基本java代码出错

Question

这是一些基本的java代码:

package javaapplication32;

import java.io.*;

public class JavaApplication32 {
    public static void main(String[] args)throws Exception {
        try{
            out = new DataOutputStream(new BufferedOutputStream(new FileOutputStream("dec.dat")));
            in = new DataInputStream(new BufferedInputStream(new FileInputStream("enc.dat")));

            String enc=in.readUTF();
            System.out.println(enc);
        }catch(EOFException e){
        }
    }   
}

我收到错误,它找不到符号'in'或'out'

Answer 1

你应该先申报它们.

public static void main(String[] args)throws Exception {
    DataOutputStream out = null; 
    DataInputStream in = null;
    try{
        out = new DataOutputStream(new BufferedOutputStream(new FileOutputStream("dec.dat")));
        in = new DataInputStream(new BufferedInputStream(new FileInputStream("enc.dat")));

        String enc=in.readUTF();
        System.out.println(enc);
    }catch(EOFException e){
    }
}   

Answer 2

为了定义变量,您必须为它们提供类型,例如:

OutpustStream out = new DataOutputStream(new BufferedOutputStream(new FileOutputStream("dec.dat")));
InputStream in = new DataInputStream(new BufferedInputStream(new FileInputStream("enc.dat")));