Java 1.4.2 - 读取文件 [英] Java 1.4.2 - Reading Files

问题描述

我试图读取一个简单的文件，然后读取用户应该选择的文件。尽管如此，我一直在收到以下错误：

Readzilla.java:37：找不到符号

symbol：method FileReader（java.lang.String）
$ b $位置：类java.io.BufferedReader

line = read.FileReader（newDoc）;

这里是代码。

  import java.io. *; 
 
 public class Readzilla 
 {
 public static void main（String [] args）throws IOException 
 {
 String line; 
 BufferedReader读取; 
 // BufferedReaderread读取文件
 BufferedReader in; 
 // BufferedReaderin读取用户发送的输入
字符串循环; 
 //loop决定是否读取另一个文档
 
 in = new BufferedReader（new InputStreamReader（System.in））; 
 read = new BufferedReader（new FileReader（message.txt））; 
 line = read.readLine（）; 
 
 while（line！= null）
 {
 System.out.println（line）; 
 line = read.readLine（）; 
 
 
 //读取另一个文档
 System.out.println（你想读另一个文档吗？（是/否））; 
 loop = in.readLine（）; 
 loop = loop.toUpperCase（）; 
 
 if（loop ==Y）
 {
 do 
 {
 System.out.println（What file（.txt）would你喜欢阅读？）; 
 String newDoc = in.readLine（）; 
 // newDoc读取用户选择的文本文件
 line = read.FileReader（newDoc）; 
 // ^这行不断给出错误
 System.out.println（Reading ...）; 
 line = read.readLine（）; 
 
 while（line！= null）
 {
 System.out.println（line）; 
 line = read.readLine（）; 
 
 
 //读取另一个文档
 System.out.println（你想读另一个文档吗？（是/否））; 
 loop = in.readLine（）; 
} 
 while（loop ==Y）; 
} 
 else 
 {
 System.out.println（Closing Program ...）; 
 
 
 
 
 $ div class =h2_lin>解决方案

  line = read.FileReader（newDoc）; 
  

没有名为 FileReader 关于 BufferedReader ，这是编译器如何解释该行。 FileReader 本身就是一个类，它看起来像是在尝试打开一个新的文件来阅读。因此，您可能想要这样说：

  BufferedReader doc = new BufferedReader（new FileReader（newDoc））; 
  

之后，您需要替换

  line = read.readLine（）; 
  

与

  line = doc.readLine（）
  

因为这是您从文档中读取引用由 BufferedReader doc 。

另外，这里有一个问题（我看到两次） p>

  loop ==Y
  

在Java中， == 是 reference 仅 。在这里你绝对需要价值平等，所以说：

$ $ p $ $ $ $ $ $ $.equals（loop）;


这是一个常见的错误; == 作为参考平等只是一个糟糕的设计决定国际海事组织。

I am trying to read a simple file and then a file which the user is supposed to select. I keep on getting the following error though:

Readzilla.java:37: cannot find symbol

symbol : method FileReader(java.lang.String)

location: class java.io.BufferedReader

line = read.FileReader(newDoc);

Here is the code.

import java.io.*;

    public class Readzilla
    {
        public static void main(String[] args) throws IOException
        {
            String line;
            BufferedReader read;
            // BufferedReader "read" reads the file
            BufferedReader in;
            // BufferedReader "in" reads the input sent by the user  
            String loop;
            // "loop" decides whether another document should be read

            in = new BufferedReader(new InputStreamReader(System.in));
            read = new BufferedReader(new FileReader("message.txt"));
            line = read.readLine();

            while(line != null)
            {
                System.out.println(line);
                line = read.readLine();
            }

            // read another document
            System.out.println("Would you like to read another document? (Y/N)");
            loop = in.readLine();
            loop = loop.toUpperCase();

            if (loop == "Y")
            {
                do
                {
                    System.out.println("What file (.txt) would you like to read?");
                    String newDoc = in.readLine();
                    // newDoc reads a text file of the user's choosing
                    line = read.FileReader(newDoc);
                    //  ^ This line constantly gives errors
                    System.out.println("Reading...");
                    line = read.readLine();

                    while(line != null)
                    {
                        System.out.println(line);
                        line = read.readLine();
                    }

                    // read another document
                    System.out.println("Would you like to read another document? (Y/N)");
                    loop = in.readLine();
                }
                while (loop == "Y");    
            }
            else
            {
                System.out.println("Closing Program...");
            }
        }
    }

解决方案

Your problem is this line:

line = read.FileReader(newDoc);

There is no method named FileReader on the class BufferedReader, which is how the compiler is interpreting that line. FileReader is itself a class, and it looks like you're trying to open a new file for reading. Thus, you'd want to say something like:

BufferedReader doc = new BufferedReader(new FileReader(newDoc));

After that, you'd want to replace

line = read.readLine();

with

line = doc.readLine()

because that's how you'd read from the document referenced by the BufferedReader doc.

Additionally, you have a problem here (twice that I see):

loop == "Y"

In Java, == is reference equality only. You absolutely want value equality here so say:

"Y".equals(loop);

This is a common mistake; == as reference equality only was a poor design decision IMO.

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