java 如何从 JSON 对象获取数组？

How to get array from JSON Object?

提问by marius_ll

i want to get the array of json objects from a json object. But it doesnt work. Can anybody help me?

我想从 json 对象中获取 json 对象数组。但它不起作用。有谁能够帮我？

The output is:

输出是：

Exception in thread "main" org.json.JSONException: JSONObject["value"] not 
found.

Source Code:

源代码：

import org.json.*;

public class JsonIO {

public static void parseJson(StringBuffer sb){

    JSONObject obj = new JSONObject(sb);

    JSONArray arr = obj.getJSONArray("value");

    for (int i = 0; i< arr.length(); i++){
        System.out.println(arr.getJSONObject(i).getString("Name"));
    }
}

}

The input is:

输入是：

{  "@odata.context":"https://www.nameofshop......de/odata/$metadata#Product","value":[    {      "ProductTypeId":5,"ParentGroupedProductId":0,"VisibleIndividually":true,"Name":"Build your own computer","ShortDescription":"Build it","FullDescription":"<p>Fight back against cluttered workspaces with the stylish IBM zBC12 All-in-One desktop PC, featuring powerful computing resources and a stunning 20.1-inch widescreen display with stunning XBRITE-HiColor LCD technology. The black IBM zBC12 has a built-in microphone and MOTION EYE camera with face-tracking technology that allows for easy communication with friends and family. And it has a built-in DVD burner and Sony's Movie Store software so you can create a digital entertainment library for personal viewing at your convenience. Easy to setup and even easier to use, this JS-series All-in-One includes an elegantly designed keyboard and a USB mouse.</p>","AdminComment":null,"ProductTemplateId":1,"VendorId":0,"ShowOnHomePage":true,"MetaKeywords":null,"MetaDescription":null,"MetaTitle":null,"AllowCustomerReviews":true,"ApprovedRatingSum":0,"NotApprovedRatingSum":0,"ApprovedTotalReviews":0,"NotApprovedTotalReviews":0,"SubjectToAcl":false,"LimitedToStores":false,"Sku":null,"ManufacturerPartNumber":null,"Gtin":null,"IsGiftCard":false,"GiftCardTypeId":0,"OverriddenGiftCardAmount":null,"RequireOtherProducts":false,"RequiredProductIds":null,"AutomaticallyAddRequiredProducts":false,"IsDownload":false,"DownloadId":0,"UnlimitedDownloads":false,"MaxNumberOfDownloads":0,"DownloadExpirationDays":null,"DownloadActivationTypeId":0,"HasSampleDownload":false,"SampleDownloadId":0,"HasUserAgreement":false,"UserAgreementText":null,"IsRecurring":false,"RecurringCycleLength":0,"RecurringCyclePeriodId":0,"RecurringTotalCycles":0,"IsRental":false,"RentalPriceLength":0,"RentalPricePeriodId":0,"IsShipEnabled":true,"IsFreeShipping":true,"ShipSeparately":false,"AdditionalShippingCharge":0.0000,"DeliveryDateId":0,"IsTaxExempt":false,"TaxCategoryId":2,"IsTelecommunicationsOrBroadcastingOrElectronicServices":false,"ManageInventoryMethodId":1,"UseMultipleWarehouses":false,"WarehouseId":0,"StockQuantity":10000,"DisplayStockAvailability":true,"DisplayStockQuantity":false,"MinStockQuantity":0,"LowStockActivityId":1,"NotifyAdminForQuantityBelow":1,"BackorderModeId":0,"AllowBackInStockSubscriptions":false,"OrderMinimumQuantity":1,"OrderMaximumQuantity":10000,"AllowedQuantities":null,"AllowAddingOnlyExistingAttributeCombinations":false,"DisableBuyButton":false,"DisableWishlistButton":false,"AvailableForPreOrder":false,"PreOrderAvailabilityStartDateTimeUtc":null,"CallForPrice":false,"Price":1200.0000,"OldPrice":0.0000,"ProductCost":0.0000,"SpecialPrice":null,"SpecialPriceStartDateTimeUtc":null,"SpecialPriceEndDateTimeUtc":null,"CustomerEntersPrice":false,"MinimumCustomerEnteredPrice":0.0000,"MaximumCustomerEnteredPrice":0.0000,"BasepriceEnabled":false,"BasepriceAmount":0.0000,"BasepriceUnitId":0,"BasepriceBaseAmount":0.0000,"BasepriceBaseUnitId":0,"MarkAsNew":true,"MarkAsNewStartDateTimeUtc":null,"MarkAsNewEndDateTimeUtc":null,"HasTierPrices":false,"HasDiscountsApplied":false,"Weight":2.0000,"Length":2.0000,"Width":2.0000,"Height":2.0000,"AvailableStartDateTimeUtc":null,"AvailableEndDateTimeUtc":null,"DisplayOrder":0,"Published":true,"Deleted":true,"CreatedOnUtc":"2016-04-19T11:41:10.163+01:00","UpdatedOnUtc":"2016-04-19T11:41:10.163+01:00","ProductType":"SimpleProduct","BackorderMode":"NoBackorders","DownloadActivationType":"0","GiftCardType":"Virtual","LowStockActivity":"DisableBuyButton","ManageInventoryMethod":"ManageStock","RecurringCyclePeriod":"Days","RentalPricePeriod":"Days","Id":1    },{      "ProductTypeId":5,"ParentGroupedProductId":0,"VisibleIndividually":true,"Name":"Digital Storm VANQUISH 3 Custom Performance PC","ShortDescription":"Digital Storm Vanquish 3 Desktop PC","FullDescription":"<p>Blow the doors off today\u2019s most demanding games with maximum detail, speed, and power for an immersive gaming experience without breaking the bank.</p><p>Stay ahead of the competition, VANQUISH 3 is fully equipped to easily handle future upgrades, keeping your system on the cutting edge for years to come.</p><p>Each system is put through an extensive stress test, ensuring you experience zero bottlenecks and get the maximum performance from your hardware.</p>","AdminComment":null,"ProductTemplateId":1,"VendorId":0,"ShowOnHomePage":false,"MetaKeywords":null,"MetaDescription":null,"MetaTitle":null,"AllowCustomerReviews":true,"ApprovedRatingSum":0,"NotApprovedRatingSum":0,"ApprovedTotalReviews":0,"NotApprovedTotalReviews":0,"SubjectToAcl":false,"LimitedToStores":false,"Sku":null,"ManufacturerPartNumber":null,"Gtin":null,"IsGiftCard":false,"GiftCardTypeId":0,"OverriddenGiftCardAmount":null,"RequireOtherProducts":false,"RequiredProductIds":null,"AutomaticallyAddRequiredProducts":false,"IsDownload":false,"DownloadId":0,"UnlimitedDownloads":false,"MaxNumberOfDownloads":0,"DownloadExpirationDays":null,"DownloadActivationTypeId":0,"HasSampleDownload":false,"SampleDownloadId":0,"HasUserAgreement":false,"UserAgreementText":null,"IsRecurring":false,"RecurringCycleLength":0,"RecurringCyclePeriodId":0,"RecurringTotalCycles":0,"IsRental":false,"RentalPriceLength":0,"RentalPricePeriodId":0,"IsShipEnabled":true,"IsFreeShipping":false,"ShipSeparately":false,"AdditionalShippingCharge":0.0000,"DeliveryDateId":0,"IsTaxExempt":false,"TaxCategoryId":2,"IsTelecommunicationsOrBroadcastingOrElectronicServices":false,"ManageInventoryMethodId":1,"UseMultipleWarehouses":false,"WarehouseId":0,"StockQuantity":10000,"DisplayStockAvailability":true,"DisplayStockQuantity":false,"MinStockQuantity":0,"LowStockActivityId":1,"NotifyAdminForQuantityBelow":1,"BackorderModeId":0,"AllowBackInStockSubscriptions":false,"OrderMinimumQuantity":1,"OrderMaximumQuantity":10000,"AllowedQuantities":null,"AllowAddingOnlyExistingAttributeCombinations":false,"DisableBuyButton":false,"DisableWishlistButton":false,"AvailableForPreOrder":false,"PreOrderAvailabilityStartDateTimeUtc":null,"CallForPrice":false,"Price":1259.0000,"OldPrice":0.0000,"ProductCost":0.0000,"SpecialPrice":null,"SpecialPriceStartDateTimeUtc":null,"SpecialPriceEndDateTimeUtc":null,"CustomerEntersPrice":false,"MinimumCustomerEnteredPrice":0.0000,"MaximumCustomerEnteredPrice":0.0000,"BasepriceEnabled":false,"BasepriceAmount":0.0000,"BasepriceUnitId":0,"BasepriceBaseAmount":0.0000,"BasepriceBaseUnitId":0,"MarkAsNew":false,"MarkAsNewStartDateTimeUtc":null,"MarkAsNewEndDateTimeUtc":null,"HasTierPrices":false,"HasDiscountsApplied":false,"Weight":7.0000,"Length":7.0000,"Width":7.0000,"Height":7.0000,"AvailableStartDateTimeUtc":null,"AvailableEndDateTimeUtc":null,"DisplayOrder":0,"Published":true,"Deleted":true,"CreatedOnUtc":"2016-04-19T11:41:12.177+01:00","UpdatedOnUtc":"2016-04-19T11:41:12.177+01:00","ProductType":"SimpleProduct","BackorderMode":"NoBackorders","DownloadActivationType":"0","GiftCardType":"Virtual","LowStockActivity":"DisableBuyButton","ManageInventoryMethod":"ManageStock","RecurringCyclePeriod":"Days","RentalPricePeriod":"Days","Id":2    }

