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我正在尝试读取文件内容并删除一些指定的字符串，但我仍然没有成功。我也试过这个链接

但它不起作用，我也尝试过忽略大小写，在这种情况下我的整个文件都被删除了。:(

我自己的代码就像

BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(file), charset));
        PrintWriter writer = new PrintWriter(new OutputStreamWriter(new FileOutputStream(tempfile), charset));  BufferedWriter bw = new BufferedWriter(writer);

        while((currentLine = reader.readLine()) != null)
        {
            //System.out.println(currentLine);

            if (currentLine.equals(del))
            currentLine = currentLine.replace(del, "");
            writer.write(currentLine);

        }
      tempfile.renameTo(file);
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5 回答 5

0

您的逻辑将仅在整行匹配时删除字符串，如果您想在每行中匹配字符串的一部分，请尝试使用字符串类中可用的匹配（或）子字符串方法

于 2013-09-09T07:44:14.107 回答
0

您是否遇到任何异常或只是新文件的所有内容与原始文件相同？

您应该关闭写入流，以便将其内容刷新到物理文件，然后可以尝试检查文件。

于 2013-09-09T07:45:06.410 回答
0

currentLine.equals(del)你的意思是currentLine.matches(del)

currentLine.equals(del)匹配整行，同时currentLine.matches(del)匹配 currentLine 的子字符串。

于 2013-09-09T07:45:58.900 回答
0

你可以这样做

    BufferedReader br = new BufferedReader(new FileReader("D:\\test.txt"));
    List<String> lines=new ArrayList<>();
    String currentLine = new String();
    while ((currentLine = br.readLine()) != null) {
        if (currentLine.contains("hi")) {
            lines.add(currentLine.replace("hi", ""));
        }else {
            lines.add(currentLine);
        }
    }
    BufferedWriter bw = new BufferedWriter(new FileWriter("D:\\test.txt"));
    for (String i:lines){
       bw.write(i);
       bw.newLine();
    }
    bw.close();

这是我的输入。

   hi how are you?
   I am fine.
   again hi hi.

输出

how are you?
I am fine.
again  .
于 2013-09-09T08:37:12.107 回答
0

您可以保留大部分原始代码并避免将整个文件存储在列表中（如果您的文件很大，这可能会很糟糕）。这是一个你可以玩的单机：

import java.io.*;

public class StringRepl {
    public void doReplace(String oldFileName, String newFileName) {
        File oldFile = new File(oldFileName);
        File tempFile = new File(newFileName);

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(oldFile), "utf-8"));

            PrintWriter writer = new PrintWriter(new OutputStreamWriter(new FileOutputStream(tempFile), "utf-8"));
            BufferedWriter bw = new BufferedWriter(writer);
            String currentLine;
            String del = "hi";
            while((currentLine = reader.readLine()) != null)
            {
                //System.out.println(currentLine);

                if (currentLine.contains(del))
                    currentLine = currentLine.replace(del, "");
                bw.write(currentLine);
                bw.newLine();

            }
            bw.close();
            reader.close();
            writer.close();
            //tempFile.renameTo(oldFile);
        } catch (FileNotFoundException fnfe) {
            System.out.print("No file found: " + oldFileName);
        } catch (UnsupportedEncodingException uee) {
            System.out.print("'utf-8' not supported");
        } catch (IOException ioe) {
            System.out.print("Error using file!");
            ioe.printStackTrace();
        }
    }

    public static void main(String[] args) {
        StringRepl sr = new StringRepl();
        sr.doReplace("o.txt","n.txt");
    }
}

编译并运行：

javac StringRepl.java
java StringRepl

o.txt：

hi how are you?
I am fine.
again hi hi.

n.txt：

 how are you?
I am fine.
again  .
于 2013-09-09T09:20:27.887 回答