Java 1.4.2-读取文件

Question

我正在尝试读取一个简单的文件，然后再读取一个用户应该选择的文件。我仍然不断遇到以下错误：

Readzilla.java:37：找不到符号

symbol：方法FileReader（java.lang.String）

位置：类java.io.BufferedReader

行= read.FileReader（newDoc）;

这是代码。

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...");
            }
        }
    }

Answer 1

您的问题是这一行：

line = read.FileReader(newDoc);

FileReader类上没有命名方法BufferedReader，这是编译器解释该行的方式。FileReader本身就是一个类，看起来您正在尝试打开一个新文件进行读取。因此，您想说些类似的话：

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

之后，您要替换

line = read.readLine();

与

line = doc.readLine()

因为这是您从中引用的文档中读取的方式BufferedReader doc。

此外，您在这里遇到问题（我发现有两次）：

loop == "Y"

在Java中，==是 参考 平等 只 。您绝对希望在这里实现价值平等，因此请说：

"Y".equals(loop);

这是一个常见的错误；==作为参考平等，IMO的设计决策很差。