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在 Android 上，我使用 google-http-java-client 库从 google place api 解析 json。我按照这些网站google-http-java-client-json 和Android 使用 Google Places and Maps 教程的说明进行操作

我从 google place detail search api 获取 json 内容：

{
   "html_attributions" : [],
   "result" : {
      "address_components" : [
         {
            "long_name" : "10号",
            "short_name" : "10号",
            "types" : [ "street_number" ]
         },
         {
            "long_name" : "East Chang'an Avenue",
            "short_name" : "East Chang'an Avenue",
            "types" : [ "route" ]
         },
         {
            "long_name" : "Dongcheng",
            "short_name" : "Dongcheng",
            "types" : [ "sublocality", "political" ]
         },
         {
            "long_name" : "Beijing",
            "short_name" : "Beijing",
            "types" : [ "locality", "political" ]
         },
         {
            "long_name" : "Beijing",
            "short_name" : "Beijing",
            "types" : [ "administrative_area_level_1", "political" ]
         },
         {
            "long_name" : "CN",
            "short_name" : "CN",
            "types" : [ "country", "political" ]
         }
      ],
      "formatted_address" : "10号 East Chang'an Avenue, Dongcheng, Beijing, China",
      "formatted_phone_number" : "010 6528 8888",
      "geometry" : {
         "location" : {
            "lat" : 39.9074880,
            "lng" : 116.4090440
         }
      },
      "icon" : "http://maps.gstatic.com/mapfiles/place_api/icons/generic_business-71.png",
      "id" : "33c009586d7d2ac1a8d8392c02f03db6c316710a",
      "international_phone_number" : "+86 10 6528 8888",
      "name" : "Shanggong Law Firm",
      "reference" : "CnRvAAAA25ct_IRN2tU_bHsLhfuwQmvrfRR_WEPvFv30GtadCc6Axe6hK3OkL0B1UrLNu7J2scVzn5qylFTf_YOzhf14ba2GcrkCnGkXeobKxJ-DDUCTJOIqVzuvj1BZ5Vb-OxboQeztU3VI9zBgAFGwe8sg3xIQTxsKMMP88wqEtgmQ3ykp7xoUfXj-wTk2kM9v3aQ65wS3bsn5CI8",
      "types" : [ "lawyer", "establishment" ],
      "url" : "https://plus.google.com/113831070987505202557/about?hl=en-US",
      "utc_offset" : 480,
      "vicinity" : "10号 East Chang'an Avenue, Dongcheng, Beijing",
      "website" : "http://www.splf.com.cn/"
   },
   "status" : "OK"
}

这个 json 的 pojo 映射是

public class PoiDetail extends GenericJson implements Serializable{

@Key
public String status;

@Key
public PoiDetailPlace result;

}

public class PoiDetailPlace implements Serializable{

@Key
public String id;

@Key
public String name;

@Key
public String reference;

@Key
public String icon;


@Key
public String vicinity;


@Key
public String formatted_address;
@Key
public String formatted_phone_number;

@Key
public String international_phone_number;


@Key
public String website;
@Key
public Geometry geometry;

public static class Geometry implements Serializable{

    @Key
    public Location location;
}

public static class Location implements Serializable{

    @Key
    public double lat;
    @Key
    public double lng;
}

}

当我编写解析器方法时发生了奇怪的事情。如果我这样写我的代码，没关系。我可以获得详细信息：

public PoiDetail getPoiDetail(String reference) throws IOException{

    try {
        HttpRequestFactory httpRequestFactory = createRequestFactory(HTTP_TRANSPORT);
        HttpRequest request = httpRequestFactory
                .buildGetRequest(new GenericUrl(DETAILS_SEARCH_URL));
        request.getUrl().put("key", API_KEY);
        request.getUrl().put("reference", reference);
        request.getUrl().put("sensor", "false");
        PoiDetail detail = request.execute().parseAs(PoiDetail.class);
        return detail;
    } catch (HttpResponseException e) {
        // TODO Auto-generated catch block
        Log.e("Error in Perform Details", e.getMessage());
        throw e;
    }

}

如果我这样写代码是不行的了解异常是什么：

public PoiDetail getPoiDetail(String reference){

    try {
        HttpRequestFactory httpRequestFactory = createRequestFactory(HTTP_TRANSPORT);
        HttpRequest request = httpRequestFactory
                .buildGetRequest(new GenericUrl(DETAILS_SEARCH_URL));
        request.getUrl().put("key", API_KEY);
        request.getUrl().put("reference", reference);
        request.getUrl().put("sensor", "false");
        PoiDetail detail = request.execute().parseAs(PoiDetail.class);
        return detail;
    } catch (HttpResponseException e) {
        e.printStackTrace();
        return null;
    }catch (IOException e) {
        e.printStackTrace();
        return null;
    }

}

我想知道

是什么导致这两种方法产生不同的结果？

为什么我不应该抓住 IOException ？

这背后的理论是什么？

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0 回答 0