java - 多级字符串分割

Question

所以我的要求是这个的扩展:Obtaining the split value after java string split

我的输入字符串是这样的:

FEES_1 > 100 AND FEES_2 <= 200 OR FEES_3 <= 500

我需要迭代各个条件，并且我想知道分隔每个条件的条件运算符是什么。

预期输出:-

Iteration 1:
Operands: [FEES_1 ,  100 ]
Relational Operator: >
Conditional Operator: null

Iteration 2:
Operands: [FEES_2 ,  200 ]
Relational Operator: <=
Conditional Operator: AND

Operands: [FEES_3 ,  500 ]
Relational Operator: <=
Conditional Operator: OR

现在我可以找到Operands和Relational Operator使用上面链接中给出的答案。 但我怎样才能找到Conditional Operator并按上述格式打印？

Answer 1

您可以使用包含正则表达式的代码来根据您的需要解析值。

public static void main(String[] args) {
    String str = "FEES_1 > 100 AND FEES_2 <= 200 OR FEES_3 <= 500";
    Pattern p = Pattern.compile("(?:^|(AND|OR))\\s*(\\w+)\\s+([<>]=?)\\s+(\\d+)\\s*(?=(AND|OR|$))");
    Matcher m = p.matcher(str);
    for (int i = 0; m.find(); i++) {
        System.out.println("Iteration " + (i + 1) + ":");
        System.out.println(String.format("Operands: [%s ,  %s ]", m.group(2), m.group(4)));
        System.out.println("Relational Operator: " + m.group(3));
        System.out.println("Conditional Operator: " + m.group(1));
        System.out.println();
    }
}

此代码提供了与您想要的完全匹配的以下输出。

Iteration 1:
Operands: [FEES_1 ,  100 ]
Relational Operator: >
Conditional Operator: null

Iteration 2:
Operands: [FEES_2 ,  200 ]
Relational Operator: <=
Conditional Operator: AND

Iteration 3:
Operands: [FEES_3 ,  500 ]
Relational Operator: <=
Conditional Operator: OR