1 import java.io.BufferedInputStream;
2 import java.io.BufferedOutputStream;
3 import java.io.DataInputStream;
4 import java.io.DataOutputStream;
5 import java.io.FileInputStream;
6 import java.io.FileOutputStream;
7 import java.io.IOException;
8 import java.io.PrintWriter;
9
10 public class TextCode {
11 public static void main(String[] args) throws IOException {
12
13 DataOutputStream output = new DataOutputStream(
14 new BufferedOutputStream(new FileOutputStream("data.dat")));
15 output.writeChar('a');
16 output.writeInt(5);//int型32位
17 output.writeInt(16);/*十六进制显示：00 61 00 00 00 05 00 00 00 10*/
18 output.flush();//当缓冲区填满或当流被清空时，数据就被写出。
19 DataInputStream input = new DataInputStream(
20 new BufferedInputStream(new FileInputStream("data.dat")));
21 System.out.println(input.readChar());
22 System.out.println(input.readInt());
23 System.out.println(input.readInt());
24 output.close();
25 input.close();
26 PrintWriter out = new PrintWriter("text.txt");
27 out.println("你好");
28 out.println("Hello");
29 out.print(10);/*十六进制显示：
30 C4 E3 BA C3 0D OA 48 65 6C 6C 6F 0D 0A 31 30*/
31 out.close();//如果没有调用该方法，数据就不能正确地保存在文件中
32 }
33 }

FileInputStream和FileOutputStream类：是为了从/向文件读取/写入字节。

FilterInputStream类和FilterOutputStream类：过滤器数据流。

DataInputStream类（从数据流读取字节，并且把它们转换为正确的基本类型或字符串）和DataOutputStream类（将基本类型的值或字符串转换成字节，并且将字节输出到数据流）

• +readByte():byte    +writeByte(v: int):void
• +readDouble():double    +writeDouble(v: double):void
• +writeChar(c: char): void 向输出流写入一个字符（由两个字节组成）
• +writeChars(s: String): void

BufferedInputStream类和BufferedOutputStream类为存储字节在流中添加一个缓冲区，以提高处理效率。

• BufferedInputStream(int: InputStream)
• BufferedOutputStream(filename:String, bufferSize: int)

ObjectInputStream类和ObjectOutputStream类：对象的输入输出。

• ObjectInputStream(in: InputStream)

• ObjectOutputStream(out: OutputStream)

  1 import java.io.BufferedInputStream;
  2 import java.io.BufferedReader;
  3 import java.io.DataInputStream;
  4 import java.io.File;
  5 import java.io.FileInputStream;
  6 import java.io.FileNotFoundException;
  7 import java.io.FileReader;
  8 import java.io.IOException;
  9 import java.io.InputStreamReader;
  10 import java.util.Scanner;
  11
  12
  13 public class Test {
  14 public static void main(String[] args) throws IOException {
  15 BufferedReader in;
  16 try {
  17 //FileReader会抛出异常
  18 in = new BufferedReader(new FileReader("text.txt"));
  19 System.out.println(in.readLine());
  20 in.close();
  21 } catch (IOException e) {
  22 }
  23 try {
  24 Scanner input = new Scanner(new File("text.txt"));
  25 System.out.println(input.nextLine());
  26 input.close();
  27 } catch (FileNotFoundException e) {
  28 }
  29 /*BufferedReader从字符输入流中读取文本，缓冲各个字符，从而实现字符、数组和行的高效读取。*/
  30 /*InputStreamReader类将包含字节（用某种字符编码方式表示的字符）的输入流转换为可以产生Unicode字符的读入器*/
  31 BufferedReader inp = new BufferedReader(new InputStreamReader(System.in));//字符的读取
  32 Scanner input1 = new Scanner(System.in);//从键盘输入
  33 try{
  34 FileInputStream fileInput = new FileInputStream("text.txt");//只能读入字节和字节数组
  35 /*默认不使用缓冲区*/
  36 DataInputStream din = new DataInputStream(fileInput);//可以读取数据类型Byte,Int,Char,Double…
  37 /*嵌套过滤器来添加多重功能*/
  38 DataInputStream dInput = new DataInputStream(
  39 new BufferedInputStream(new FileInputStream("text1.txt")));
  40 System.out.println(dInput.readChar());
  41
  42 }
  43 catch(FileNotFoundException e){
  44 }
  45 try {
  46 FileReader fileReader = new FileReader("tetx.txt");
  47 } catch (Exception e) {
  48 }
  49 }
  50
  51 }