FileInputstream和FileOutpunstream
package Z3_3; import java.io.File; import java.io.IOException; import java.io.FileInputStream; import java.io.FileOutputStream; public class Zijie { public static void main(String[] args)throws Exception{ File file=new File("src/5714.txt"); FileInputStream fis=null; try { fis=new FileInputStream(file); int data; while((data=fis.read())!=-1){ System.out.print((char)data); } System.out.println("\n还有未读字节:"+fis.available()); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ fis.close(); } System.out.println("写入mijia"); FileOutputStream fiss=null; try { fiss=new FileOutputStream(file,true); String str="\nmijia"; byte[]linshi=str.getBytes();//将字符串转换成字节数组 fiss.write(linshi,0,3);//传入参数,从第off,到len字符 } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ System.err.println("close"); fiss.close(); } try { int data; fis=new FileInputStream(file); while((data=fis.read())!=-1){ System.out.print((char)data); } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ System.err.println("\nclose"); fiss.close(); } } }