1
import java.io.File; import java.io.FileInputStream; /** * 读取一个字符 */ public class MyReadChar { public static void main(String[] args) { try { File f = new File("D:\labs\test.txt"); FileInputStream fis = new FileInputStream(f); System.out.println((char)fis.read()); } catch (Exception e) { } } }
2
import java.io.File; import java.io.FileInputStream; public class MyReadFile { public static void main(String[] args) { try { File f = new File("D:\labs\test.txt"); FileInputStream fis = new FileInputStream(f); int length = fis.available(); for (int i = 0; i <length; ++i) { System.out.print((char)fis.read()); } } catch (Exception e) { } } }
3
import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; public class MyCopyFile { public static void main(String[] args) { try { File in = new File("D:\labs\test.txt"); File out = new File("D:\labs\another_test.txt"); FileInputStream fis = new FileInputStream(in); FileOutputStream fos = new FileOutputStream(out); int length = fis.available(); for (int i = 0; i < length; ++i) { fos.write(fis.read()); } } catch (Exception e) { } } }
4
import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; public class MyCopyBigFile { public static void main(String[] args) { try { File in = new File("D:\labs\test.txt"); File out = new File("D:\labs\another_test.txt"); FileInputStream fis = new FileInputStream(in); FileOutputStream fos = new FileOutputStream(out); byte[] tmp = new byte[8192]; // 处理大部分内容 int length = fis.available()/8192; for (int i = 0; i < length; ++i) { fis.read(tmp); fos.write(tmp); } int size = fis.read(tmp); fos.write(tmp, 0, size); } catch (Exception e) { } } }
5
import java.io.File; import java.io.FileOutputStream; public class MyKey { public static void main(String[] args) { try { File f = new File("D:\labs\key.key"); FileOutputStream fos = new FileOutputStream(f); for (int i = 0; i < 128; ++i) { fos.write((int)(Math.random()*128)); } } catch (Exception e) { } } }
6
import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; public class MyEncryp { public static void main(String[] args) { try { int key[] = new int[128]; File keyFile = new File("D:\labs\key.key"); FileInputStream keyFis = new FileInputStream(keyFile); for (int i = 0; i < 128; ++i) { key[i] = keyFis.read(); } File in = new File("D:\labs\test.txt"); File out = new File("D:\labs\another_test.txt"); FileInputStream fis = new FileInputStream(in); FileOutputStream fos = new FileOutputStream(out); int length = fis.available(); for (int i = 0; i < length; ++i) { fos.write(fis.read() + key[i%128]); } } catch (Exception e) {} } }