如果在字符串集合中找到，则替换字符串标记

Question

下面的代码应该从文件 MainFile.txt 中读取每一行，检查每一行是否包含来自 Set 的标记。如果确实包含，请将其替换为“xxx”字符串。然后使用 BufferedWriter 写入一个新文件。 输出的 ConvFile.txt 与输入完全相同。

MainFile.txt：

car, 18, train, 19, bus,
laptop, 20, tablet, 21, computer,
swim, 22, bike, 23, run,



public class ReplaceWords {

Set<String> wordToReplace;

public ReplaceWords(){
    this.wordToReplace = new HashSet<>();
    this.wordToReplace.add("18");
    this.wordToReplace.add("19");
    this.wordToReplace.add("20");
    this.wordToReplace.add("21");
    this.wordToReplace.add("22");
    this.wordToReplace.add("23");
}

public void redactFile(){
    String inPathname = "E:\\SkyDrive\\Java\\Coding\\FileChgOne\\MainFile.txt";
    String outPathname = "E:\\SkyDrive\\Java\\Coding\\FileChgOne\\ConvFile.txt";
    File inFile = new File(inPathname);
    File outFile = new File(outPathname);

    Scanner bufferedScanner = null;
    BufferedWriter bufferedFileWriter = null;



    try {
        Scanner lineScanner;
        String currentLine;

        bufferedScanner = new Scanner(new BufferedReader(new FileReader(inFile)));
        bufferedFileWriter = new BufferedWriter(new FileWriter(outFile));

        while(bufferedScanner.hasNextLine()){
            currentLine = bufferedScanner.nextLine();
            lineScanner = new Scanner(currentLine);
            lineScanner.useDelimiter(",");

            while(lineScanner.hasNext()){
                String currentToken = lineScanner.next();
                if (this.wordToReplace.contains(currentToken)){
                    bufferedFileWriter.write("xxx, ");
                }
                else {
                    bufferedFileWriter.write(currentToken + ", ");
                }

            } 
            bufferedFileWriter.newLine();
        }

    }
    catch (Exception en){
        System.out.println("error: " + en);
    }

    finally {
        try {
            bufferedScanner.close();
            bufferedFileWriter.close();
        }
        catch (Exception en) {
            System.out.println(en);
        }
    } 
} 
}

输出ConvFile.txt：

car,  18,  train,  19,  bus, 
laptop,  20,  tablet,  21,  computer, 
swim,  22,  bike,  23,  run, 

Answer 1

令牌需要被修剪，即当扫描仪读取令牌时，逗号后的空格应该被删除：

while(lineScanner.hasNext()){
    String currentToken = lineScanner.next();
    currentToken = currentToken.trim();  // line to add
    if (this.wordToReplace.contains(currentToken)){
        bufferedFileWriter.write("xxx, ");
    }
    else {
        bufferedFileWriter.write(currentToken + ", ");
    }

}

您也可以按照 Marko Topolnik 在 cmets 中的建议更新 Scanner 的分隔符模式。

lineScanner = new Scanner(currentLine);
lineScanner.useDelimiter("\\s*,\\s*");

\\s* 表示零个或多个空白字符。