I/O————字节流

public class StreamTest {

    public static void main(String[] args) {
        //准备一个文件文件内容是LOL，用来 字节输入流读取文件
        File file1 = new File("D:\\lolfilder\\lol.exe\\lol.txt");
        //准备一个空文件，用来字节输出流写入文件
        File file2 = new File("D:\\lolfilder\\lol.exe\\lol1.txt");
        
        try {
            FileInputStream fis = new FileInputStream(file1);
            FileOutputStream fos = new FileOutputStream(file2);
            byte[] all = new byte[(int) file1.length()];
            byte[] all2 = {65,97};
            fis.read(all);
            fos.write(all2);
            for(byte temp:all) {
                System.out.println(temp);
            }
            fis.close();
            fos.close();
        } catch (Exception e) {
            
            e.printStackTrace();
        }

    }

public class FileSplitTest {
    private static final int SPLIT_SIZE=100;

    public static void main(String[] args) {
         File file = new File("D:\\lolfilder\\lol.exe\\filesplitdemo.txt");
         splitFile(file, SPLIT_SIZE);

    }
    public static void splitFile(File file,int size) {
        try/*(FileInputStream fis = new FileInputStream(file);)
        可以将流定义在try中，当try，catch或finally结束后会自动关闭流，这是jdk7之后的技术
        
        */ {
            
            FileInputStream fis = new FileInputStream(file);
            byte []fisb = new byte[size];
            //fis.read(fisb);
            for(int i=1;fis.read(fisb, 0, size)>0;i++) {
                File subFile = new File(file.getAbsolutePath().replace(".txt",  "_" + i + ".txt"));
                FileOutputStream fos = new FileOutputStream(subFile);
                fos.write(fisb);
                fos.close();
            }
            fis.close();
            
            
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

public static void main(String[] args) {
         int i = 1;
         //建立输入文件
         File outFile = new File("D:\\lolfilder\\lol.exe\\mergedfile.txt");
         try {
             //建立输出流
         FileOutputStream fos = new FileOutputStream(outFile);
         //通过i依次读取
         while(new File("D:\\lolfilder\\lol.exe\\filesplitdemo_"+i+".txt").exists()) {
            
                File f = new File("D:\\lolfilder\\lol.exe\\filesplitdemo_"+i+".txt");
                FileInputStream fis = new FileInputStream(f);
                byte[] temp = new byte[fis.available()];
                fis.read(temp);
                fos.write(temp);
                i++;
                fis.close();
            } 
         fos.close();
         }catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
         }