Gson 序列化 POJO 的数组列表的问题

我一直计划使用 simpleXML 来满足我的序列化需求，但是我认为我应该尝试使用 JSON 来学习一些新的东西。

这是我使用 Gson1.7.1来尝试和序列化测试 POJO 的 ArrayList 的代码。

注意: 为了简化代码，我删除了字符串“ s”的 Reader/Writers。

package test;


import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;


import com.google.gson.Gson;


public class TestGsonSerialDeserialList {
public static void main(String[] args) throws IOException{
Gson gson = new Gson();


//Make Serial
String s;
List<TestObject> list = Collections.synchronizedList(new ArrayList<TestObject>() );
list.add(new TestObject());
list.add(new TestObject());


s = gson.toJson(list, ArrayList.class);
System.out.println(s);


//Eat Serial
List<TestObject> list2 = Collections.synchronizedList(gson.fromJson(s, ArrayList.class) );
System.out.println(list2.get(0) );
System.out.println(list2.get(1) );
}
}

下面是我得到的输出:

[{"objectID":1,"i1":12345,"name":"abcdefg","s":["a","b","c"]},{"objectID":2,"i1":12345,"name":"abcdefg","s":["a","b","c"]}]
java.lang.Object@5c74c3aa
java.lang.Object@75d9fd51

在我的菜鸟眼里，这看起来是正确的。只是，DeSerialization 对象列表包含基本对象，而不是我序列化的 TestObject。有没有人能给我解释一下，如果有的话，我该怎么做才能让这事成功？

编辑:

更正测试: 感谢 ColinD

package test;


import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;


import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;


public class TestGsonSerialDeserialList {
public static void main(String[] args) throws IOException{
System.out.println("--- Serialize / Deserialize Started ---");
String fileName = "json\\testList.json";


Gson gson = new Gson();
Type listOfTestObject = new TypeToken<List<TestObject>>(){}.getType();


//Make Serial
Writer osWriter = new OutputStreamWriter( new FileOutputStream(fileName));
List<TestObject> list = Collections.synchronizedList(new ArrayList<TestObject>() );
list.add(new TestObject());
list.add(new TestObject());
list.add(new TestObject());
list.add(new TestObject());
gson.toJson(list, osWriter);
osWriter.close();




//Eat Serial
Reader isReader = new InputStreamReader( new FileInputStream((fileName) ) );
List<TestObject> list2 = Collections.synchronizedList(
(List<TestObject>)gson.fromJson(isReader, listOfTestObject)
);
isReader.close();
System.out.println(list2.get(0) );
System.out.println(list2.get(1) );
System.out.println(list2.get(2) );
System.out.println(list2.get(3) );
System.out.println("--- Serialize / Deserialize Ended ---");
}
}

产出:

--- Serialize / Deserialize Started ---
ID#: 1, i1: 12345, name: abcdefg, s[]: [Ljava.lang.String;@95c083
ID#: 2, i1: 12345, name: abcdefg, s[]: [Ljava.lang.String;@6791d8c1
ID#: 3, i1: 12345, name: abcdefg, s[]: [Ljava.lang.String;@182d9c06
ID#: 4, i1: 12345, name: abcdefg, s[]: [Ljava.lang.String;@5a5e5a50
--- Serialize / Deserialize Ended ---

编辑2:

老实说，我不知道为什么，但是当我用 ArrayList 替换了 TestObject 中嵌入的简单 String []时，它就开始正确地序列化了。

--- Serialize / Deserialize Started ---
ID#: 1, i1: 12345, name: abcdefg, s[]: [a, b, c]
ID#: 2, i1: 12345, name: abcdefg, s[]: [a, b, c]
ID#: 3, i1: 12345, name: abcdefg, s[]: [a, b, c]
ID#: 4, i1: 12345, name: abcdefg, s[]: [a, b, c]
--- Serialize / Deserialize Ended ---