关于使用Gson将hibernate对象序列化到json

Question

public class CustomTypeAdapter implements JsonSerializer<Object> {

@Override
public JsonElement serialize(Object object, Type type, JsonSerializationContext jsc) {
    JsonObject jsonObject = new JsonObject();
    try {
        Map<String, String> properties = BeanUtils.describe(object);
        //org.apache.commons.beanutils
        for (Map.Entry<String, String> entry : properties.entrySet()) {
            jsonObject.addProperty(entry.getKey(),  entry.getValue());
        }
    } catch (Exception ex) {
        ex.printStackTrace();
    }

    return jsonObject;
    }

}

List<ProductHasSize> phsList = s.createCriteria(ProductHasSize.class, "phs")
                .createAlias("phs.product", "product")
                .add(Restrictions.eq("product.id", 1))
                .list();
        GsonBuilder gsonBuilder = new GsonBuilder();
        Gson gson = gsonBuilder.registerTypeAdapter(ProductHasSize.class, new CustomTypeAdapter()).create();
        String element = gson.toJson(phsList);
        response.getWriter().write(element);

[{"product":"com.certus.dbmodel.Product@54554356","size":"com.certus.dbmodel.Size@215a88a","price":"1250.0","qnty":"20","id":"1","class":"class com.certus.dbmodel.ProductHasSize"},{"product":"com.certus.dbmodel.Product@54554356","size":"com.certus.dbmodel.Size@2eab455a","price":"1300.0","qnty":"5","id":"2","class":"class com.certus.dbmodel.ProductHasSize"}]

提前谢了。

Answer 1

beanutils.description没有提供足够的信息。如果所有类型都是原语就好了。

您必须独立地序列化每个属性。对于非基元类型的字段，对其进行序列化。您还必须为实际类型创建适配器，以便访问其属性。

public class CustomTypeAdapter implements JsonSerializer<ProductHasSize> {

@Override
public JsonElement serialize(ProductHasSize phs, Type type, JsonSerializationContext jsc) {

    JsonObject jsonObject = new JsonObject();
//    try {
//        Map<String, String> properties = BeanUtils.describe(object);
//        //org.apache.commons.beanutils
//        for (Map.Entry<String, String> entry : properties.entrySet()) {
//            jsonObject.addProperty(entry.getKey(),  entry.getValue());
//        }
//    } catch (Exception ex) {
//        ex.printStackTrace();
//    }
    jsonObject.addProperty("price", phs.getPrice());
    jsonObject.addProperty("quantity", phs.getQuantity());
    JsonElement jsonProduct = jsc.serialize(phs.getProduct());
    jsonObject.add("product", jsonProduct);
    JsonElement jsonSize = jsc.serialize(phs.getSize());
    jsonObject.add("size", jsonSize);

    return jsonObject;
    }

}

这个页面有一个很好的介绍：http://www.javacreed.com/gson-serialiser-example/