回答by Rajkumar

The exception occurred because your input JSON string is not properly assigned to JSONObject. There is no constructor like JSONObject(StringBuffer). Just Change it to JSONObject(String) or JSONObject(StringBufferObject.toString())

发生异常是因为您的输入 JSON 字符串未正确分配给 JSONObject。没有像 JSONObject(StringBuffer) 这样的构造函数。只需将其更改为 JSONObject(String) 或 JSONObject(StringBufferObject.toString())

also, add ]}at the end of your input JSON string.

此外，]}在输入 JSON 字符串的末尾添加。

public static void parseJson(StringBuffer sb) throws JSONException {

    JSONObject obj = new JSONObject(sb.toString());


    JSONArray arr = obj.getJSONArray("value");

    for (int i = 0; i < arr.length(); i++) {
        System.out.println(arr.getJSONObject(i).getString("Name"));
    }
}

回答by Tanmay Delhikar

Well, it works for me in my environment. Add " ]}" at the end.

嗯，它在我的环境中对我有用。]}在末尾添加“ ”。

回答by marius_ll

Thanks for the help. The Problem was the StringBuffer. I have used the .toString function of StringBuffer and everything works.

谢谢您的帮助。问题是 StringBuffer。我使用了 StringBuffer 的 .toString 函数，一切正常。

回答by Oguz

You can use GSON lib. Here you can download.

您可以使用 GSON 库。在这里你可以下载。

public static void parseJson(String sb){

 JsonParser jsonParser = new JsonParser();
 JsonObject jo = (JsonObject)jsonParser.parse(sb);
 JsonArray jArray = jo.getAsJsonArray("value"); // get json array

 Gson gJson = new Gson();
 ArrayList jsonObjArrayList = gJson.fromJson(jArray, ArrayList.class);


 for (int i = 0; i< jsonObjArrayList.size(); i++){
    System.out.println(jsonObjArrayList.get(i).toString());
 }
}

