将新的Freebase API与Jav​​a客户端一起使用

Question

So far, I've been playing around with the google-api for java so I could get some data from freebase. I've used mqlread successfully. Now, I'd like to try out the text services. Trouble is, I seem to be missing something in the documentation. I can't figure out how to use Freebase.Text.get(List id).

What should I input on the List id parameter? I've tried out the following:

    HttpTransport httpTransport = new NetHttpTransport();
    JsonFactory jsonFactory = new JacksonFactory();

    JsonHttpRequestInitializer requestInitializer = new JsonHttpRequestInitializer() {
        public void initialize(JsonHttpRequest jsonHttpRequest) throws IOException {
            FreebaseRequest freebaseRequest = (FreebaseRequest) jsonHttpRequest;
            freebaseRequest.setPrettyPrint(true);
        }
    };

    Freebase freebase = Freebase.builder(httpTransport, jsonFactory).setJsonHttpRequestInitializer(requestInitializer).build();
    ArrayList<String> list = new ArrayList<String>();

    JSONObject j = new JSONObject();
    j.put("id", "en/bob_dylan");
    list.add(j.toJSONString());
    Freebase.Text.Get text = freebase.text().get(list);
    ContentserviceGet get = text.execute();
    System.out.println(get.toPrettyString());

and

list.add("en/linux_kernel");

Both cases returned 404. Any help is appreciated.

Answer 1

The Google Freebase API for Java is buggy. I found the cause of the problem and entered the following issue: http://code.google.com/p/google-api-java-client/issues/detail?id=493

The intended way of using the API is like this, but it doesn't work:

ContentserviceGet result = freebase.text().get(Arrays.asList("en", "avenue_q")).execute();

Answer 2

You don't have to pass a JSON string through List, id as a simple string type will do the job. Following is the code to get the text:

    HttpTransport httpTransport = new NetHttpTransport();
    JsonFactory jsonFactory = new JacksonFactory();
    HttpRequestInitializer httpRequestInitializer = new HttpRequestInitializer() {
        @Override
        public void initialize(HttpRequest arg0) throws IOException {
            // TODO Auto-generated method stub
        }
    };
    JsonHttpRequestInitializer requestInitializer = new JsonHttpRequestInitializer() {
        public void initialize(JsonHttpRequest jsonHttpRequest) throws IOException {
            FreebaseRequest freebaseRequest = (FreebaseRequest) jsonHttpRequest;
            freebaseRequest.setPrettyPrint(true);
        }
    };
    Freebase.Builder fbb = new  Freebase.Builder(httpTransport, jsonFactory, httpRequestInitializer);
    Freebase freebase = fbb.setJsonHttpRequestInitializer(requestInitializer).build();
    ArrayList<String> list = new ArrayList<String>();
    try {
        list.add("/en/bob_dylan");
        Freebase.Text.Get text = freebase.text().get(list);
        ContentserviceGet get = text.execute();
        System.out.println(get.toPrettyString());
    } catch (Exception e) {
        e.printStackTrace();
    } 

Answer 3

I haven't played with the Java api, but here are two examples that might help you.

API Explorer http://code.google.com/apis/explorer/#_s=freebase&_v=v1-sandbox&_m=text.get&id=en/bob_dylan

Example of batch request (which is a json example) http://wiki.freebase.com/wiki/ApiText#Batch_Requests

Notice that the id field does not start with a / - eg id=en/bob_dylan in the above example.

Alternatively, you can pass it as an array id=["en", "bob_dylan"]

Hope this works.