在Java中从字符串中高效提取JSON数组值：库解析与正则表达式实践

{
   "values":[
      "abc123",
      "def456",
      "xyz789"
   ]
}

import java.util.List;

public class MyPojo {
    private List<String> values;

    // 构造函数
    public MyPojo() {}

    // Getter
    public List<String> getValues() {
        return values;
    }

    // Setter
    public void setValues(List<String> values) {
        this.values = values;
    }

    @Override
    public String toString() {
        return "MyPojo{" +
               "values=" + values +
               '}';
    }
}

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.json.JsonMapper;
import java.util.List;

public class JsonParsingExample {

    public static void main(String[] args) throws Exception {
        String jsonStr = "{
" +
                         "   "values":[
" +
                         "      "abc123",
" +
                         "      "def456",
" +
                         "      "xyz789"
" +
                         "   ]
" +
                         "}";

        ObjectMapper mapper = new JsonMapper();
        MyPojo pojo = mapper.readValue(jsonStr, MyPojo.class);
        System.out.println("通过POJO映射获取的值: " + pojo.getValues());
        // 输出: 通过POJO映射获取的值: [abc123, def456, xyz789]
    }
}

import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.json.JsonMapper;
import com.fasterxml.jackson.core.type.TypeReference;
import java.util.List;

public class JsonTreeParsingExample {

    public static void main(String[] args) throws Exception {
        String jsonStr = "{
" +
                         "   "values":[
" +
                         "      "abc123",
" +
                         "      "def456",
" +
                         "      "xyz789"
" +
                         "   ]
" +
                         "}";

        ObjectMapper mapper = new JsonMapper();
        JsonNode rootNode = mapper.readTree(jsonStr); // 解析为根节点
        JsonNode valuesNode = rootNode.get("values"); // 获取名为"values"的节点

        if (valuesNode != null && valuesNode.isArray()) {
            // 将JsonNode转换为List<String>
            List<String> values = mapper.readerFor(new TypeReference<List<String>>() {}).readValue(valuesNode);
            System.out.println("通过Tree模型解析获取的值:");
            values.forEach(System.out::println);
            /*
            输出:
            abc123
            def456
            xyz789
            */
        } else {
            System.out.println("未找到'values'数组或其格式不正确。");
        }
    }
}

import java.util.Arrays;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

public class RegexParsingExample {

    public static void main(String[] args) {
        String logOutput = "[INFO][2022-11-11] Response body : 
" +
                           "{
" +
                           "   "values":[
" +
                           "      "abc123",
" +
                           "      "def456",
" +
                           "      "xyz789"
" +
                           "   ]
" +
                           "}";

        // 匹配"values": 后面的整个数组内容，捕获到组1中
        Pattern pattern = Pattern.compile(""values"\s*:\s*\[(.+?)]");
        Matcher matcher = pattern.matcher(logOutput);

        List<String> values = List.of(); // 初始化为空列表

        if (matcher.find()) {
            String arrayContent = matcher.group(1); // 获取捕获的数组内容，例如："abc123", "def456", "xyz789"
            values = Arrays.stream(arrayContent.split(",")) // 按逗号分割
                         .map(s -> s.replaceAll(""", "").strip()) // 移除引号并去除首尾空格
                         .collect(Collectors.toList());
        }

        System.out.println("通过正则表达式解析获取的值:");
        values.forEach(System.out::println);
        /*
        输出:
        abc123
        def456
        xyz789
        */
    }
}