File f =new File("~"); //创建源
InputStream is =new FileInputStream(f); //选择流
is.read() 读取单个数据，并使游标下移 //操作(读取)
is.close() //释放资源,输入流读取后必须释放资源

public class test{public static void main(String[]args) { //创建源 File f=new File("C:/Users/10853/eclipse-workspace/hell/src/hell/abc"); InputStream is =null;//提升is的作用域，避免在try中声明后，作用域 //只在try，finally中语句无法执行 //选择流 try { is =new FileInputStream(f); //操作(读取) int temp; while((temp=is.read())!=-1) //temp=is.read()表达式整体的值就是temp的值 { //is.read()会读取单个数据，当数据读取完毕时，返回-1 System.out.println((char)temp); } } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally { try { if(null!=is)//当is创建成功时才执行关闭 { is.close(); } } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } }} }