在Java中使用Freebase API

Question

我正在开发一个GWT应用程序，以便从Freebase获取查询结果。这是我的EntryPoint类的代码。

package com.google.tracker.client;

import com.freebase.api.Freebase;
import com.freebase.json.JSON;
import com.google.gwt.core.client.EntryPoint;

public class Tracker implements EntryPoint{

    public void onModuleLoad() {
        Freebase freebase = Freebase.getFreebase();
        String query_str = "{" +
                "'id':   null," +
                "'type': '/film/film'," +
                "'name': 'Blade Runner'," +
                "'directed_by': [{" +
                "'id':   null," +
                "'name': null" +
                "}]" +
                "}​".replace('\'', '"');

        JSON query = new JSON(query_str);
        JSON result = freebase.mqlread(query);
        @SuppressWarnings("unused")
        String director = result.get("result").get("directed_by").get(0).get("name").string();
    }
}

我收到以下错误：

[ERROR] Line 10: No source code is available for type com.freebase.api.Freebase; did you forget to inherit a required module?
[ERROR] Line 21: No source code is available for type com.freebase.json.JSON; did you forget to inherit a required module?

造成这些问题的可能原因是什么？

Answer 1

Freebase的API包不是GWT模块，因此无法转换为Javascript。这就是为什么“没有源代码可用”的原因。您需要从服务器调用Freebase并将结果发送到客户端。