JSONArray数据筛选求和

求助问答
1

求时长的和

@Test
    public void count() {
        String json = "[\n" +
                "  [\n" +
                "    {\n" +
                "      \"label\": \"时长(天)\",\n" +
                "      \"required\": true,\n" +
                "      \"name\": \"DURATION\",\n" +
                "      \"type\": \"number\",\n" +
                "      \"value\": \"0.5\",\n" +
                "      \"dateFormatType\": 0,\n" +
                "      \"editable\": false\n" +
                "    },\n" +
                "    {\n" +
                "      \"label\": \"同行人员\",\n" +
                "      \"required\": false,\n" +
                "      \"name\": \"COLLEAGUES\",\n" +
                "      \"type\": \"text\",\n" +
                "      \"editable\": false\n" +
                "    }\n" +
                "  ],\n" +
                "  [\n" +
                "    {\n" +
                "      \"label\": \"时长(天)\",\n" +
                "      \"required\": true,\n" +
                "      \"name\": \"DURATION\",\n" +
                "      \"type\": \"number\",\n" +
                "      \"value\": \"0.9\",\n" +
                "      \"dateFormatType\": 0,\n" +
                "      \"editable\": false\n" +
                "    },\n" +
                "    {\n" +
                "      \"label\": \"同行人员\",\n" +
                "      \"required\": false,\n" +
                "      \"name\": \"COLLEAGUES\",\n" +
                "      \"type\": \"text\",\n" +
                "      \"editable\": false\n" +
                "    }\n" +
                "  ]\n" +
                "]\n" +
                "\n";

        JSONArray jsonArray = JSON.parseArray(json);
        List<Object> results = jsonArray.stream().map(obj -> ((JSONArray) obj).stream().filter(arr -> {
            JSONObject jsonObject = (JSONObject) arr;
            return "DURATION".equals(jsonObject.getString("name"));
        }).map(arr -> ((JSONObject) arr).get("value"))).collect(Collectors.toList()).stream().flatMap(d -> d).collect(Collectors.toList());
        System.out.println(results);
    }
2

试试看这个？

public static BigDecimal sum(JSONArray jsonArray) {
	BigDecimal retVal = new BigDecimal(0);
	for (int i = 0; i < jsonArray.size(); i++) {
		Object json = jsonArray.get(i);
		if (json instanceof JSONArray) {
			retVal = retVal.add(sum((JSONArray) json));
		} else {
			JSONObject jsonObject = (JSONObject) json;
			if ("DURATION".equals(jsonObject.get("name"))) {
				retVal = retVal.add(jsonObject.getBigDecimal("value"));
			}
		}
	}
	return retVal;
}

我测试了一下

JSONArray jsonArray = JSON.parseArray(json);
BigDecimal result = sum(jsonArray);
System.out.println(result);  // 1.4
3

lambda版【不考虑性能】

Double sum = jsonArray.stream().map(obj -> ((JSONArray) obj).stream().filter(arr -> {
            return "DURATION".equals(((JSONObject) arr).getString("name"));
        }).mapToDouble(arr -> Double.parseDouble(((JSONObject) arr).getString("value")))).collect(Collectors.toList()).stream().flatMapToDouble(d -> d).sum();
        System.out.println(sum);
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