OAuth 2.0を使う
ソーシャルなAndroidアプリの作り方

http://api.mixi-platform.com/2/people/@me/@friends

    if (store != null) {
        // token を取得
        token = getValidAccessToken(store);
        if (token != null) {
            // Authorization ヘッダを付与
            authorizationHeader = 
                new BasicHeader("Authorization", "OAuth " + token.accessToken);
            request.addHeader(authorizationHeader);
        }
    }

private PeopleApiResponse parsePeopleFromResponse(String string) {
    PeopleApiResponse res = new PeopleApiResponse();
    ArrayList<MixiPerson> people = new ArrayList<MixiPerson>();
    try {
        // 外側
        JSONObject json = new JSONObject(string);
        res.itemsPerPage = json.getInt("itemsPerPage");
        res.startIndex = json.getInt("startIndex");
        res.totalResults = json.getInt("totalResults");
        
        // 内側(結果のリスト)
        JSONArray entries = json.getJSONArray("entry");
        int count = entries.length();
        for (int i = 0; i < count; i++) {
            JSONObject entry = entries.getJSONObject(i);
            
            MixiPerson person = new MixiPerson();
            person.displayName = entry.getString("displayName");
            person.profileUrl  = entry.getString("profileUrl");
            
            people.add(person);
        }
        res.entry = people;
 
        return res;
    } catch (JSONException e) {
        Log.w(TAG, "something went wrong while parsing json", e);
    }
    return null;
}

    // リストの末尾要素（続きを取得／読み込み中）の構成
    mFooterView = createFooterView();
    mFooterLoadingView = createFooterLoadingView();
 
    // リストの構成
    mListView = (ListView) findViewById(android.R.id.list);
    mListView.setOnItemClickListener(this);
    mListView.addFooterView(mFooterView, null, true);
 
    // リストにセットするアダプタ
    mAdapter = new ArrayAdapter<MixiPerson>(this,
        android.R.layout.simple_list_item_1, android.R.id.text1);
    mListView.setAdapter(mAdapter);

WWW-Authenticate: OAuth error='expired_token'

private static <T> T executeRequestWithRefresh(HttpRequestBase request,ResponseHandler<T> responseHandler, OAuthTokenStore store, boolean isRetry)
throws ClientProtocolException, IOException {
    OAuthToken token = null;
    Header authorizationHeader = null;
    if (store != null) {
        token = getValidAccessToken(store);
        if (token != null) {
            authorizationHeader = 
                new BasicHeader("Authorization", "OAuth " + token.accessToken);
            request.addHeader(authorizationHeader);
        }
    }
    try {
        return executeRequest(request, responseHandler);
    } catch (TokenExpiredException e) {
        if (!e.isRetryable()) {
            Log.w(TAG, "Access token is invalid.");
        } else {
            if (isRetry) {
                Log.e(TAG, "An error occured while trying to refresh the access token.");
            } else {
                // try to refresh
                Log.v(TAG, "Access token has been expired. Trying to refresh.");
                if (authorizationHeader != null)
                    request.removeHeader(authorizationHeader);
                store.setToken(OAuthClient.refreshToken(token.refreshToken));
                return executeRequestWithRefresh(request, responseHandler, store, true);
            }
        }
        throw e;
    }
}

    PeopleApiClient client = new PeopleApiClient(MainActivity.this);
    try {
        return client.getFriends(startIndex, FETCH_COUNT_PER_REQUEST);
    } catch (TokenInvalidException e) {
        Log.w(TAG, "token is no longer valid");
        // トークンが無効になり、リフレッシュもできない場合は、再ログインが必要
        mNeedRelogin = true; 
    } catch (ClientProtocolException e) {
        Log.w(TAG, "request failed", e);
        errorMessage = e.getLocalizedMessage();
    } catch (IOException e) {
        Log.w(TAG, "request failed", e);
        errorMessage = e.getLocalizedMessage();
    }
    return null;