去除两个 Json 中相同字段的方法

背景

有两个 Json 字符串，格式都一样，只是某些 value 值不同，现需要去除相同的部分，只保留不同的部分；同时需要保持 Json 格式不变（层级不变）

工具

使用 Jackson

实现

public class KeepDiffJson {

    public static void main(String[] args) throws IOException {
        ObjectMapper mapper = new ObjectMapper();

        // 第一个JSON字符串
        String json1 = "{\n" +
                "    \"name\": \"John Doe\",\n" +
                "    \"age\": 30,\n" +
                "    \"city\": \"New York\",\n" +
                "    \"married\": true,\n" +
                "    \"children\": [\n" +
                "        {\n" +
                "            \"name\": \"Alice\",\n" +
                "            \"age\": 5\n" +
                "        },\n" +
                "        {\n" +
                "            \"name\": \"Bob\",\n" +
                "            \"age\": 8\n" +
                "        }\n" +
                "    ],\n" +
                "    \"pet\": {\n" +
                "        \"a\": {\n" +
                "            \"type\": \"dog\",\n" +
                "            \"name\": \"Rex\"\n" +
                "        },\n" +
                "        \"b\": {\n" +
                "            \"type\": \"cat\",\n" +
                "            \"name\": \"Whiskers\"\n" +
                "        }\n" +
                "    }\n" +
                "}";
        // 第二个JSON字符串
        String json2 = "{\n" +
                "    \"name\": \"John Doe\",\n" +
                "    \"age\": 31,\n" +
                "    \"city\": \"New York\",\n" +
                "    \"married\": true,\n" +
                "    \"children\": [\n" +
                "        {\n" +
                "            \"name\": \"Alice...\",\n" +
                "            \"age\": 5\n" +
                "        },\n" +
                "        {\n" +
                "            \"name\": \"Bob\",\n" +
                "            \"age\": 8\n" +
                "        }\n" +
                "    ],\n" +
                "    \"pet\": {\n" +
                "        \"a\": {\n" +
                "            \"type\": \"dog1\",\n" +
                "            \"name\": \"Rex\"\n" +
                "        },\n" +
                "        \"b\": {\n" +
                "            \"type\": \"cat\",\n" +
                "            \"name\": \"Whiskers\"\n" +
                "        }\n" +
                "    }\n" +
                "}";

        // 将JSON字符串解析为JsonNode
        JsonNode node1 = mapper.readTree(json1);
        JsonNode node2 = mapper.readTree(json2);

        // 对这两个JsonNode进行比较并移除相同部分
        removeCommonParts((ObjectNode) node1, (ObjectNode) node2);

        // 将处理后的JsonNode转换回JSON字符串
        String resultJson1 = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(node1);
        String resultJson2 = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(node2);

        // System.out.println(resultJson1);
        // System.out.println(resultJson2);

        System.out.println(node1);
        System.out.println(node2);
    }

    private static void removeCommonParts(ObjectNode json1, ObjectNode json2) {
        Iterator<String> fieldNames = json1.fieldNames();
        while (fieldNames.hasNext()) {
            String fieldName = fieldNames.next();
            JsonNode value1 = json1.get(fieldName);
            JsonNode value2 = json2.get(fieldName);

            if (value2 != null) {
                if (value1.equals(value2)) {
                    fieldNames.remove();
                    json2.remove(fieldName);
                } else if (value1.isObject() && value2.isObject()) {
                    removeCommonParts((ObjectNode) value1, (ObjectNode) value2);
                } else if (value1.isArray() && value2.isArray()) {
                    removeCommonArrayElements((ArrayNode) value1, (ArrayNode) value2);
                }
            }
        }
    }

    private static void removeCommonArrayElements(ArrayNode array1, ArrayNode array2) {
        Iterator<JsonNode> iterator1 = array1.iterator();
        Iterator<JsonNode> iterator2 = array2.iterator();
        if (iterator1.hasNext() && !iterator2.hasNext()) {
            throw new RuntimeException("Json 数据格式不匹配");
        }
        if (!iterator1.hasNext() && iterator2.hasNext()) {
            throw new RuntimeException("Json 数据格式不匹配");
        }

        while (iterator1.hasNext()) {
            JsonNode item1 = iterator1.next();
            JsonNode item2 = iterator2.next();
            System.out.println("item1: " + item1 + ", item2: " + item2);

            // 方式 1：直接把数组中的 item 一次性对比
            /*if (item1.equals(item2)) {
                iterator1.remove();
                iterator2.remove();
            }*/

            // 方式 2：递归对比数组中的 item
            removeCommonParts((ObjectNode) item1, (ObjectNode) item2);
            if (item1.isEmpty()) {
                if (!item2.isEmpty()) {
                    throw new RuntimeException("Json 数据格式不匹配");
                }

                iterator1.remove();
                iterator2.remove();
            }
        }
    }

}

结果

输入：

输入.png

输出：

输出.png