目录
现在的目的是这样的，我想从一串Object类型的字符串，转化成对应的实体类对象。
简单来说就是把这个字符串给一个个独立分开。
我先写出实体类对象和Json的数据，看完再开始解析。
实体类对象
package com.yyt.accountbooks.db.model;
import androidx.room.Entity;
import androidx.room.PrimaryKey;
/**
* @ projectName: AccountBooks
* @ packageName: com.yyt.accountbooks.model
* @ fileName: BillModel
* @ author: zheng
* @ createTime: 2023/1/11 17:32
* @ describe: 账本表对象
*/
@Entity(tableName = "bills")
public class BillModel {
/**
* balance : 0.0
* createTime : 1660880757000
* id : 2
* income : 0.0
* name : 账本一
* params : {}
* pay : 0.0
* remark : 账本备注
* uid : 12
*/
@PrimaryKey
private int id;
private double balance;
private long createTime;
private double income;
private String name;
private double pay;
private String remark;
private int uid;
public double getBalance() {
return balance;
}
public void setBalance(double balance) {
this.balance = balance;
}
public long getCreateTime() {
return createTime;
}
public void setCreateTime(long createTime) {
this.createTime = createTime;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public double getIncome() {
return income;
}
public void setIncome(double income) {
this.income = income;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getPay() {
return pay;
}
public void setPay(double pay) {
this.pay = pay;
}
public String getRemark() {
return remark;
}
public void setRemark(String remark) {
this.remark = remark;
}
public int getUid() {
return uid;
}
public void setUid(int uid) {
this.uid = uid;
}
@Override
public String toString() {
return "BillModel{" +
"balance=" + balance +
", createTime=" + createTime +
", id=" + id +
", income=" + income +
", name='" + name + '\'' +
", pay=" + pay +
", remark='" + remark + '\'' +
", uid=" + uid +
'}';
}
}
Json数据
因为getData()的类型是Object的，获得的是data后面部份的数组，一共有13个数组对象。
string:{"code":0,"data":[{"balance":0.00,"createTime":1660880757000,"id":2,"income":0.00,"name":"账本一","params":{},"pay":0.00,"remark":"账本备注","uid":12},
{"balance":0.00,"createTime":1673076697000,"id":4,"income":0.00,"name":"pppppp","params":{},"pay":0.00,"remark":"pppppp","uid":12},
{"balance":0.00,"createTime":1673077667000,"id":5,"income":0.00,"name":"账本一","params":{},"pay":0.00,"remark":"账本一","uid":12},
{"balance":0.00,"createTime":1673077687000,"id":6,"income":0.00,"name":"账本一","params":{},"pay":0.00,"remark":"账本一","uid":12},
{"balance":0.00,"createTime":1673077696000,"id":7,"income":0.00,"name":"坎坎坷坷看看","params":{},"pay":0.00,"remark":"坎坎坷坷看看","uid":12},
{"balance":0.00,"createTime":1673079793000,"id":8,"income":0.00,"name":"账本一","params":{},"pay":0.00,"remark":"账本一","uid":12},
{"balance":0.00,"createTime":1673080112000,"id":9,"income":0.00,"name":"账本一","params":{},"pay":0.00,"remark":"账本一","uid":12},
{"balance":0.00,"createTime":1673080305000,"id":10,"income":0.00,"name":"哈哈哈哈哈那就","params":{},"pay":0.00,"remark":"哈哈哈哈哈那就","uid":12},
{"balance":0.00,"createTime":1673080319000,"id":11,"income":0.00,"name":"账本一","params":{},"pay":0.00,"remark":"账本一","uid":12},
{"balance":0.00,"createTime":1673080812000,"id":12,"income":0.00,"name":"账本一","params":{},"pay":0.00,"remark":"账本一","uid":12},
{"balance":0.00,"createTime":1673082156000,"id":13,"income":0.00,"name":"账本一","params":{},"pay":0.00,"remark":"账本一","uid":12},
{"balance":0.00,"createTime":1673086473000,"id":14,"income":0.00,"name":"用英语","params":{},"pay":0.00,"remark":"探讨探讨","uid":12},
{"balance":0.00,"createTime":1673088234000,"id":15,"income":0.00,"name":"滚滚滚","params":{},"pay":0.00,"remark":"","uid":12}]}
Gson库解析
错误思路1
直接把Object类型的Json数据直接反序列化为实体类的数组对象。
BillModel[] billModels =gson.fromJson((responseModel.getData().toString())
,BillModel[].class);
解析直接错误，解都解不出来.....
至于为什么？
应该是Object类型的数据直接toString不行。
错误思路2
把Object类型的Json数据先序列化为Json再反序列化为List<Object>对象。
目前的思路：用List把每个对象分出来，再用for循环遍历Gson库解析对象的每个属性。先把这data后面这部分toJson序列化为Json对象，在反序列化为一组一组的List<Object>对象。简单来说就是用Gson库序列化一次和反序列化各一次。
//第一次序列化和反序列化
List<Object> list= mGson.fromJson(mGson.toJson(responseModel.getData()),
List.class);
//定义一个List
List<BillModel> billModelList=new ArrayList<>();
//遍历list，对每一项进行第二次反序列化
for(int i=0;i<list.size();i++){
BillModel model=mGson.fromJson(list.get(i),BillModel.class);
billModelList.add(model);
//查看每一项的数据
KLog.d(list.get(i)+"---------------------------");
}
我的思路结果本应该是这样的一组一组的。
{"balance":0.00,"createTime":1673076697000,
"id":4,"income":0.00,"name":"pppppp","params":{},
"pay":0.00,"remark":"pppppp","uid":12}
结果第二次反序列化打印数据的时候变成了下面这样一组一组！！！这样连Json格式都不是了，还怎么解析！！！
然后编译期间调用实体类的get方法可以，但是结果会出错甚至报错。
至于为什么？
应该是用List第一次解析为Obejct类型会把双引号给去掉，那么此时就不是Json格式了，就不能解析了。
{balance=0.0, createTime=1.660880757E12, id=2.0,
income=0.0, name=小明, params={}, pay=0.0, remark=备注,
uid=12.0}
所以我知道这个办法行不通了，得换一种方法。
正确思路
可以看看用List怎么反序列化的，在我写的下方链接博客里面第四点。
用TypeToken来储存实体类的类型。
List<BillModel> list= mGson.fromJson(mGson.toJson(responseModel.getData()),
new TypeToken<List<BillModel>>(){}.getType());
和错误思路2的区别就是：
- 我直接转化为BillModel实体类，而不是Object类型的了。
- 先序列化一次，再进行一次反序列化即可，不需要第二次遍历每一项list进行反序列化。
if (BuildConfig.DEBUG) {
for(int i=0;i<list.size();i++){
KLog.d(list.get(i).getId()+"---------------------------");
}
}
此时get()方法也能成功获取到数据了。
而且一般整个app用一个Gson对象就行了，就只需要new一个Gson对象，放在全局变量去用就好了，避免资源浪费。
