Question

下面的代码应该读取文件MainFile.txt中的每一行，检查每行是否包含来自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编写一个新文件。输出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

令牌需要修剪，即当扫描仪读取令牌时应删除逗号后的空格：

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 + ", ");
    }

}

您也可以通过在评论中更新Marko Topolnik建议的Scanner分隔符模式来完成此操作。

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

\\s*表示零个或多个空白字符。

如果在字符串集中找到，则替换字符串标记

1 个答案: