Question

我有正则表达式，应删除注释（多行，单行）

(\s*\/\/.*)|((\/\*)(.|\n)+?(\*\/))

当我在Sublime或网站上查看时，它对我来说没问题。但是当我在程序中使用它时，它没有正常工作。这就是我的意思。

/**
 * Base class from which all RMI-IIOP stubs must inherit.
 */

public abstract class Stub extends ObjectImpl
implements java.io.Serializable {

// This can only be set at object construction time (no sync necessary).
private transient StubDelegate stubDelegate = null;

regexp仅匹配单行注释，但在其他文本编辑器中，它适用于所有类型。

这是我的代码：

FileInputStream fis = new FileInputStream(filePath);
    BufferedReader br = new BufferedReader(new InputStreamReader(fis));
    String strLine;
    while ((strLine = br.readLine()) != null) {
        Matcher m = Pattern.compile(delCommentsPattern,Pattern.MULTILINE).matcher(strLine);
        while (m.find()) {
            String b = m.group();
            System.out.println(b);
  }
}

我做错了什么？

UPD：添加delCommentsPattern：

 private String delCommentsPattern ="(\\s*\\/\\/.*)|((\\/\\*)(.|\\n)+?(\\*\\/))";

UPD2：我已经完成了，RAVI推荐了什么，但现在我有一个例外，当我在更大的文件上使用它时：

    Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
    at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Node.fireEvent(Node.java:8411)
    at javafx.scene.control.Button.fire(Button.java:185)
    at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
    at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
    at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
    at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
    at javafx.event.Event.fireEvent(Event.java:198)
    at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
    at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
    at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:380)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:294)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:416)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:415)
    at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
    at com.sun.glass.ui.View.notifyMouse(View.java:937)
    at com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
    at com.sun.glass.ui.gtk.GtkApplication.lambda$null$49(GtkApplication.java:139)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
    ... 48 more
Caused by: java.lang.StackOverflowError
    at java.util.regex.Pattern$LazyLoop.match(Pattern.java:4843)
    at java.util.regex.Pattern$GroupTail.match(Pattern.java:4717)
    at java.util.regex.Pattern$BranchConn.match(Pattern.java:4568)
    at java.util.regex.Pattern$CharProperty.match(Pattern.java:3777)
    at java.util.regex.Pattern$Branch.match(Pattern.java:4604)
    at java.util.regex.Pattern$GroupHead.match(Pattern.java:4658)
    at java.util.regex.Pattern$LazyLoop.match(Pattern.java:4847)
    at java.util.regex.Pattern$GroupTail.match(Pattern.java:4717)
    at java.util.regex.Pattern$BranchConn.match(Pattern.java:4568)
    at java.util.regex.Pattern$CharProperty.match(Pattern.java:3777)
    at java.util.regex.Pattern$Branch.match(Pattern.java:4604)
    at java.util.regex.Pattern$GroupHead.match(Pattern.java:4658)
    at java.util.regex.Pattern$LazyLoop.match(Pattern.java:4847)
    at java.util.regex.Pattern$GroupTail.match(Pattern.java:4717)
    at java.util.regex.Pattern$BranchConn.match(Pattern.java:4568)
    at java.util.regex.Pattern$CharProperty.match(Pattern.java:3777)
    at java.util.regex.Pattern$Branch.match(Pattern.java:4604)
    at java.util.regex.Pattern$GroupHead.match(Pattern.java:4658)
    at java.util.regex.Pattern$LazyLoop.match(Pattern.java:4847)
    at java.util.regex.Pattern$GroupTail.match(Pattern.java:4717)
    at java.util.regex.Pattern$BranchConn.match(Pattern.java:4568)
    at java.util.regex.Pattern$CharProperty.match(Pattern.java:3777)
    at java.util.regex.Pattern$Branch.match(Pattern.java:4604)
    at java.util.regex.Pattern$GroupHead.match(Pattern.java:4658)
    at java.util.regex.Pattern$LazyLoop.match(Pattern.java:4847)
    at java.util.regex.Pattern$GroupTail.match(Pattern.java:4717)
    at java.util.regex.Pattern$BranchConn.match(Pattern.java:4568)
    at java.util.regex.Pattern$CharProperty.match(Pattern.java:3777)

Answer 1

由于您逐行读取文件，因此正则表达式无法匹配跨越多行的文本。您需要先将整个文件读入一个字符串，然后执行while循环。

但请注意，您的正则表达式在以下代码中存在问题，看起来它开始发表评论：

List<File> files = FileUtils.find("src/*.java");   // Note the /*

您应该使用Java标记生成器并过滤其输出以进行注释，而不是正则表达式。 https://github.com/javaparser/javaparser看起来像是这项工作的合适工具。它甚至有一些test cases用于解析注释。