回答by Joey Pinto

Considering the JSON

考虑 JSON

{  "@odata.context":"https://www.nameofshop......de/odata/$metadata#Product","value":[    {      "ProductTypeId":5,"ParentGroupedProductId":0,"VisibleIndividually":true,"Name":"Build your own computer","ShortDescription":"Build it","FullDescription":"<p>Fight back against cluttered workspaces with the stylish IBM zBC12 All-in-One desktop PC, featuring powerful computing resources and a stunning 20.1-inch widescreen display with stunning XBRITE-HiColor LCD technology. The black IBM zBC12 has a built-in microphone and MOTION EYE camera with face-tracking technology that allows for easy communication with friends and family. And it has a built-in DVD burner and Sony's Movie Store software so you can create a digital entertainment library for personal viewing at your convenience. Easy to setup and even easier to use, this JS-series All-in-One includes an elegantly designed keyboard and a USB mouse.</p>","AdminComment":null,"ProductTemplateId":1,"VendorId":0,"ShowOnHomePage":true,"MetaKeywords":null,"MetaDescription":null,"MetaTitle":null,"AllowCustomerReviews":true,"ApprovedRatingSum":0,"NotApprovedRatingSum":0,"ApprovedTotalReviews":0,"NotApprovedTotalReviews":0,"SubjectToAcl":false,"LimitedToStores":false,"Sku":null,"ManufacturerPartNumber":null,"Gtin":null,"IsGiftCard":false,"GiftCardTypeId":0,"OverriddenGiftCardAmount":null,"RequireOtherProducts":false,"RequiredProductIds":null,"AutomaticallyAddRequiredProducts":false,"IsDownload":false,"DownloadId":0,"UnlimitedDownloads":false,"MaxNumberOfDownloads":0,"DownloadExpirationDays":null,"DownloadActivationTypeId":0,"HasSampleDownload":false,"SampleDownloadId":0,"HasUserAgreement":false,"UserAgreementText":null,"IsRecurring":false,"RecurringCycleLength":0,"RecurringCyclePeriodId":0,"RecurringTotalCycles":0,"IsRental":false,"RentalPriceLength":0,"RentalPricePeriodId":0,"IsShipEnabled":true,"IsFreeShipping":true,"ShipSeparately":false,"AdditionalShippingCharge":0.0000,"DeliveryDateId":0,"IsTaxExempt":false,"TaxCategoryId":2,"IsTelecommunicationsOrBroadcastingOrElectronicServices":false,"ManageInventoryMethodId":1,"UseMultipleWarehouses":false,"WarehouseId":0,"StockQuantity":10000,"DisplayStockAvailability":true,"DisplayStockQuantity":false,"MinStockQuantity":0,"LowStockActivityId":1,"NotifyAdminForQuantityBelow":1,"BackorderModeId":0,"AllowBackInStockSubscriptions":false,"OrderMinimumQuantity":1,"OrderMaximumQuantity":10000,"AllowedQuantities":null,"AllowAddingOnlyExistingAttributeCombinations":false,"DisableBuyButton":false,"DisableWishlistButton":false,"AvailableForPreOrder":false,"PreOrderAvailabilityStartDateTimeUtc":null,"CallForPrice":false,"Price":1200.0000,"OldPrice":0.0000,"ProductCost":0.0000,"SpecialPrice":null,"SpecialPriceStartDateTimeUtc":null,"SpecialPriceEndDateTimeUtc":null,"CustomerEntersPrice":false,"MinimumCustomerEnteredPrice":0.0000,"MaximumCustomerEnteredPrice":0.0000,"BasepriceEnabled":false,"BasepriceAmount":0.0000,"BasepriceUnitId":0,"BasepriceBaseAmount":0.0000,"BasepriceBaseUnitId":0,"MarkAsNew":true,"MarkAsNewStartDateTimeUtc":null,"MarkAsNewEndDateTimeUtc":null,"HasTierPrices":false,"HasDiscountsApplied":false,"Weight":2.0000,"Length":2.0000,"Width":2.0000,"Height":2.0000,"AvailableStartDateTimeUtc":null,"AvailableEndDateTimeUtc":null,"DisplayOrder":0,"Published":true,"Deleted":true,"CreatedOnUtc":"2016-04-19T11:41:10.163+01:00","UpdatedOnUtc":"2016-04-19T11:41:10.163+01:00","ProductType":"SimpleProduct","BackorderMode":"NoBackorders","DownloadActivationType":"0","GiftCardType":"Virtual","LowStockActivity":"DisableBuyButton","ManageInventoryMethod":"ManageStock","RecurringCyclePeriod":"Days","RentalPricePeriod":"Days","Id":1    },{      "ProductTypeId":5,"ParentGroupedProductId":0,"VisibleIndividually":true,"Name":"Digital Storm VANQUISH 3 Custom Performance PC","ShortDescription":"Digital Storm Vanquish 3 Desktop PC","FullDescription":"<p>Blow the doors off today\u2019s most demanding games with maximum detail, speed, and power for an immersive gaming experience without breaking the bank.