Java正则表达式匹配器未找到所有可能的匹配项

这是因为的贪婪，

*

字串：

This order was placed for QT3000! OK?

正则表达式：

(.*)(\d+)(.*)

我们都知道那

.*

.*

?

d+

d+

d+

(.*)

This order was placed forQT300

(\d+)

0

!

现在，下一个模式将

(.*)

!<space>OK?

m.group(1)

m.group(2)

在这里查看演示。

获得所需的输出。

String line = "This order was placed for QT3000! OK?";  String pattern = "(.*)(\d{2})(.*)";  // Create a Pattern object  Pattern r = Pattern.compile(pattern);  // Now create matcher object.  Matcher m = r.matcher(line);  while(m.find( )) {     System.out.println("Found value: " + m.group(1));     System.out.println("Found value: " + m.group(2));     System.out.println("Found value: " + m.group(3));  }

输出：

Found value: This order was placed for QT30Found value: 00Found value: ! OK?

(.*)(\d{2})

改变你的模式，

String pattern = "(.*?)(\d+)(.*)";

要获得类似的输出，

Found value: This order was placed for QTFound value: 3000Found value: ! OK?

?

*

*

使用额外的捕获组从单个程序获取输出。

String line = "This order was placed for QT3000! OK?";String pattern = "((.*?)(\d{2}))(?:(\d{2})(.*))";Pattern r = Pattern.compile(pattern);      Matcher m = r.matcher(line);      while(m.find( )) {         System.out.println("Found value: " + m.group(1));         System.out.println("Found value: " + m.group(4));         System.out.println("Found value: " + m.group(5));         System.out.println("Found value: " + m.group(2));         System.out.println("Found value: " + m.group(3) + m.group(4));         System.out.println("Found value: " + m.group(5));     }

输出：

Found value: This order was placed for QT30Found value: 00Found value: ! OK?Found value: This order was placed for QTFound value: 3000Found value: ! OK?