字节流FileInputStream

 1   /**
 2      * 字节流:字符流只能处理字符,对于图片等字节文件
 3      */
 4     @Test
 5     public void test() {
 6     //inputStream
 7         FileInputStream fileInputStream= null;
 8         try {
 9             File file=new File("hello.txt");
10             fileInputStream = new FileInputStream(file);
11             byte[]bytes=new byte[5];
12             int len;
13             while ((len=fileInputStream.read(bytes))!=-1){
14                 String str=new String(bytes,0,len);
15                 System.out.println(str);
16             }
17         } catch (IOException e) {
18             e.printStackTrace();
19         } finally {
20             try {
21                 fileInputStream.close();
22             } catch (IOException e) {
23                 e.printStackTrace();
24             }
25         }
26 
27 }
28 //jpg图像非文本文件,使用字节流可以进行复制
29 
30    @Test
31     public void test2(){
32        FileInputStream fileInputStream= null;
33        FileOutputStream fileOutputStream= null;
34        try {
35            File file=new File("123.jpg");
36            File file2=new File("1234.jpg");
37            fileInputStream = new FileInputStream(file);
38            fileOutputStream = new FileOutputStream(file2);
39            byte[]bytes=new byte[5];
40            int len;
41            while ((len=fileInputStream.read(bytes))!=-1){
42                fileOutputStream.write(bytes,0,len);
43            }
44        } catch (IOException e) {
45            e.printStackTrace();
46        } finally {
47            try {
48                fileInputStream.close();
49            } catch (IOException e) {
50                e.printStackTrace();
51            }
52            try {
53                fileOutputStream.close();
54            } catch (IOException e) {
55                e.printStackTrace();
56            }
57        }
58    }
59 }