我的String和StringBuilder在控制台中未显示输出

Question

我正在从一个PDF页面解析文本数据。我能够应用正则表达式（被称为stackoverflow解决方案之一）并仅获得我正在寻找的文本。问题是，在每次间歇迭代时将解析的字符串附加到StringBuilder会在SOPing时在控制台中显示数据，但不会显示最终值（该特定页面的整个文本数据）。我尝试了以下操作：

1）转到窗口>首选项>运行/调试>控制台取消选中“限制控制台输出”

2）尝试在文本文件中写入相同的字符串。

3）检查了显示3746的字符串的长度（这意味着其中有很多数据）。

package com.PDFReaderApp2;

private static ReentrantLock counterLock = new ReentrantLock(true);
private static Pattern PARAGRAPH = Pattern.compile("\\s*^\\s*$\\s*", Pattern.MULTILINE);
private static Pattern MULTISPACE = Pattern.compile("\\s+");
private static boolean flag = false;
private static BufferedWriter writer = null;

public static StringBuilder processString2(String args) {
    StringBuilder builder = new StringBuilder();
    String x = args;
    x = compactLines(x);
    Matcher m = Pattern.compile("\\((.*?)\\)").matcher(x);
    while (m.find()) {
        x = m.group(1);
        builder = builder.append(x);
        x = builder.toString();
        // x= x.replaceAll(System.lineSeparator(), " ");
        System.out.println("-->>  " + x);
    }

    System.out.println("is x empty?: " + x.length());
    x = builder.toString();

    return builder;
}

public static String compactLines(String source) {
    return Stream.of(PARAGRAPH.split(source)).map(para -> MULTISPACE.matcher(para).replaceAll(" "))
            .collect(Collectors.joining("\n"));
}

public void readThisPage(int pageNum) throws IOException {
    writer = new BufferedWriter(new FileWriter("C:\\Users\\bhard\\Desktop\\output.txt", true));
    InputStream inputStream = document.getPages().get(pageNum).getContents();
    String text = new String();
    text = IOUtils.toString(inputStream, StandardCharsets.UTF_8.name());
    System.out.println(text);
    StringBuilder mofo = processString2(text);
    text = mofo.toString();
    System.out.println("is text empty?: " + text.length());
    writer.write(text);
    System.out.println("text of " + pageNum + "\n " + mofo);

}

public static void main(String[] args) throws InvalidPasswordException, IOException {

    ReadPDFFile2 pdf2 = new ReadPDFFile2();
    pdf2.setFileInstance("E:\\E Books\\Novels and Story books\\Adler-Mortimer-How-To-Read-A-Book.pdf",
            "Adler-Mortimer-How-To-Read-A-Book.pdf");
    pdf2.readThisPage(3);

}

}

Answer 1

在writer上调用close（）或flush（）方法，它应该显示输出。确保清除资源。