Android中解析复杂的JSON数据

前言

在上一遍文章中，介绍了android中解析JSON数据的两种方式，还附上了相应的例子，对于还没有接触过JSON解析的童鞋可以先看上一篇博客。但客户端与服务端的交互中，往往所涉及的JSON数据都比较复杂，不是单纯的JSONObject或者JSONArray，会包含多层嵌套。这篇文章主要目的是使用上篇提到的两种方式解析复杂的JSON数据

解析复杂的JSON数据

1 需要解析的JSON数据：

{
    "response_head":{ "respmenu":"getmerchant", "resptime":"2015-05-16", "respinfo":{ "respcode":"0000", "respdes":"成功" } },
    "response_body":{ "crset":[ { "merchantname":"三火餐厅", "menu":[ { "menuid":"1", "menuname":"酸菜鱼" }, { "menuid":"2", "menuname":"麻婆豆腐" }, { "menuid":"3", "menuname":"酸菜鱼" } ] }, { "merchantname":"粤菜餐厅", "menu":[ { "menuid":"1", "menuname":"炒生菜" }, { "menuid":"2", "menuname":"蒸鱼" }, { "menuid":"3", "menuname":"煎豆腐" } ] }, { "merchantname":"西式餐厅", "menu":[ { "menuid":"1", "menuname":"牛扒" }, { "menuid":"2", "menuname":"罗宋汤" }, { "menuid":"3", "menuname":"三文治" } ] } ] } }

2 构建相应的java对象，用来保存解析的数据

public class Response {

    private Response_head response_head;

    public Response_head getResponse_head() {
        return response_head;
    }

    public void setResponse_head(Response_head response_head) {
        this.response_head = response_head;
    }

    public static class Response_head {
        private String respmenu;
        private String resptime;
        private Respinfo respinfo;

        public String getRespmenu() {
            return respmenu;
        }

        public void setRespmenu(String respmenu) {
            this.respmenu = respmenu;
        }

        public String getResptime() {
            return resptime;
        }

        public void setResptime(String resptime) {
            this.resptime = resptime;
        }

        public Respinfo getRespinfo() {
            return respinfo;
        }

        public void setRespinfo(Respinfo respinfo) {
            this.respinfo = respinfo;
        }

        public static class Respinfo {
            private String respcode;
            private String respdes;

            public String getRespcode() {
                return respcode;
            }

            public void setRespcode(String respcode) {
                this.respcode = respcode;
            }

            public String getRespdes() {
                return respdes;
            }

            public void setRespdes(String respdes) {
                this.respdes = respdes;
            }
        }
    }

    private Response_body response_body;

    public Response_body getResponse_body() {
        return response_body;
    }

    public void setResponse_body(Response_body response_body) {
        this.response_body = response_body;
    }

    public static class Response_body {
        private List<Merchant> crset;

        public List<Merchant> getCrset() {
            return crset;
        }

        public void setCrset(List<Merchant> crset) {
            this.crset = crset;
        }

        public static class Merchant {
            private String merchantname;
            private List<Menu> menu;

            public String getMerchantname() {
                return merchantname;
            }

            public void setMerchantname(String merchantname) {
                this.merchantname = merchantname;
            }

            public List<Menu> getMenu() {
                return menu;
            }

            public void setMenu(List<Menu> menu) {
                this.menu = menu;
            }

            public static class Menu {
                private String menuid;
                private String menuname;

                public String getMenuid() {
                    return menuid;
                }

                public void setMenuid(String menuid) {
                    this.menuid = menuid;
                }

                public String getMenuname() {
                    return menuname;
                }

                public void setMenuname(String menuname) {
                    this.menuname = menuname;
                }
            }
        }
    }
}

3.1 使用android内置的org.json包提供的类解析，并保存在指定的对象中

Response response = new Response();
// 解析response_head
Response_head response_head = new Response_head();
JSONObject jsonObject = new JSONObject(json);
JSONObject responseHead = jsonObject.getJSONObject("response_head");
response_head.setRespmenu(responseHead.getString("respmenu"));
response_head.setResptime(responseHead.getString("resptime"));
Respinfo respInfo = new Respinfo();
JSONObject respinfo = responseHead.getJSONObject("respinfo");
respInfo.setRespcode(respinfo.getString("respcode"));
respInfo.setRespdes(respinfo.getString("respdes"));
response_head.setRespinfo(respInfo);
response.setResponse_head(response_head);
// 解析response_body
Response_body response_body = new Response_body();
JSONObject responseBody = jsonObject.getJSONObject("response_body");
JSONArray jsonArray = responseBody.getJSONArray("crset");
List<Merchant> merchants = new ArrayList<Merchant>();
for (int i = 0; i < jsonArray.length(); i++) {
    // 解析每个merchant
    JSONObject item = jsonArray.getJSONObject(i);
    Merchant merchant = new Merchant();
    merchant.setMerchantname(item.getString("merchantname")); 
    // 解析每个menu
    List<Menu> menus = new ArrayList<Menu>();
    JSONArray array = item.getJSONArray("menu");
    for (int j = 0; j < array.length(); j++) {
        JSONObject menuitem = array.getJSONObject(i);
        Menu menu = new Menu();
        menu.setMenuid(menuitem.getString("menuid"));
        menu.setMenuname(menuitem.getString("menuname"));
        menus.add(menu);
    }
    merchant.setMenu(menus);
    merchants.add(merchant);
}
response_body.setCrset(merchants);
response.setResponse_body(response_body);

3.2 使用google的开源库gson解析，并保存在指定的对象中

Gson gson = new Gson();
Type type = new TypeToken<Response>(){}.getType();
Response response = gson.fromJson(json, type);

结语

1 对比3.1和3.2的解析方式，可以发现使用gson方式解析更加的便捷，也更加的高效
2 不管那种方式，都需要分析好json数据的结构，才能成功的解析。在分析的时候需要耐心，切勿急躁。