多级字符串拆分

Question

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: nullIteration 2:Operands: [FEES_2 ,  200 ]Relational Operator: <=Conditional Operator: ANDOperands: [FEES_3 ,  500 ]Relational Operator: <=Conditional Operator: OR现在我可以找到Operands并Relational Operator使用上面链接中给出的答案。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

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));

}