java - 匹配非多行正则表达式

Question

我有以下文件内容，我正在尝试匹配下面解释的注册表:

-- file.txt (doesn't match single/in-line text) -- 
test On blah more blah wrote:
blah blah blah
blah blah
blah
---------------

如果我从上面读取文件内容到字符串并尝试匹配“On...wrote:”部分，我无法获得匹配:

    // String text = <file contents from above>
    Pattern PATTERN = Pattern.compile("^(On\\s(.+)wrote:)$");
    Matcher m = PATTERN.matcher(text);
    if (m.find()) {
       System.out.println("Never gets HERE???");
       // TODO: Strip out all characters after the match and any \s or \n before
    }

本质上我想要以下输出:

-- file2.txt -- 
test    
---------------

Answer 1

也许这可以帮助您获得您想要的结果:

        String text = "test On blah more blah wrote:\n" 
                + "blah blah blah\nblah blah\nblah\n";
        StringWriter sw = new StringWriter();
        PrintWriter pw = new PrintWriter(sw);
        Pattern PATTERN = Pattern.compile("^(.*?)\\s*On\\s(.+)wrote:$", 
                Pattern.MULTILINE);
        Matcher m = PATTERN.matcher(text);
        if (m.find()) {
            pw.println(m.group(1));
        }
        pw.close();
        System.out.println(sw);

Pattern.MULTILINE javadoc:在多行模式下，表达式 ^ 和 $ 分别匹配行终止符之后或之前 ...我还添加了 (.*?) 来匹配所有内容在第一个“On”之前。