我有一个web服务，它发送一个类型化的arraylist，我通过HttpResponse捕获，如下所示：
// create GET request
HttpGet httpGet = new HttpGet("http://localhost:8084/MinecraftRestServer/webresources/Items");
// execute GET request
HttpResponse response = client.execute(httpGet);
// check response
StatusLine statusLine = response.getStatusLine();
int statusCode = statusLine.getStatusCode();
if (statusCode == 200) { // response OK
// retreive response
List<Recipe> recipesList = new ArrayList<Recipe>();
HttpEntity jsonObj = response.getEntity();
//What's next?
从webservice发送的数组如下所示：
recipesList.add(new Item(1, 11, "diamond_ingot", "Diamond ingot",
"0,0,0,0,0,0,0,0,1", "air,diamond_ore"));
recipesList.add(new Item(2, 11, "iron_ingot", "Iron ingot",
"0,0,0,0,0,0,0,0,1", "air,iron_ore"));
以这种格式出现：
[{"recipeCategory":11,"recipeImageID":"diamond_ingot","recipeDescription":"Diamond ingot","recipeLocations":"0,0,0,0,0,0,0,0,1","usedImages":"air,diamond_ore","recipeID":1},{"recipeCategory":11,"recipeImageID":"iron_ingot","recipeDescription":"Iron ingot","recipeLocations":"0,0,0,0,0,0,0,0,1","usedImages":"air,iron_ore","recipeID":2},{"recipeCategory":11,"recipeImageID":"gold_ingot","recipeDescription":"Gold ingot","recipeLocations":"0,0,0,0,0,0,0,0,1","usedImages":"air,gold_ore","recipeID":3},{"recipeCategory":11,"recipeImageID":"diamond_ore","recipeDescription":"Diamond ore","recipeLocations":"0,0,0,0,0,0,0,0,1","usedImages":"air,wooden_pickaxe","recipeID":4},{"recipeCategory":11,"recipeImageID":"iron_ore","recipeDescription":"Iron ore","recipeLocations":"0,0,0,0,0,0,0,0,1","usedImages":"air,wooden_pickaxe","recipeID":5},{"recipeCategory":11,"recipeImageID":"gold_ore","recipeDescription":"Gold ore","recipeLocations":"0,0,0,0,0,0,0,0,1","usedImages":"air,wooden_pickaxe","recipeID":6},{"recipeCategory":2,"recipeImageID":"diamond_boots","recipeDescription":"Boots (Diamond)","recipeLocations":"0,0,0,1,0,1,1,0,1","usedImages":"air,diamond_ingot","recipeID":7},{"recipeCategory":2,"recipeImageID":"gold_boots","recipeDescription":"Boots (Gold)","recipeLocations":"0,0,0,1,0,1,1,0,1","usedImages":"air,gold_ingot","recipeID":8},{"recipeCategory":2,"recipeImageID":"iron_boots","recipeDescription":"Boots (Iron)","recipeLocations":"0,0,0,1,0,1,1,0,1","usedImages":"air,iron_ingot","recipeID":9},{"recipeCategory":2,"recipeImageID":"diamond_leggings","recipeDescription":"Leggings (Diamond)","recipeLocations":"1,1,1,1,0,1,1,0,1","usedImages":"air,diamond_ingot","recipeID":10},{"recipeCategory":2,"recipeImageID":"gold_leggings","recipeDescription":"Leggings (Gold)","recipeLocations":"1,1,1,1,0,1,1,0,1","usedImages":"air,gold_ingot","recipeID":11},{"recipeCategory":2,"recipeImageID":"iron_leggings","recipeDescription":"Leggings (Iron)","recipeLocations":"1,1,1,1,0,1,1,0,1","usedImages":"air,iron_ingot","recipeID":12},{"recipeCategory":2,"recipeImageID":"diamond_chestplate","recipeDescription":"Chestplate (Diamond)","recipeLocations":"1,0,1,1,1,1,1,1,1","usedImages":"air,diamond_ingot","recipeID":13},{"recipeCategory":2,"recipeImageID":"gold_chestplate","recipeDescription":"Chestplate (Gold)","recipeLocations":"1,0,1,1,1,1,1,1,1","usedImages":"air,gold_ingot","recipeID":14},{"recipeCategory":2,"recipeImageID":"iron_chestplate","recipeDescription":"Chestplate (Iron)","recipeLocations":"1,0,1,1,1,1,1,1,1","usedImages":"air,iron_ingot","recipeID":15},{"recipeCategory":2,"recipeImageID":"diamond_helmet","recipeDescription":"Helmet (Diamond)","recipeLocations":"1,1,1,1,0,1,0,0,0","usedImages":"air,diamond_ingot","recipeID":16},{"recipeCategory":2,"recipeImageID":"gold_helmet","recipeDescription":"Helmet (Gold)","recipeLocations":"1,1,1,1,0,1,0,0,0","usedImages":"air,gold_ingot","recipeID":17},{"recipeCategory":2,"recipeImageID":"iron_helmet","recipeDescription":"Helmet
我的问题是，如何将其转换回arraylist（ArrayList<Item>）
客户端应用程序中已存在Item类。
我已经阅读了关于Gson库的示例，但在API 17中进行编译时似乎不再包含它。
最简单的方法是什么？
答案 0 :(得分：1)
如果使用Eclipse，请在项目中从here下载并包含GSON jar。
如果使用Android Studio，请打开build.gradle并将以下内容添加到dependencies块中。或者你可以选择不使用maven，只需将jar放在lib文件夹中即可。
compile 'com.google.code.gson:gson:2.2.4'
接下来，使用GSON构建项目列表。
确保您的Item.java类具有与JSON响应
List<Recipe> recipesList = new ArrayList<Recipe>();
HttpEntity jsonObj = response.getEntity();
String data = EntityUtils.toString(entity);
Log.d("TAG", data);
Gson gson = new GsonBuilder().create();
recipesList = gson.fromJson(data, new TypeToken<List<Item>>() {}.getType());
确保妥善处理例外情况。
答案 1 :(得分：0)
您可以使用Jackson来解析传入的JSON。 （Quick introduction）
如果您已经有一个具有适当属性的类，它可以像这样简单：
public class Items {
private List<Item> items;
// getter+setter
}
ObjectMapper mapper = new ObjectMapper();
Items = mapper.readValue(src, Items.class);
有关详细信息，请参阅this。
答案 2 :(得分：0)
Step 1 : Item obj=new Item;
Step 2: Parse the json formar for example here :
[[Example1][1]
Step 3: while parsing put ur values in obj :
obj.recipeCategory=value1;
Step 4: insret ur obj into arraylist:
arrayList.add(obj);
答案 3 :(得分：0)
我认为您应该使用json-simple库将字符串Json解析为JsonObject并转换为简单数据类型。 例如：
JSONArray arrJson = (JSONArray) parser.parse("String json");
在JSONArray中获取每个元素JSONObject，然后将其解析为简单数据类型：
long recipeCategory = (long) jsonObject.get("recipeCategory");
答案 4 :(得分：0)
您可以像许多用户一样使用Gson，这是使用Gson的RESTfull客户端示例：
public class RestRequest {
Gson gson = new Gson();
public <T> T post(String url, Class<T> clazz,
List<NameValuePair> parameters) {
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(url);
try {
// Add your data
httppost.setEntity(new UrlEncodedFormEntity(parameters));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
StringBuilder json = inputStreamToString(response.getEntity()
.getContent());
T gsonObject = gson.fromJson(json.toString(), clazz);
return gsonObject;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
// Fast Implementation
private StringBuilder inputStreamToString(InputStream is)
throws IOException {
String line = "";
StringBuilder total = new StringBuilder();
// Wrap a BufferedReader around the InputStream
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
// Read response until the end
while ((line = rd.readLine()) != null) {
total.append(line);
}
// Return full string
return total;
}
}
用法将是这样的：
new RestRequest("myserver.com/rest/somewebservice", SomeClass.class, Arrays.asList(new BasicValuePair("postParameter", "someParameterValue")));
在您的情况下，SomeClass.class将Recipe[].class。另请检查this问题以正确处理服务器端错误。
答案 5 :(得分：-1)