java - 我正在用正则表达式编写 java 程序，我想从文件中读写

Question

假设输入文件（book.txt）包含句子，例如：

book 'learning java' for doctor  ahmed mohamed.
the best title is:How to program for simth sahg.

我想从文件（book.txt）中读取每个句子，而不是从键盘输入，并将文件中的每个句子与 3 种模式匹配：

 String p1 = "(book|\\)|\\:) (.*) for( doctor| author|) (.*)";
String p2 = "regex two";
String p3 = "regex three";

// matcher for each of the patterns .
Matcher m1=Pattern.compile(p1).matcher(inputtext);
Matcher m2=Pattern.compile(p2).matcher(inputtext);
Matcher p3=Pattern.compile(p3).matcher(inputtext);

如果句子匹配任何模式，则将提取并写入新文件（bookout.txt）中的[作者，标题]

或不匹配任何模式写“句子”不匹配（bookout.txt）

鳕鱼是

    String p1 = "(book|\\)|\\:) (.*) for( doctor| author|) (.*)";
    String p2 = "regex two";
    String p3 = "regex three";
String inputtext = null;
            // matcher for each of the patterns .
            Matcher m1=Pattern.compile(p1).matcher(inputtext);
            Matcher m2=Pattern.compile(p2).matcher(inputtext);
            Matcher m3=Pattern.compile(p3).matcher(inputtext);


            try {
                BufferedWriter bw = new BufferedWriter(new FileWriter("bookout.txt",true));

            BufferedReader br = new BufferedReader(new FileReader(new File("book.txt") ));
                        inputtext= br.readLine();
                    while ((inputtext=br.readLine())!= null)
                            System.out.println(inputtext);

            String author=null;
        String title = null;

        if (m1.find()) {                //if input matches p1
            title = m1.group(2).trim();
            author = m1.group(4).trim();
        } else if (m2.find()) {           //else if input matches p2
            title = m2.group(1).trim();
            author = m2.group(3).trim();
        } else if (m3.find()) {            //else if input matches p3
            author = m3.group(2).trim();
            title = m3.group(4).trim();
        }

        if (author ==null || title == null) {   //If no matches set the author and title strings...
            bw.write("inputNot match");    //There's no match
        } else {                                //Otherwise...

            bw.write("Author : " + author);
            bw.write("Title : " + title);
            bw.close();

        }

                    } catch (Exception e) {

                        e.printStackTrace();

                    }

请帮助我，如何在控制台上显示输出而不是显示将写入另一个文件（bookout.txt）

Answer 1

使用 yourBufferedWriter将输出写入文件。例如：

BufferedWriter bw = new BufferedWriter(new FileWriter("bookout.txt",true));

// write to the file
bw.write("Author : " + author);

// close the writer when you have finished writing everything
bw.close();

Answer 2

代替

System.out.println("Author : " + author);
    System.out.println("Title : " + title);

利用

bw.write(inputtext )