Android JSON 解析庫的使用 - Gson 和 fast-json

JSON(JavaScript Object Notation) 是一種輕量級的數據交換格式。它基於ECMAScript的一個子集。
JSON採用徹底獨立於語言的文本格式，可是也使用了相似於C語言家族的習慣（包括C、C++、C#、Java、JavaScript、Perl、Python等）。
這些特性使JSON成爲理想的數據交換語言。 易於人閱讀和編寫，同時也易於機器解析和生成(網絡傳輸速率)。

 

GSON是由谷歌官方推出的 JSON 與 Java 對象轉化的 Java類庫

fast-json 阿里推出的用於Android平臺的庫，性能很好的Java實現的JSON 解析和生成器，聽說功能強大且速度超越現有的全部庫

 

GSON用法：

1. 解析JSONObject，JSONArray

2. 將JSON實體轉化爲JSON數據

工程導入三個包 fastjson， gson，volley

//從豆瓣網獲取數據, 在 http://www.bejson.com/ 解析查看數據
private void getData() {
    StringRequest request = new StringRequest(url, new Listener<String>() {
        @Override
        public void onResponse(String arg0) {
            Log.i(TAG, arg0); //獲取完成後，在 http://www.bejson.com/ 解析查看數據
            dealData(arg0);
        }
    }, new ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError arg0) {
            // TODO Auto-generated method stub
        }
    });
    new Volley().newRequestQueue(getApplicationContext()).add(request);
}

//處理數據
private void dealData(String result){
    Gson gson = new Gson();
    Book book = gson.fromJson(result, Book.class); // data 轉實體
    Log.i(TAG, book.getTitle() + "; "
            + book.getPublisher() + ";"
            + book.getTags().size() + ";" );
}

 

private String TAG = "CARLOZ";
private String url = "https://api.douban.com/v2/book/1220562";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_jsonparse);
    
    getData(); 
}

Book屬於實體類，詳情，請查看代碼GitHub

 

輸出結果

08-10 21:19:22.321: I/CARLOZ(24911): {"rating":{"max":10,"numRaters":340,"average":"7.0","min":0},"subtitle":"","author":["[日] 片山恭一"],"pubdate":"2005-1","tags":[{"count":133,"name":"片山恭一","title":"片山恭一"},{"count":62,"name":"日本","title":"日本"},{"count":60,"name":"日本文學","title":"日本文學"},{"count":38,"name":"小說","title":"小說"},{"count":32,"name":"滿月之夜白鯨現","title":"滿月之夜白鯨現"},{"count":15,"name":"愛情","title":"愛情"},{"count":8,"name":"純愛","title":"純愛"},{"count":8,"name":"外國文學","title":"外國文學"}],"origin_title":"","image":"http:\/\/img3.douban.com\/mpic\/s1747553.jpg","binding":"平裝","translator":["豫人"],"catalog":"\n      ","pages":"180","images":{"small":"http:\/\/img3.douban.com\/spic\/s1747553.jpg","large":"http:\/\/img3.douban.com\/lpic\/s1747553.jpg","medium":"http:\/\/img3.douban.com\/mpic\/s1747553.jpg"},"alt":"http:\/\/book.douban.com\/subject\/1220562\/","id":"1220562","publisher":"青島出版社","isbn10":"7543632608","isbn13":"9787543632608","title":"滿月之夜白鯨現","url":"http:\/\/api.douban.com\/v2\/book\/1220562","alt_title":"","author_intro":"","summary":"那一年，是聽莫扎特、釣鱸魚和家庭破裂的一年。說到家庭破裂，母親怪本身當初沒有找到好男人，父親則認爲當時是被狐狸精迷住了眼，失常的是母親，但出問題的是父親……。","price":"15.00元"}
08-10 21:19:22.371: I/CARLOZ(24911): 滿月之夜白鯨現; 青島出版社;8;

 

Fast-json

public class FastJsonParseActivity extends Activity {
    
    private String TAG = "CARLOZ";
    private String url = "https://api.douban.com/v2/book/1220562";
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_fast_json_parse);
        
        getData();
    }

    private void getData() {
        StringRequest request = new StringRequest(url, new Listener<String>() {
            @Override
            public void onResponse(String arg0) {
                Log.i(TAG, arg0);
                dealData(arg0);
            }
        }, new ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError arg0) {
                // TODO Auto-generated method stub
            }
        });
        new Volley().newRequestQueue(getApplicationContext()).add(request);
    }
    // JSON data to java object
    private void dealData(String result) {
        Book book = JSON.parseObject(result, Book.class);
        Log.i(TAG, book.getTitle() + "; "
                + book.getPublisher() + ";"
                + book.getTags().size() + ";" );
    }
}

 

運行結果：

08-10 21:43:11.991: I/CARLOZ(28779): {"rating":{"max":10,"numRaters":340,"average":"7.0","min":0},"subtitle":"","author":["[日] 片山恭一"],"pubdate":"2005-1","tags":[{"count":133,"name":"片山恭一","title":"片山恭一"},{"count":62,"name":"日本","title":"日本"},{"count":60,"name":"日本文學","title":"日本文學"},{"count":38,"name":"小說","title":"小說"},{"count":32,"name":"滿月之夜白鯨現","title":"滿月之夜白鯨現"},{"count":15,"name":"愛情","title":"愛情"},{"count":8,"name":"純愛","title":"純愛"},{"count":8,"name":"外國文學","title":"外國文學"}],"origin_title":"","image":"http:\/\/img3.douban.com\/mpic\/s1747553.jpg","binding":"平裝","translator":["豫人"],"catalog":"\n      ","pages":"180","images":{"small":"http:\/\/img3.douban.com\/spic\/s1747553.jpg","large":"http:\/\/img3.douban.com\/lpic\/s1747553.jpg","medium":"http:\/\/img3.douban.com\/mpic\/s1747553.jpg"},"alt":"http:\/\/book.douban.com\/subject\/1220562\/","id":"1220562","publisher":"青島出版社","isbn10":"7543632608","isbn13":"9787543632608","title":"滿月之夜白鯨現","url":"http:\/\/api.douban.com\/v2\/book\/1220562","alt_title":"","author_intro":"","summary":"那一年，是聽莫扎特、釣鱸魚和家庭破裂的一年。說到家庭破裂，母親怪本身當初沒有找到好男人，父親則認爲當時是被狐狸精迷住了眼，失常的是母親，但出問題的是父親……。","price":"15.00元"}
08-10 21:43:12.101: I/CARLOZ(28779): 滿月之夜白鯨現; 青島出版社;8;

// object to JSON data
private void dealData(String result) {
    List<Book> books = JSON.parseObject(result, new TypeReference<List<Book>>(){});
    Book book1 = new Book();
    book1.setTitle("Hello CarloZ");
    Book book2 = new Book();
    book2.setTitle("Hello CarloZ");
    Book book3 = new Book();
    book3.setTitle("Hello CarloZ");
    
    JSON.toJSON(book1); //book1 to JSON data
    JSON.toJSON(books);
}