JSON封装和解析(通过GSON)

JSON封装和解析(通过GSON)

在app的build.gradle中
加入

  // 添加GSON依赖
    compile 'com.google.code.gson:gson:2.8.2'

版本可以在maven库
http://mvnrepository.com/artifact/com.squareup.retrofit2/retrofit
输入gson查看

JSONObject和JsonObject区别

1 JSONObject是java提供的原生类 JsonObject是google提供的类
import org.json.JSONObject
import com.google.gson.JsonObject

2 JSONObjectHashMap保存键值对,JsonObjectLInkedTreeMap 保存键值对

3 对空值处理方式不同
JSONObject: 添加 value 为null,这个键值对会被删掉,读取时会获取不到这个键值对
JsonObject: 添加 value 为null, 可以正常添加 读取时会获取到null的数据

4 toString结果不同
因为JSONObject是用HashMap来保存数据的,所以对它toString的时候可能出现顺序和保存顺序不一致的情况
而JsonObject不存在这个问题

JSON封装

不能直接自己封json String串 因为对于 那种有\r\n的 是不会识别的
而是使用 toJson(Object)的方式去封装Json
这个Object可以是JsonObject或者自己的bean类(但是通过创建bean类的方式会加上了 \ 而有的工具好像是解析不了)

JsonObject jo = new JsonObject();
 jo.addProperty("key", value);
 mGson = new Gson();
 mGson.toJson(jo)
// 要记得加try catch
JSONObject json = new JSONObject();
try { 
          json.put("widgetName", eventRecord.getEntryName());
} catch (Exception ignored) { }

JSON解析

1 创建一个 JavaBean类
在Bean类中,alt+s打开GSONFormat工具
将JSON数据复制到对话框中

注意:这里创建的getXX,setXX方法的XX是与key键完全一样的

2主类中
主类创建GSON对象

 Gson gson = new Gson();

创建
Bean类对象 (如该类名为GetFirstTime)

                                     
 GetFirstTime getTime = gson.fromJson(str2, GetFirstTime.class);
                                     //获得的json字符串,Bean.class

Bean类调用 getXXX()方法即可获取相应的XXX的键值对的值

str_1 = getTime.getFirstTime();

**可能获取的字符串为空 因为 call线程还未执行完,就执行了后面的 因此 要用异步操作
具体可以参考
http://blog.csdn.net/weixin_37577039/article/details/78556296
用rxjava+retrofit2+okhttp+GSON解析
当然也可以用Handler进行消息异步处理
http://blog.csdn.net/weixin_37577039/article/details/78759727

GSON进行JSON数据的嵌套解析:
如这样的数据

{
	"token": "jefawnewfnknafnafnfl1611fawa115g1515165g",
	"success": 1,
	"userInfo": {
		"roleId": 123456,
		"saleFlag": 1,
		"enterpriseId": 614,
		"userId": 704,
		"account": "admin366"
	},
	"msg ": ""
}

创建一个BEAN类,用GSONFormat去自动设置Bean成员和set get方法
在BEAN类的内部,还会有个类
该类声明为public static类型的
并且类中属性与json的数据属性名也一样

具体就不贴出来了 ,直接用GSONFormat对上面的构建就好

重点讲具体怎么解析!

// 外围的,和上面一样 如外围的bean名为Bean0    上面的json string为testJson 
Bean0 bean0 = gson.fromJson(testJson, Bean0.class);
String token = bean0 .getToken();
String success= bean0 .getSuccess();
// 内部类解析
Bean0 .UserInfoBean userInfoBean = bean0 .getUserInfo();
roleId = userInfoBean.getRoleId();

GSON解析嵌套数组形式的JSON格式
如下数据:

{
    "data": {
        "SaleTarget": 0,
        "CollectionTotal": 0,
        "weekSales": [
            {
                "weekName": "01-16",
                "saleTotal": 0
            },
            {
                "weekName": "01-17",
                "saleTotal": 0
            },
            {
                "weekName": "01-18",
                "saleTotal": 0
            },
            {
                "weekName": "01-19",
                "saleTotal": 0
            },
            {
                "weekName": "前天",
                "saleTotal": 0
            },
            {
                "weekName": "昨天",
                "saleTotal": 0
            },
            {
                "weekName": "今天",
                "saleTotal": 0
            }
        ],
        "weekPlans": [
            {
                "weekName": "前天",
                "weekPlanDetail": [
                    {
                        "planSubject": "暂无",
                        "planStatus": "暂无"
                    }
                ]
            },
            {
                "weekName": "昨天",
                "weekPlanDetail": [
                    {
                        "planSubject": "拜访马化腾",
                        "planStatus": "待处理"
                    }
                ]
            },
            {
                "weekName": "今天",
                "weekPlanDetail": [
                    {
                        "planSubject": "暂无",
                        "planStatus": "暂无"
                    }
                ]
            },
            {
                "weekName": "01-23",
                "weekPlanDetail": [
                    {
                        "planSubject": "暂无",
                        "planStatus": "暂无"
                    }
                ]
            },
            {
                "weekName": "01-24",
                "weekPlanDetail": [
                    {
                        "planSubject": "暂无",
                        "planStatus": "暂无"
                    }
                ]
            },
            {
                "weekName": "01-25",
                "weekPlanDetail": [
                    {
                        "planSubject": "暂无",
                        "planStatus": "暂无"
                    }
                ]
            },
            {
                "weekName": "01-26",
                "weekPlanDetail": [
                    {
                        "planSubject": "暂无",
                        "planStatus": "暂无"
                    }
                ]
            }
        ]
    },
    "success": true,
    "msg": ""
}

