讀取文本文件:

 1 private static void ioDemo1() {
 2     try {
 3         FileReader fileReader = new FileReader("C:\\Users\\yan\\Desktop\\編碼規範 (2).txt");
 4         int aa;
 5         aa = fileReader.read();
 6         while (aa!=-1) {//轉換為char類型，否則是一堆數字
 7             System.out.print((char)aa);
 8             aa = fileReader.read();
 
 9         }
10         fileReader.close();
11     } catch (FileNotFoundException e) {
12         e.printStackTrace();
13     } catch (IOException e) {
14         e.printStackTrace();
15     }
16 }

復制二進制文件:

 1 private static void ioDemo2() {
 2     try {
 3         FileInputStream fr = new FileInputStream("D:/test.xlsx");//
 
不能使用FileReader（字符流）
 4         FileOutputStream fw = new FileOutputStream("D:/test1.xlsx");
 5         int read = fr.read();
 6         while (read!=-1) {
 7             fw.write(read);
 8             read=fr.read();
 9         }
10         fw.flush();//杯子中沒有飲料不代表飲料已喝完，此方法就是清空吸管中的飲料
11         fw.close();
 
12         fr.close();
13     } catch (FileNotFoundException e) {
14         e.printStackTrace();
15     } catch (IOException e) {
16         e.printStackTrace();
17     }
18 }

使用緩沖流復制二進制文件:

 1 private static void ioDemo3() {
 2     try {
 3         BufferedInputStream bis = new BufferedInputStream(new FileInputStream("D:/test.xlsx"));
 4         BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("C:\\Users\\yan\\Desktop\\test.xlsx"));
 5         byte[] buffer = new byte[2048];
 6         int read = bis.read(buffer);
 7         while(read!=-1)
 8         {
 9             bos.write(buffer, 0, read);
10             read = bis.read(buffer);
11         }
12         bos.flush();
13         bos.close();
14         bis.close();
15     } catch (FileNotFoundException e) {
16         e.printStackTrace();
17     } catch (IOException e) {
18         e.printStackTrace();
19     }
20 }

數據流傳遞數據:

 1     private static void ioDemo4() {
 2         try {
 3 
 4             ByteArrayOutputStream baos = new ByteArrayOutputStream();
 5             DataOutputStream dos = new DataOutputStream(baos);
 6             long src = 1234454544;
 7             dos.writeLong(src);
 8 
 9             byte[] bytes = baos.toByteArray();
10             ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
11             DataInputStream dis = new DataInputStream(bais);
12             long recieve;
13             recieve = dis.readLong();
14 
15             System.out.println("recieve:" + recieve);
16 
17         } catch (IOException e) {
18             e.printStackTrace();
19         }
20     }

PrintStream:

參考

ObjectStream：

 1     private static void ioDemo5() {
 2         ObjectOutputStream oos = null;
 3         ObjectInputStream ois = null;
 4         Student s = new Student("悟空", 007, 95.5f);
 5         Student s1 = null;
 6 
 7         try {
 8             FileOutputStream fos = new FileOutputStream("C:\\Users\\yan\\Desktop/ccc.txt");
 9             oos = new ObjectOutputStream(fos);
10             oos.writeObject(s);
11 
12             ois = new ObjectInputStream(new FileInputStream("C:\\Users\\yan\\Desktop/ccc.txt"));
13             s1 = (Student) ois.readObject();
14 
15             System.out.println("姓名：" + s1.getName());
16             System.out.println("學號：" + s1.getId());
17             System.out.println("成績：" + s1.getScore());
18             fos.close();
19         } catch (Exception e) {
20             e.printStackTrace();
21         } finally {
22             try {
23                 oos.close();
24                 ois.close();
25                 System.exit(-1);
26             } catch (Exception e) {
27                 System.exit(-1);
28             }
29         }
30     }
31 //實現Serializable的作用是可以將對象保存在文件中用於傳輸
32 class Student implements Serializable {
33     private static final long serialVersionUID = -111977186014986048L;
34     private String name;
35     private int id;
36     private transient float score;//transient意思是轉瞬即逝，起的作用是反序列化
37 
38     public Student(String name, int id, float score) {
39         super();
40         this.name = name;
41         this.id = id;
42         this.score = score;
43     }
44 
45     public String getName() {
46         return name;
47     }
48 
49     public void setName(String name) {
50         this.name = name;
51     }
52 
53     public int getId() {
54         return id;
55     }
56 
57     public void setId(int id) {
58         this.id = id;
59     }
60 
61     public float getScore() {
62         return score;
63     }
64 
65     public void setScore(float score) {
66         this.score = score;
67     }
68 }

Java基礎--常用IO流使用實例