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 }