还是一样的先用GSONFormat对上述数据生成javaBean格式
这时,在父类下,生成的bean中会有下面的内容:


public static class DataBean {	
			  public int getSaleTarget() {
            return SaleTarget;
        }

        public void setSaleTarget(int SaleTarget) {
            this.SaleTarget = SaleTarget;
        }
	// dataBean中又有:
public List<WeekSalesBean> getWeekSales() {
            return weekSales;
        }

        public void setWeekSales(List<WeekSalesBean> weekSales) {
            this.weekSales = weekSales;
        }
 public List<WeekPlansBean> getWeekPlans() {
            return weekPlans;
        }

        public void setWeekPlans(List<WeekPlansBean> weekPlans) {
            this.weekPlans = weekPlans;
        }
        
      // weekSalesBean
 public static class WeekSalesBean {

            private String weekName;
            private int saleTotal;

            public String getWeekName() {
                return weekName;
            }

            public void setWeekName(String weekName) {
                this.weekName = weekName;
            }

            public int getSaleTotal() {
                return saleTotal;
            }

            public void setSaleTotal(int saleTotal) {
                this.saleTotal = saleTotal;
            }
        }  

       // weekPansBean


   public static class WeekPlansBean {

            private String weekName;
            // weekPansBean中又有一个数组类型的WeekPlanDetail
            private List<WeekPlanDetailBean> weekPlanDetail;

            public String getWeekName() {
                return weekName;
            }

            public void setWeekName(String weekName) {
                this.weekName = weekName;
            }

            public List<WeekPlanDetailBean> getWeekPlanDetail() {
                return weekPlanDetail;
            }

            public void setWeekPlanDetail(List<WeekPlanDetailBean> weekPlanDetail) {
                this.weekPlanDetail = weekPlanDetail;
            }
			
			// WeekPlanDetailBean
            public static class WeekPlanDetailBean {
                private String planSubject;
                private String planStatus;

                public String getPlanSubject() {
                    return planSubject;
                }

                public void setPlanSubject(String planSubject) {
                    this.planSubject = planSubject;
                }

                public String getPlanStatus() {
                    return planStatus;
                }

                public void setPlanStatus(String planStatus) {
                    this.planStatus = planStatus;
                }
            }

解析:
第一层:因为这里的第一层不再是简单的key,values对
而是有 data Object 类型
因此 要首先
设外层bean为Bean1 数据为zhanDouTaiData

 Bean1 bean1 = gson.fromJson(zhanDouTaiData, Bean1.class);                 

第二层:

bean1.DataBean dataBean = bean1.getData();
// 就可以获取数据了
       saleTarget=dataBean.getSaleTarget();
        collectionTotal=dataBean.getCollectionTotal();

第三层:
因为data里面还有一个weekSales的数组类型 由上面也可以看出 返回的类型为List<.bean>类型的

// 用一个List<Bean>类型去装载
List<Bean1.DataBean.WeekSalesBean> weekSalesBean = dataBean.getWeekSales();
 // 获取每个List中的属性
     salesTotal0= weekSalesBean.get(0).getSaleTotal();
     salesTotal1= weekSalesBean.get(1).getSaleTotal();
     salesTotal2= weekSalesBean.get(2).getSaleTotal();
     salesTotal3= weekSalesBean.get(3).getSaleTotal();
     salesTotal4= weekSalesBean.get(4).getSaleTotal();
     salesTotal5= weekSalesBean.get(5).getSaleTotal();
     salesTotal6= weekSalesBean.get(6).getSaleTotal();

 List<Bean1.DataBean.WeekPlansBean> weekPlansBeans = dataBean.getWeekPlans();
                    weekPlansBeans.get(0).getWeekName();
                    // 同上 

第四层: 在WeekPlansBean中 又有一个 数组类型的 其实原理和上面是一样的

 List<Bean1.DataBean.WeekPlansBean> weekPlansBeans = dataBean.getWeekPlans();
					//** 获取weekPlansBeans的第0层的数据**
                    List<Bean1.DataBean.WeekPlansBean.WeekPlanDetailBean> weekPlanDetailBeans0 = weekPlansBeans.get(0).getWeekPlanDetail();
                    // 再将weekPlanDetail第0层的数据的PlanSubject和PlanStatus数据获取
                    planSubject0.setText(weekPlanDetailBeans0.get(0).getPlanSubject());
                    planStatus0.setText(weekPlanDetailBeans0.get(0).getPlanStatus());
                    	// 获取weekPlansBeans的第1层的数据
                    List<Bean1.DataBean.WeekPlansBean.WeekPlanDetailBean> weekPlanDetailBeans1 = weekPlansBeans.get(1).getWeekPlanDetail();
                      // 再将weekPlanDetail第0层的数据的PlanSubject和PlanStatus数据获取
                    planSubject1.setText(weekPlanDetailBeans1.get(0).getPlanSubject());
                    planStatus1.setText(weekPlanDetailBeans1.get(0).getPlanStatus());
                    // 同上
                    List<Bean1.DataBean.WeekPlansBean.WeekPlanDetailBean> weekPlanDetailBeans2 = weekPlansBeans.get(2).getWeekPlanDetail();
                    planSubject2.setText(weekPlanDetailBeans2.get(0).getPlanSubject());
                    planStatus2.setText(weekPlanDetailBeans2.get(0).getPlanStatus());
                    List<Bean1.DataBean.WeekPlansBean.WeekPlanDetailBean> weekPlanDetailBeans3 = weekPlansBeans.get(3).getWeekPlanDetail();
                    planSubject3.setText(weekPlanDetailBeans3.get(0).getPlanSubject());
                    planStatus3.setText(weekPlanDetailBeans3.get(0).getPlanStatus());
                    List<Bean1.DataBean.WeekPlansBean.WeekPlanDetailBean> weekPlanDetailBeans4 = weekPlansBeans.get(4).getWeekPlanDetail();
                    planSubject4.setText(weekPlanDetailBeans4.get(0).getPlanSubject());
                    planStatus4.setText(weekPlanDetailBeans4.get(0).getPlanStatus());
                    List<Bean1.DataBean.WeekPlansBean.WeekPlanDetailBean> weekPlanDetailBeans5 = weekPlansBeans.get(5).getWeekPlanDetail();
                    planSubject5.setText(weekPlanDetailBeans5.get(0).getPlanSubject());
                    planStatus5.setText(weekPlanDetailBeans5.get(0).getPlanStatus());
                    List<Bean1.DataBean.WeekPlansBean.WeekPlanDetailBean> weekPlanDetailBeans6 = weekPlansBeans.get(6).getWeekPlanDetail();
                    planSubject6.setText(weekPlanDetailBeans6.get(0).getPlanSubject());
                    planStatus6.setText(weekPlanDetailBeans6.get(0).getPlanStatus());

GSON解析 第一层为数组形式的JSON数据
如:

[
    {
        "pkey": 1,
        "cities": [
            {
                "pkey": 106,
                "name": "揭阳"
            },
            {
                "pkey": 308,
                "name": "梅州"
            }
            ],
        "name": "广东"
    },
    {
        "pkey": 2,
        "cities": [
            {
                "pkey": 1452,
                "name": "北京"
            }
        ],
        "name": "北京"
    },
    {
        "pkey": 45,
        "cities": [
            {
                "pkey": 1560,
                "name": "拉萨"
            }
        ],
        "name": "西藏"
    }
]

首先也是用 GSONFormat创建Bean类
这里不展示
**解析: **

// 解析 数据
        Gson gson = new Gson();
        List<ProvinceCityBean> provinceCityBean = gson.fromJson(stringBuilder.toString(),
        new TypeToken<List<ProvinceCityBean>>(){}.getType());
        List<String> citiesList = new ArrayList<>();
        for(int i=0; i<provinceCityBean.size();i++){
            options1Items.add(provinceCityBean.get(i).getName());
            List<ProvinceCityBean.CitiesBean> citiesBean = provinceCityBean.get(i).getCities();
            for(int j=0;j<citiesBean.size();j++) {
                // 市
                citiesList.add(citiesBean.get(j).getName());
            }
        }

GSON的序列化
@SerializedName

比如你的json数据为
int a
string b
可以通过序列化将名字更改 方便使用
1 首先,Bean类继承接口

 implements Serializable

2 序列化

@SerializedName("a") public int number;
@SerializedName("b") public String userName;

就可以通过number,和userName去使用了

    原文作者:5ingwings
    原文地址: https://blog.csdn.net/weixin_37577039/article/details/78546482
    本文转自网络文章,转载此文章仅为分享知识,如有侵权,请联系博主进行删除。
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