GSON不正確

Question

handlig初始化靜態列表如果我這樣做：

public static volatile ArrayList<Process> processes = new ArrayList<Process>(){ 
    { 
     add(new Process("News Workflow", "This is the workflow for the news segment", "image")); 
    } 
}; 

，然後這樣的：

String jsonResponse = gson.toJson(processes); 

jsonResponse爲空。

但是，如果我這樣做：

public static volatile ArrayList<Process> processes = new ArrayList<Process>(); 
processes.add(new Process("nam", "description", "image")); 
String jsonResponse = gson.toJson(processes); 

JSON響應是：

[{"name":"nam","description":"description","image":"image"}] 

這是爲什麼？

Answer 1

我不知道Gson的問題是什麼，但是你知道，你在這裏創建ArrayList的子類嗎？

new ArrayList<Process>(){ 
    { 
     add(new Process("News Workflow", "This is the workflow for the news segment", "image")); 
    } 
}; 

您可以檢查通過

System.out.println(processes.getClass().getName()); 

它不會打印java.util.ArrayList。

我想你想使用靜態初始化爲

public static volatile ArrayList<Process> processes = new ArrayList<Process>(); 
static { 
    processes.add(new Process("News Workflow", "This is the workflow for the news segment", "image")); 
}; 

似乎有無名類的問題，同樣的問題在這裏

import com.google.gson.Gson; 
import com.google.gson.GsonBuilder; 

public class GSonAnonymTest { 

    interface Holder { 
     String get(); 
    } 

    static Holder h = new Holder() { 
     String s = "value"; 

     @Override 
     public String get() { 
      return s; 
     } 
    }; 

    public static void main(final String[] args) { 
     final GsonBuilder gb = new GsonBuilder(); 
     final Gson gson = gb.create(); 

     System.out.println("h:" + gson.toJson(h)); 
     System.out.println(h.get()); 
    } 

} 

UPD：看Gson User Guide - Finer Points with Objects，最後點「...匿名類和本地類被忽略，不包括在序列化或反序列化...」