Answer 2

正如其他人所说，在运行此正则表达式之前，必须将整个文件读入字符串。

请注意，为了解析注释，您必须在同一个分析字符串 时间，否则任何一个都可以隐藏在另一个中。

这是弦乐的正则表达式由于您正在删除评论，因此此正则表达式会保留格式设置以便进行清除移除后看起来并没有结合在一起。

"(?m)((?:(?:^[ \\t]*)?(?:/\\*[^*]*\\*+(?:[^/*][^*]*\\*+)*/(?:[ \\t]*\\r?\\n(?=[ \\t]*(?:\\r?\\n|/\\*|//)))?|//(?:[^\\\\]|\\\\(?:\\r?\\n)?)*?(?:\\r?\\n(?=[ \\t]*(?:\\r?\\n|/\\*|//))|(?=\\r?\\n))))+)|(\"[^\"\\\\]*(?:\\\\[\\S\\s][^\"\\\\]*)*\"|'[^'\\\\]*(?:\\\\[\\S\\s][^'\\\\]*)*'|(?:\\r?\\n|[\\S\\s])[^/\"'\\\\\\s]*)"

将全部替换为$2。

说明（如果需要）

   (?m)                             # Multi-line modifier
   (                                # (1 start), Comments 
        (?:
             (?: ^ [ \t]* )?                  # <- To preserve formatting
             (?:
                  /\*                              # Start /* .. */ comment
                  [^*]* \*+
                  (?: [^/*] [^*]* \*+ )*
                  /                                # End /* .. */ comment
                  (?:                              # <- To preserve formatting 
                       [ \t]* \r? \n                                      
                       (?=
                            [ \t]*                  
                            (?: \r? \n | /\* | // )
                       )
                  )?
               |  
                  //                               # Start // comment
                  (?:                              # Possible line-continuation
                       [^\\] 
                    |  \\ 
                       (?: \r? \n )?
                  )*?
                  (?:                              # End // comment
                       \r? \n                               
                       (?=                              # <- To preserve formatting
                            [ \t]*                          
                            (?: \r? \n | /\* | // )
                       )
                    |  (?= \r? \n )
                  )
             )
        )+                               # Grab multiple comment blocks if need be
   )                                # (1 end)

|                                 ## OR

   (                                # (2 start), Non - comments 
        "
        [^"\\]*                          # Double quoted text
        (?: \\ [\S\s] [^"\\]* )*
        "
     |  '
        [^'\\]*                          # Single quoted text
        (?: \\ [\S\s] [^'\\]* )*
        ' 
     |  (?: \r? \n | [\S\s] )            # Linebreak or Any other char
        [^/"'\\\s]*                      # Chars which doesn't start a comment, string, escape,
                                         # or line continuation (escape + newline)
   )                                # (2 end)

Answer 3

由于您正在逐行处理，因此无法正常工作。

首先，您需要读取字符串中的完整文件。然后在上面使用正则表达式。

String strLine;
StringBuffer sb = new StringBuffer("");
while ((strLine = br.readLine()) != null) {
    sb.append(strLine + "\n");
}

Matcher m = Pattern.compile(delCommentsPattern,Pattern.MULTILINE).matcher(sb.toString());
while (m.find()) {
    String b = m.group();
    System.out.println(b);
}

Answer 4

如果我正确理解你要做的事情（即提取注释），请尝试使用此字符串作为Java中的正则表达式：

String regex = "(/\\*\\*.*\\*/)|(//.*?$)";

顺便说一句，你必须确保你逃避星号和其他保留字符。另一件事是你需要读取文件，如果你想做多行正则表达式（即如果正则表达式正在寻找多行注释，你就不能在一行上匹配）。

请务必使用DOTALL和MULTILINE

代码示例：

public static void main(String[] args) throws Exception {
    String text = readStream(new FileInputStream("test.txt"));
    Matcher m = Pattern.compile("(/\\*\\*.*\\*/)|(//.*?$)", Pattern.MULTILINE | Pattern.DOTALL).matcher(text);
    while (m.find()) {
        String b = m.group();
        System.out.println("GROUP: "+b);
    }
}

public static String readStream(InputStream is) {
    StringBuilder sb = new StringBuilder(512);
    try {
        Reader r = new InputStreamReader(is, "UTF-8");
        int c = 0;
        while ((c = r.read()) != -1) {
            sb.append((char) c);
        }
    } catch (IOException e) {
        throw new RuntimeException(e);
    }
    return sb.toString();
}

Regexp并不匹配所有

4 个答案: