Gson使用简记

在APP的开发过程中，必不可少的就是网络请求，请求服务器，得到数据，解析数据并加载到控件上，实现了APP的动态数据显示。
在解析数据的方法上也是多种多样的，之前用的都是JsonObject、JsonArray直接解析出来，后来发现用Gson配合Android Studio的 GsonFormat可以更加快速地解析数据。

首先，导入Gson包，在Android Studio的gradle里面添加：

dependencies {    compile 'com.google.code.gson:gson:2.6.2'}

服务器返回值如下：

{    "status": true,     "info": "获取成功",     "results": {        "version": "1",         "title": "测试标题",         "url": "http://www.baidu.com"    }}

然后，用GsonFormat生成Bean文件:

public class WelcomePic {    /**     * status : true     * info : 获取成功     * results : {"version":"1","title":"测试标题","url":"http://www.baidu.com"}     */    private boolean status;    private String info;    /**     * version : 1     * title : 测试标题     * url : http://www.baidu.com     */    private ResultsBean results;    public boolean isStatus() {        return status;    }    public void setStatus(boolean status) {        this.status = status;    }    public String getInfo() {        return info;    }    public void setInfo(String info) {        this.info = info;    }    public ResultsBean getResults() {        return results;    }    public void setResults(ResultsBean results) {        this.results = results;    }    public static class ResultsBean {        private int version;        private String title;        private String url;        public int getVersion() {            return version;        }        public void setVersion(int version) {            this.version = version;        }        public String getTitle() {            return title;        }        public void setTitle(String title) {            this.title = title;        }        public String getUrl() {            return url;        }        public void setUrl(String url) {            this.url = url;        }    }}

获取网路数据用的是Volley：

 /**     * 获取欢迎界面的图片     */    private void getWelcome() {        StringRequest stringRequest = new StringRequest(Baseurl.Welcome, new Response.Listener<String>() {            @Override            public void onResponse(String response) {                Gson gson = new Gson();                WelcomePic welcomePic = gson.fromJson(response,WelcomePic.class);                WelcomePic.ResultsBean resultsBean = welcomePic.getResults();                if (welcomePic.isStatus()){                      ToastUtil.showToast(context,resultsBean.getTitle()+resultsBean.getUrl()+resultsBean.getVersion());                    }                 }            }        }, new Response.ErrorListener() {            @Override            public void onErrorResponse(VolleyError error) {            }        });        queue.add(stringRequest);    }

如果返回的数据包含了列表，原理类似：

{    "status": true,     "info": "获取信息成功",     "results": [        {            "id": "199",             "title": "APP1.1版本更新",             "classid": "1",             "info": "APP1.1版本更新，请更新APP",             "time": "2016-01-18 15:26:54",             "see": "1",             "type": "系统"        },         {            "id": "198",             "title": "欢迎使用APP,             "classid": "2",             "info": "欢迎使用APP，希望你喜欢",             "time": "2016-01-18 15:27:55",             "see": "1",             "type": "通知"        }    ]}

GsonFormat生成的Bean与之前的有点区别,前面的ResultsBean,后面的是List<ResultsBean>：

public class MessageBean {    private boolean status;    private String info;    private List<ResultsBean> results;    public boolean isStatus() {        return status;    }    public void setStatus(boolean status) {        this.status = status;    }    public String getInfo() {        return info;    }    public void setInfo(String info) {        this.info = info;    }    public List<ResultsBean> getResults() {        return results;    }    public void setResults(List<ResultsBean> results) {        this.results = results;    }    public static class ResultsBean {        private String id;        private String title;        private String classid;        private String info;        private String time;        private int see;        private String type;        private String url;        public String getId() {            return id;        }        public void setId(String id) {            this.id = id;        }        public String getTitle() {            return title;        }        public void setTitle(String title) {            this.title = title;        }        public String getClassid() {            return classid;        }        public void setClassid(String classid) {            this.classid = classid;        }        public String getInfo() {            return info;        }        public void setInfo(String info) {            this.info = info;        }        public String getTime() {            return time;        }        public void setTime(String time) {            this.time = time;        }        public int getSee() {            return see;        }        public void setSee(int see) {            this.see = see;        }        public String getType() {            return type;        }        public void setType(String type) {            this.type = type;        }        public String getUrl() {            return url;        }        public void setUrl(String url) {            this.url = url;        }    }}

处理返回的数据：

 private void GetInfolist() {        String path = ""        StringRequest string = new StringRequest(path, new Response.Listener<String>() {            @Override            public void onResponse(String response) {                Gson gson = new Gson();                MessageBean messageBean = gson.fromJson(response, MessageBean.class);                List<MessageBean.ResultsBean> resultsBeen = messageBean.getResults();                if (messageBean.isStatus()) {                    for (int i = 0; i < resultsBeen.size(); i++) {                        if (resultsBeen.get(i).getSee() == 0) {                            resultsBeen.get(i).setSee(R.mipmap.ico_message_issee);                        } else {                            resultsBeen.get(i).setSee(Color.parseColor("#080809"));                        }                        messageBean.setResults(resultsBeen);                    }                    list.add(messageBean);                    mAdapter.notifyDataSetChanged();                }            }        }, new Response.ErrorListener() {            @Override            public void onErrorResponse(VolleyError error) {            }        });        mqueue.add(string);    }