有人可以帮助我获得缓冲的阅读器以使用Java吗？ [英] Can someone help me to get buffered reader to work in Java?

问题描述

在这里，我正在尝试阅读包含单词和相应缩写的文档。例如。

Here I am trying to read a document that has words and corresponding abbreviations. E.g.

one,1
two,2
easy,ez

每行都是分隔的，单词和缩写之间用逗号分隔。

Each line is separated, and the words are separated from the abbreviations with a comma.

当我希望缓冲的阅读器继续使用

When I want the buffered reader to keep reading lines using

while ((line = br.readLine()) != null)

不会。它只会读取第一行。这意味着它将显示1的缩写，即1。但是，如果我输入另一个值，说2，则会收到此错误消息。

it won't. It will only read the first line. This means it will display the abbreviation for one, which is 1. But if I input another value say two, I get this error message.

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 5
    at java.lang.String.charAt(String.java:658)
    at shortener.NewClass.Short(NewClass.java:41)
    at shortener.NewClass.main(NewClass.java:26)
Java Result: 

---

这是代码

---

here's the code

public static String Short(String input) {

    try {
        FileReader fr = new FileReader("abbreviations.txt");
        BufferedReader br = new BufferedReader(fr);

        String line;
        while ((line = br.readLine()) != null) {

            for(int i = 0; i <= line.length(); i++) {
                if(line.charAt(i) == ','){
                    String strOrig = line.substring(0, i);
                    if(strOrig.equals(input)) {
                        String strAbv = line.substring(line.length()-1);
                        return strAbv;
                        }
                    }                
                }
            }   
        br.close();
        } catch (IOException e) {
        out.println("File Not found");
    }
    return null;
}

推荐答案

您已创建了条件表达式在 for 循环中，因为 i小于或等于line.length（）。错了。 i 不应等于行的长度。更改此

You have made the conditional expression in for loop as i lesser than or equal to line.length(). That's wrong.i shouldn't be equal to the length of the line. Change this

for(int i = 0; i <= line.length(); i++)

至

for(int i = 0; i < line.length(); i++)

使 i 等于行的长度。索引从 0 开始。因此，有效索引应为 0 到 length-1

you can't make i equal to the length of line. The index starts from 0. so, the valid indexes would be from 0 to length-1

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