputStream(File file)//传入目标输出的文件对象, 是否可以追加内容public FileOutputStream(File file, boolean append)


eg&＃xff1a;

package domee.chapter10_3;import domee.chapter6_6.Vehicle;import java.io.*;public class Main {public static void main(String[] args) throws IOException {String dir &＃61; "C:\\Users\\123\\Desktop\\test";String name &＃61; "a.txt";String name0 &＃61; "b.txt";File file &＃61; new File(dir,name);InputStream inputStream &＃61; new FileInputStream(file);
// printlnFile(inputStream);
// System.out.println("&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;");OutputStream outputStream &＃61; new FileOutputStream(dir&＃43;File.separator&＃43;name0);//testWrite(inputStream,outputStream);testWriteBuf(inputStream,outputStream);}public static void read(InputStream inputStream)throws IOException{int readrulst &＃61; inputStream.read();System.out.println(readrulst);}public static void printlnFile(InputStream inputStream)throws IOException{byte[] buf &＃61; new byte[inputStream.available()];int lenget;while ((lenget &＃61; inputStream.read(buf)) !&＃61; -1){System.out.print(new String(buf,0,lenget));}inputStream.close();}//单个字节读取性能差效果不好&＃xff0c;中文会有乱码public static void testWrite(InputStream inputStream,OutputStream outputStream)throws IOException{int value &＃61; 0;while (value !&＃61; -1){value &＃61; inputStream.read();//System.out.print(value);outputStream.write(value);}inputStream.close();outputStream.close();}public static void testWriteBuf(InputStream inputStream,OutputStream outputStream)throws IOException{byte[] buf &＃61; new byte[1024];int length;while ((length &＃61; inputStream.read(buf)) !&＃61; -1){outputStream.write(buf,0,length);}inputStream.close();outputStream.close();}}