多级字符串拆分

Question

所以我的要求是这个的扩展： 在java字符串拆分后获取拆分值

我的输入字符串是这样的：

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

我需要迭代单个条件，我想知道哪个是分隔每个条件的条件运算符。

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

现在我可以使用上面链接中给出的答案找到Operands和Relational Operator 。 但是我怎样才能找到Conditional Operator并以上述格式打印呢？

Answer 1

您可以使用此包含正则表达式的代码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

Answer 2

@Warren 如果你 100% 确定输入字符串是这种格式，那么你可以简单地做这样的事情。 它更简单和直接，不需要任何正则表达式。

String[] parts = string.split(" ");

按空格分割输入字符串，然后对于每个连续的迭代，您可以像这样打印

int end = (parts.length + 1)/4;
for(int i =0;i<end;i++){
    System.out.println("Iteration : " + (i+1));

    System.out.println("Operands: [ " + parts[4*i] + " , " + parts[4*i + 2] + "]");

    System.out.println("Relational Operator: " + parts[4*i + 1]);

    System.out.println("Conditional Operator: " + ((i>0)?parts[4*i - 1]:null));
}