两个字符串数组对象需要进行比较是否相等，怎么把两个字符串对象保持顺序一致进行比较？

Question

两个字符串数组对象需要进行比较是否相等，怎么把两个字符串对象保持顺序一致进行比较？

A字符串对象：

[
    {
        "Field":"id",
        "Type":"int(11)",
        "Null":"NO",
        "Extra":"auto_increment",
        "Key":"PRI"
    },
    {
        "Field":"app_id",
        "Type":"varchar(8)",
        "Null":"YES",
        "Extra":"",
        "Key":""
    }
]

B字符串对象：

[
    {
        "Field":"id",
        "Type":"int(11)",
        "Null":"NO",
        "Key":"PRI",
        "Extra":"auto_increment"
    },
    {
        "Field":"app_id",
        "Type":"varchar(8)",
        "Null":"YES",
        "Key":"",
        "Extra":""
    }
]

A字符串对象和B字符串对象的Key和Extra键值顺序不一样，不能直接比较，怎么实现B的顺序和A的一样呢？

Answer 1

如果是希望最终比较字符串，可以先处理一下原字符串：重新按照一定规则排列对象的key，比如题主前面说的：

要实现的效果就是将A和B的所有键都按字母顺序排序一遍，怎么实现？

核心原理就是用TreeMap保证对象的key按照字典升序排列

import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONArray;
import com.alibaba.fastjson2.JSONObject;
import com.alibaba.fastjson2.JSONWriter;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.TreeMap;

public class Main {

    public static void main(String[] args) {
        String A = "[\n" +
                "    {\n" +
                "        \"Field\":\"id\",\n" +
                "        \"Type\":\"int(11)\",\n" +
                "        \"Null\":\"NO\",\n" +
                "        \"Extra\":\"auto_increment\",\n" +
                "        \"Key\":\"PRI\"\n" +
                "    },\n" +
                "    {\n" +
                "        \"Field\":\"app_id\",\n" +
                "        \"Type\":\"varchar(8)\",\n" +
                "        \"Null\":\"YES\",\n" +
                "        \"Extra\":\"\",\n" +
                "        \"Key\":\"\"\n" +
                "    }\n" +
                "]";
        String B = "[\n" +
                "    {\n" +
                "        \"Field\":\"id\",\n" +
                "        \"Type\":\"int(11)\",\n" +
                "        \"Null\":\"NO\",\n" +
                "        \"Key\":\"PRI\",\n" +
                "        \"Extra\":\"auto_increment\"\n" +
                "    },\n" +
                "    {\n" +
                "        \"Field\":\"app_id\",\n" +
                "        \"Type\":\"varchar(8)\",\n" +
                "        \"Null\":\"YES\",\n" +
                "        \"Key\":\"\",\n" +
                "        \"Extra\":\"\"\n" +
                "    }\n" +
                "]";

        String sortedKeyA = sortedKeyArray(JSON.parseArray(A));
        String sortedKeyB = sortedKeyArray(JSON.parseArray(B));

        System.out.println(sortedKeyA);
        System.out.println("---------------------------");
        System.out.println(sortedKeyB);

    }

    private static String sortedKeyArray(JSONArray array) {
        List<Map<String, Object>> list = new ArrayList<>();
        for (Object o : array) {
            JSONObject json = JSON.parseObject(JSON.toJSONString(o));
            Map<String, Object> sortedKeyMap = new TreeMap<>(json);
            list.add(sortedKeyMap);
        }
        return JSON.toJSONString(list, JSONWriter.Feature.PrettyFormat);
    }

}

输出结果：