在Java中使用模式匹配提取数据

Question

I have a requriement in Java to extarct data from the big string using Pattern.compile() .

INPUT STRING :

[{"KEY1" :"VALUE1","KEY2" :"VALUE2","KEY3" :"VALUE3","KEY4" :"VALUE4"},{"KEY1" :"VALUE5","KEY2" :"VALUE6","KEY3" :"VALUE7","KEY4" :"VALUE8"}]

OUTPUT : set of 2 string

first :  {"KEY1" :"VALUE1","KEY2" :"VALUE2","KEY3" :"VALUE3","KEY4" :"VALUE4"}
second : {"KEY1" :"VALUE5","KEY2" :"VALUE6","KEY3" :"VALUE7","KEY4" :"VALUE8"}

I am trying below code :

     ArrayList<String> token_data = new ArrayList<String>();

     String myString = "[{"KEY1" :"VALUE1","KEY2" :"VALUE2","KEY3" :"VALUE3","KEY4" :"VALUE4"},{"KEY1" :"VALUE5","KEY2" :"VALUE6","KEY3" :"VALUE7","KEY4" :"VALUE8"}]"
        System.out.println(myString);
        Pattern p1 = Pattern.compile("\"([^\"]+)\"");
        Matcher m = p1.matcher(myString);

        while(m.find())
        {

            System.out.println(m.group(1)); 
            //m.group(1);
            token_data.add(m.group(1));
        }

Answer 1

If I understood you correctly, here is the regex: {(.*)} . Note, that you need to mark it as ungreedy.

Regex demo: https://regex101.com/r/x6ZX56/2

Result:

1

Full match: {"KEY1" :"VALUE1","KEY2" :"VALUE2","KEY3" :"VALUE3","KEY4" :"VALUE4"}

Group 1: "KEY1" :"VALUE1","KEY2" :"VALUE2","KEY3" :"VALUE3","KEY4" :"VALUE4"

2

Full match: {"KEY1" :"VALUE5","KEY2" :"VALUE6","KEY3" :"VALUE7","KEY4" :"VALUE8"}

Group 1: "KEY1" :"VALUE5","KEY2" :"VALUE6","KEY3" :"VALUE7","KEY4" :"VALUE8"

Java example:

    String input = "[{\"KEY1\" :\"VALUE1\",\"KEY2\" :\"VALUE2\",\"KEY3\" :\"VALUE3\",\"KEY4\" :\"VALUE4\"},{\"KEY1\" :\"VALUE5\",\"KEY2\" :\"VALUE6\",\"KEY3\" :\"VALUE7\",\"KEY4\" :\"VALUE8\"}]";

    Pattern pattern = Pattern.compile("\\{(.*?)}");

    Matcher m = pattern.matcher(input);

    while (m.find()) {
        System.out.println(m.group(1));
    }

Note, that I used escaping characters for the input string.