从文件中读取并在另一个文件中写入部分

Question

我必须从文本文件中读取并格式化输入。我刚开始从java读取文件，我不知道如何处理我在这里读到的一些部分：http://pastebin.com/D0paWtAd

我必须在另一个文件中写入以下输出: Average，Joe,44,31,18,12,9,10

我只想把文件中的所有内容打印出来输出。我需要帮助才能获得所需的输出并将其打印到屏幕上。任何帮助都是非常感谢的。

这是我写到现在的：

public class FileParsing {
public static String

read(String filename) throws IOException {
BufferedReader in = new BufferedReader(new FileReader("C:\\Users\\Bogdi\\Desktop\\example.txt"));

String s;
StringBuilder sb = new StringBuilder();
while((s = in.readLine())!= null)   sb.append(s + "\n");

in.close();

return sb.toString();
}

Answer 1

如果您的目标是在另一个文件中执行指定的输出(您不需要在处理之前先在StringBuilder中获取文件的内容)，则可以将处理过的数据直接附加到StringBuilder中，然后将结果写入文件中。下面是一个适用于给定文件的示例，但是如果将来键发生变化，您可能不得不修改它：

以下方法将正确处理文件中的数据

public static String read(String filename) throws IOException {
    BufferedReader in = new BufferedReader(new FileReader(filename));

    String s;
    StringBuilder sb = new StringBuilder();
    while((s = in.readLine())!= null) {
        String[] split1 = s.split("=");

        if (split1[0].equals("name")) {

            StringTokenizer tokenizer = new StringTokenizer(split1[1]);
            sb.append(tokenizer.nextToken());
            sb.append(",");

            sb.append(tokenizer.nextToken());
            sb.append(",");


        } else if (split1[0].equals("index")) {

            sb.append(split1[1] + ",");

        } else if (split1[0].equals("FBid")) {
            sb.append(split1[1]);

        } else {

            StringTokenizer tokenizer = new StringTokenizer(split1[1]);
            String wasted = tokenizer.nextToken();

            sb.append(tokenizer.nextToken() + ",");

        }

    }

    in.close();

    return sb.toString();
}

下一个方法将将任何字符串读入文件。

public static void writeStringToFile(String string, String  filePath) throws IOException {

    BufferedWriter writer = new BufferedWriter(
            new FileWriter(
                    new File(filePath)
                    )
            );

    writer.write(string);

    writer.newLine();
    writer.flush();
    writer.close();

}

下面是一个简单的测试(File1.txt包含您在粘贴bin上共享的文件中的数据，我将它们写入另一个文件中)

public static void main(String[] args) throws Exception {

    String datas = read("C:\\Tests\\File1.txt");
    System.out.println(datas);

    writeStringToFile(datas, "C:\\Tests\\FileOuput.txt" );


}

它将产生您所期望的确切输出。

编辑 @idk，显然有一个异常执行我的示例，而它对我很好。这只能意味着在数据级别有一个错误。下面是我使用的数据示例(我相信我准确地复制了您共享的数据)

​

​

其结果是：

​

​

Answer 2

很高兴知道您正在使用"StringBuilder“组件，而不是连接您的字符串值，方法是:)。

除了了解如何处理文件外，您还需要一些逻辑来获得预期的结果。这里我带了一种方法，可以帮助你，不是完美的，但可以告诉你如何面对这个问题。

//Reference to your file
    String myFilePath = "c:/dev/myFile.txt";
    File myFile = new File(myFilePath);

    //Create a buffered reader, which is a good start
    BufferedReader breader = new BufferedReader(new FileReader(myFile));
    //Define this variable called line that will evaluate each line of our file
    String line = null;
    //I will use a StringBuilder to append the information I need
    StringBuilder appender = new StringBuilder();

    while ((line = breader.readLine()) != null) {
        //First, I will obtain the characters after "equals" sign
        String afterEquals = line.substring(line.indexOf("=") + 1, line.length());

        //Then, if it contains digits...
        if (afterEquals.matches(".*\\d+.*")) {
            //I will just get the digits from the line
            afterEquals = afterEquals.replaceAll("\\D+","");
        }

        //Finally, append the contents
        appender.append(afterEquals);
        appender.append(",");//This is the comma you want to include
    }

    //I will delete the last comma
    appender.deleteCharAt(appender.length() - 1);

    //Close the reader...
    breader.close();

    //Then create a process to write the content
    BufferedWriter myWriter = new BufferedWriter(new FileWriter(new File("myResultFile.txt")));
    //Write the full contents I get from my appender :)
    myWriter.write(appender.toString());
    //Close the writer
    myWriter.close();
}

希望这能帮到你。编码愉快！