java - 正则表达式 - 从字符串确定矩阵

Question

如何为可能包含以下组合的字符串创建简单矩阵

123456 ABC    
123456AB1
123456AB12
123456AB123
123456

例如

if ("\\d + \\d + \\d + \\d + \\d + \\d  
   + \\s 
   + [a-zA-Z]+[a-zA-Z]+[a-zA-Z]") {
   //passed variant from input in form 123456 ABC

} else if ("\\d + \\d + \\d + \\d + \\d + \\d 
   + [a-zA-Z]+[a-zA-Z]+[a-zA-Z]
   + \\d") {
   //passed variant from input in form 123456AB1

} else if ("\\d + \\d + \\d + \\d + \\d + \\d 
   + [a-zA-Z]+[a-zA-Z]+[a-zA-Z]
   + \\d + \\d") {
   //passed variant from input in form 123456AB12

} else if ("\\d + \\d + \\d + \\d + \\d + \\d 
   + [a-zA-Z]+[a-zA-Z]+[a-zA-Z]
   + \\d + \\d + \\d") {
   //passed variant from input in form 123456AB123

} else if ("\\d + \\d + \\d + \\d + \\d + \\d") {
   //passed variant from input in form 0123456

} else {
   //doesn't match
}

Answer 1

例如，您可以使用以下正则表达式

123456 ABC  -> \\d{6}\\s\\w{3}
123456AB1   -> \\d{6}\\w{3}
123456AB12  -> \\d{6}\\w{4}
123456AB123 -> \\d{6}\\w{5}
123456      -> \\d{6}

if 子句可以在您的示例中使用，例如，

if(str.matches("\\d{6}\\s\\w+") { 
    ... 
} ...

正如您的问题一样，这些正则表达式变体仅涵盖此示例中的确切组合。