GSON（JSON字符串转换成一个相等的Java对象）

Gson这个Java类库可以把Java对象转换成JSON，也可以把JSON字符串转换成一个相等的Java对象。Gson支持任意复杂Java对象包括没有源代码的对象。
代码例子：
util.Date和sql.Date被转成长整形用于序列化传输 
public class SQLDateSer
ializer implements JsonSerializer<java.sql.Date> {
public JsonElement serialize(java.sql.Date src, Type typeOfSrc,
JsonSerializationContext context) {
return new JsonPrimitive(src.getTime());
}
}
public class UtilDateSerializer implements JsonSerializer<java.util.Date> {
public JsonElement serialize(java.util.Date src, Type typeOfSrc,
JsonSerializationContext context) {
return new JsonPrimitive(src.getTime());
}
}
public class SQLDateDeserializer implements JsonDeserializer<java.sql.Date> {
public java.sql.Date deserialize(JsonElement json, Type typeOfT,
JsonDeserializationContext context) throws JsonParseException {
return new java.sql.Date(json.getAsJsonPrimitive().getAsLong());
}
}
public class UtilDateDeserializer implements JsonDeserializer<java.util.Date> {
public java.util.Date deserialize(JsonElement json, Type typeOfT,
JsonDeserializationContext context) throws JsonParseException {
return new java.util.Date(json.getAsJsonPrimitive().getAsLong());
}
}
序列化反序列化类Worker.class
private String name;
private java.sql.Date dob;
private java.util.Date inTime;
序列化反序列化类Factory.class
private String name;
private Worker worker;
private Set<Worker> workers;
private List<Worker> lws;
序列化反序列化帮助类
public class JsonUtils {
public static String bean2json(Object bean) {
Gson gson = new GsonBuilder().registerTypeAdapter(java.sql.Date.class,
new SQLDateSerializer()).registerTypeAdapter(
java.util.Date.class, new UtilDateSerializer()).setDateFormat(
DateFormat.LONG).setPrettyPrinting().create();
// gson = new Gson();
return gson.toJson(bean);
}
public static <T> T json2bean(String json, Type type) {
Gson g