1 import java.io.File; 2 import java.io.FileInputStream; 3 import java.io.FileNotFoundException; 4 import java.io.IOException; 5  6 public class Demo4 { 7  8     public static void main(String[] args) { 9         // TODO Auto-generated method stub10        11         getFile();12     }13     14     public static void getFile() {15         16         //1.找到目标文件17         File file = new File("D:\\a.txt");18         //2.建立通道19         FileInputStream inputStream = null;20         try {21             inputStream = new FileInputStream(file);22             byte[] b = new byte[1024];23             try {24                 int count = inputStream.read(b);25                 System.out.println(new String(b,0,count));26             } catch (IOException e) {27                 28                 System.out.println("硬盘损坏了,请修理");29                 30                 throw new RuntimeException(e);31             }32             33             34         } catch (FileNotFoundException e) {35             36             System.out.println("文件不存在");37             //提示用户有错误要修改38             //让后面的代码定制运行39             //System.exit(0); 不太好，一般是不随意推出虚拟机。40             throw new RuntimeException(e);  //创建一个运行时异常41         }finally {42             43             try {44                 inputStream.close();45             } catch (IOException e) {46                 System.out.println("关闭失败");47                 throw new RuntimeException(e);48             }49         }55     }57 }