转换流

 1 package file;
 2 
 3 import java.io.BufferedReader;
 4 import java.io.File;
 5 import java.io.FileInputStream;
 6 import java.io.FileOutputStream;
 7 import java.io.IOException;
 8 import java.io.InputStream;
 9 import java.io.InputStreamReader;
10 import java.io.OutputStreamWriter;
11 
12 /*
13  转换流：
14  
15  输入字节流的转换流： 
16      InputStreamReader是字节流通向字符流的桥梁     
17  输出字节流的转换流： 
18      OutputStreamWriter是字节流通向字符流的桥梁     
19          
20   转换流的作用：
21      字节流---->字符流
22      
23  
24  */
25 public class Demo12 {
26     public static void main(String[] args) throws IOException {
27 //        readTest();
28 //        writeTest();
29 //        writeTest2();
30         readTest2();
31     }
32     
33     //使用输入字节流的转换流 指定码表读取数据
34     public static void readTest2() throws IOException {
35         File file = new File("F:\a.txt");
36         //建立数据输入通道
37         FileInputStream fileInputStream = new FileInputStream(file);
38         //把输入字节流转换 并且指定码表
39         InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream,"utf-8");
40         char[] buf = new char[1024];
41         int length = 0;
42         while((length = inputStreamReader.read(buf))!=-1)  {
43             System.out.println(new String(buf,0,length));
44         }
45         inputStreamReader.close();
46     }
47     
48     
49     //使用输出字节流的转换流 指定码表写出数据
50     public static void writeTest2() throws IOException {
51         File file = new File("F:\a.txt");
52         //建立数据输出通道
53         FileOutputStream fileOutputStream = new FileOutputStream(file);
54         //把输出字节流转换成字符流并且指定码表
55         OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream, "utf-8");
56         outputStreamWriter.write("ab哈哈哈");
57         //关闭资源
58         outputStreamWriter.close();
59         
60     }
61     
62     // 输出字节流的转换流： 
63     public static void writeTest() throws IOException {
64         File file = new File("F:\a.txt");
65         FileOutputStream fileOutputStream = new FileOutputStream(file);
66         //输出字节流转换成字符流
67         OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream);
68         
69         outputStreamWriter.write("hello大家好");
70         outputStreamWriter.close();
71     }
72     
73     
74     // 输入字节流的转换流： 字节流---->字符流
75     public static void readTest() throws IOException {
76         InputStream in = System.in;
77         //需要把字节流转换成字符流
78         InputStreamReader inputStreamReader = new InputStreamReader(in);
79         //使用字符流的缓冲类
80         BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
81         
82         String line = null;
83         while((line = bufferedReader.readLine())!= null) {
84             System.out.println("内容：" + line);
85         }
86         bufferedReader.close();
87     }
88 }