我有几个包含彼此递归依赖的类,我使用Gson GraphAdapterBuilder将它们序列化为JSON格式,它运行得很好。现在我想将它们反序列化为相同的结构,但无法找到方法。
我做了一个例子:
class ClassA{
public int field;
public ClassB parent;
public ClassA(int f, ClassB p){
field = f;
parent = p;
}
}
class ClassB{
public Vector<ClassA> vector = new Vector<ClassA>();
}
...
ClassB b = new ClassB();
ClassA a1 = new ClassA(1,b);
ClassA a2 = new ClassA(2,b);
ClassA a3 = new ClassA(3,b);
b.vector.add(a1);
b.vector.add(a2);
b.vector.add(a3);
//Serializing object b
GsonBuilder gsonBuilder = new GsonBuilder();
new GraphAdapterBuilder()
.addType(ClassA.class)
.addType(ClassB.class)
.registerOn(gsonBuilder);
Gson gson = gsonBuilder.create();
String json = gson.toJson(b);
输出给了我想要的东西:
{"0x1":{"vector":["0x2","0x3","0x4"]},"0x2":{"field":1,"parent":"0x1"},"0x3":{"field":2,"parent":"0x1"},"0x4":{"field":3,"parent":"0x1"}}
有没有办法将json字符串反序列化为ClassB的对象?
答案 0 :(得分:8)
好的,我找到了解决方案。这很简单。只需使用函数 fromJson 而不是 toJson 使用相同的GraphAdapterBuilder结构。
...
GsonBuilder gsonBuilder = new GsonBuilder();
new GraphAdapterBuilder()
.addType(ClassA.class)
.addType(ClassB.class)
.registerOn(gsonBuilder);
gson = gsonBuilder.create();
СlassB B = gson.fromJson(json,ClassB.class);
System.out.println("B " + B.vector);
for(ClassA classA:B.vector){
System.out.println(classA.field + " " + classA.parent);
}
输出是:
B [ClassA@10178f2b, ClassA@7ab8584d, ClassA@5cad662c]
1 ClassB@7c0f023c
2 ClassB@7c0f023c
3 ClassB@7c0f023c
答案 1 :(得分:-4)
class ClassA{
public int field;
public String parent;
public ClassA(int f, String parent){
this.field = f;
this.parent = parent;
}
}
class ClassB{
public List<String> vector;
}
String str1 = "{\"0x1\":{\"vector\":[\"0x2\",\"0x3\",\"0x4\"]},\"0x2\":{\"field\":1,\"parent\":\"0x1\"},\"0x3\":{\"field\":2,\"parent\":\"0x1\"},\"0x4\":{\"field\":3,\"parent\":\"0x1\"}}";
JsonParser parser = new JsonParser();
JsonObject element = (JsonObject)parser.parse(str1);
JsonElement responseWrapper = element.get("0x1");
Gson gson = new Gson();
ClassB classB =gson.fromJson(responseWrapper,ClassB.class);
System.out.println(classB.vector);
for (String key:classB.vector) {
responseWrapper = element.get( key);
ClassA classA =gson.fromJson(responseWrapper,ClassA.class);
System.out.println(classA.field);
System.out.println(classA.parent);
}