</p><p>Stay ahead of the competition, VANQUISH 3 is fully equipped to easily handle future upgrades, keeping your system on the cutting edge for years to come.</p><p>Each system is put through an extensive stress test, ensuring you experience zero bottlenecks and get the maximum performance from your hardware.</p>","AdminComment":null,"ProductTemplateId":1,"VendorId":0,"ShowOnHomePage":false,"MetaKeywords":null,"MetaDescription":null,"MetaTitle":null,"AllowCustomerReviews":true,"ApprovedRatingSum":0,"NotApprovedRatingSum":0,"ApprovedTotalReviews":0,"NotApprovedTotalReviews":0,"SubjectToAcl":false,"LimitedToStores":false,"Sku":null,"ManufacturerPartNumber":null,"Gtin":null,"IsGiftCard":false,"GiftCardTypeId":0,"OverriddenGiftCardAmount":null,"RequireOtherProducts":false,"RequiredProductIds":null,"AutomaticallyAddRequiredProducts":false,"IsDownload":false,"DownloadId":0,"UnlimitedDownloads":false,"MaxNumberOfDownloads":0,"DownloadExpirationDays":null,"DownloadActivationTypeId":0,"HasSampleDownload":false,"SampleDownloadId":0,"HasUserAgreement":false,"UserAgreementText":null,"IsRecurring":false,"RecurringCycleLength":0,"RecurringCyclePeriodId":0,"RecurringTotalCycles":0,"IsRental":false,"RentalPriceLength":0,"RentalPricePeriodId":0,"IsShipEnabled":true,"IsFreeShipping":false,"ShipSeparately":false,"AdditionalShippingCharge":0.0000,"DeliveryDateId":0,"IsTaxExempt":false,"TaxCategoryId":2,"IsTelecommunicationsOrBroadcastingOrElectronicServices":false,"ManageInventoryMethodId":1,"UseMultipleWarehouses":false,"WarehouseId":0,"StockQuantity":10000,"DisplayStockAvailability":true,"DisplayStockQuantity":false,"MinStockQuantity":0,"LowStockActivityId":1,"NotifyAdminForQuantityBelow":1,"BackorderModeId":0,"AllowBackInStockSubscriptions":false,"OrderMinimumQuantity":1,"OrderMaximumQuantity":10000,"AllowedQuantities":null,"AllowAddingOnlyExistingAttributeCombinations":false,"DisableBuyButton":false,"DisableWishlistButton":false,"AvailableForPreOrder":false,"PreOrderAvailabilityStartDateTimeUtc":null,"CallForPrice":false,"Price":1259.0000,"OldPrice":0.0000,"ProductCost":0.0000,"SpecialPrice":null,"SpecialPriceStartDateTimeUtc":null,"SpecialPriceEndDateTimeUtc":null,"CustomerEntersPrice":false,"MinimumCustomerEnteredPrice":0.0000,"MaximumCustomerEnteredPrice":0.0000,"BasepriceEnabled":false,"BasepriceAmount":0.0000,"BasepriceUnitId":0,"BasepriceBaseAmount":0.0000,"BasepriceBaseUnitId":0,"MarkAsNew":false,"MarkAsNewStartDateTimeUtc":null,"MarkAsNewEndDateTimeUtc":null,"HasTierPrices":false,"HasDiscountsApplied":false,"Weight":7.0000,"Length":7.0000,"Width":7.0000,"Height":7.0000,"AvailableStartDateTimeUtc":null,"AvailableEndDateTimeUtc":null,"DisplayOrder":0,"Published":true,"Deleted":true,"CreatedOnUtc":"2016-04-19T11:41:12.177+01:00","UpdatedOnUtc":"2016-04-19T11:41:12.177+01:00","ProductType":"SimpleProduct","BackorderMode":"NoBackorders","DownloadActivationType":"0","GiftCardType":"Virtual","LowStockActivity":"DisableBuyButton","ManageInventoryMethod":"ManageStock","RecurringCyclePeriod":"Days","RentalPricePeriod":"Days","Id":2    } ]}

Addind ]} to the JSON makes it valid and the code in the question should be able to parse it.

将 ]} 添加到 JSON 使其有效，问题中的代码应该能够解析它。