今天给大家带来的文章为通过Gson解析json数据并快速保存至数据库的文章。我们要保存是json对象数组,本文中的json数组并非从后台获取,为了演示,直接手动构造。
需要保存到数据库的是手机的品牌和型号。所以,我们需要新建一个bean实体类去保存我们的型号和品牌。在这,我先介绍2个工具,一个是Google官方的Gson解析jar包。
名为Gson.jar,这个百度下载就可以了。另外一个是序列化插件Parcelable。在setting---->>>>plugin----->搜索Parcelable。

。
好了,下面新建我们的bean,取名DeviceModelBean.java。添加属性后,右键选择Generate--->>>Parcelable,然后快速直接序列化。
package com.mero.wyt_register.bean;
import android.os.Parcel;
import android.os.Parcelable;
/**
* Created by chenlei on 2016/10/28.
*/
public class DeviceModelBean implements Parcelable {
public String getBrand() {
return brand;
}
public void setBrand(String brand) {
this.brand = brand;
}
public String getModel() {
return model;
}
public void setModel(String model) {
this.model = model;
}
public String model;//型号
public String brand;//品牌
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(this.model);
dest.writeString(this.brand);
}
protected DeviceModelBean(Parcel in) {
this.model = in.readString();
this.brand = in.readString();
}
public static final Parcelable.Creator<DeviceModelBean> CREATOR = new Parcelable.Creator<DeviceModelBean>() {
@Override
public DeviceModelBean createFromParcel(Parcel source) {
return new DeviceModelBean(source);
}
@Override
public DeviceModelBean[] newArray(int size) {
return new DeviceModelBean[size];
}
};
}
接下来,再看看我们的json字符串的内容。这个字符串是我按照预期目的而构造的。
json字符串内容如下:
String jsonString = "[{\"brand\":\"华为\",\"model\":\"c8818\"},{\"brand\":\"华为\",\"model\":\"Y635\"}," +
"{\"brand\":\"华为\",\"model\":\"Y635-CL00\"},{\"brand\":\"华为\",\"model\":\"P8 Lite\"},{\"brand\":\"华为\",\"model\":\"荣耀X2\"}," +
"{\"brand\":\"华为\",\"model\":\"荣耀Hol-T00\"},{\"brand\":\"华为\",\"model\":\"荣耀3X畅玩版\"}," +
"{\"brand\":\"华为\",\"model\":\"荣耀6\"},{\"brand\":\"华为\",\"model\":\"荣耀4C\"},{\"brand\":\"华为\",\"model\":\"荣耀X3升级版\"}," +
"{\"brand\":\"华为\",\"model\":\"C8816\"},{\"brand\":\"华为\",\"model\":\"C8816D\"},{\"brand\":\"华为\",\"model\":\"Mate 7\"},{\"brand\":\"华为\",\"model\":\"荣耀畅玩4C\"}," +
"{\"brand\":\"华为\",\"model\":\"荣耀7\"},{\"brand\":\"华为\",\"model\":\"荣耀畅玩4C\"},{\"brand\":\"华为\",\"model\":\"荣耀7\"},{\"brand\":\"华为\",\"model\":\"荣耀4A\"}," +
"{\"brand\":\"华为\",\"model\":\"P8\"},{\"brand\":\"华为\",\"model\":\"C2900\"},{\"brand\":\"华为\",\"model\":\"Y320\"}," +
"{\"brand\":\"华为\",\"model\":\"C8815\"},{\"brand\":\"华为\",\"model\":\"Mate\"},{\"brand\":\"华为\",\"model\":\"Y600\"}," +
"{\"brand\":\"华为\",\"model\":\"荣耀6 Plus\"},{\"brand\":\"华为\",\"model\":\"C8817L\"},{\"brand\":\"华为\",\"model\":\"G5000\"}," +
"{\"brand\":\"华为\",\"model\":\"C8817E\"},{\"brand:\":\"华为\",\"model\":\"荣耀6X\"},{\"brand\":\"华为\",\"model\":\"P8 Lite\"}," +
"{\"brand\":\"华为\",\"model\":\"Ascend P8\"},{\"brand\":\"华为\",\"model\":\"荣耀畅玩4X\"},{\"brand\":\"华为\",\"model\":\"G629\"},{\"brand\":\"华为\",\"model\":\"G620\"},{\"brand\":\"华为\",\"model\":\"荣耀X2\"}," +
"{\"brand\":\"华为\",\"model\":\"荣耀3C\"},{\"brand\":\"华为\",\"model\":\"荣耀6 Plus\"},{\"brand\":\"华为\",\"model\":\"C2800\"},{\"brand\":\"华为\",\"model\":\"2601\"},{\"brand\":\"华为\",\"model\":\"G610S\"}," +
"{\"brand\":\"华为\",\"model\":\"Ascend G302D\"},{\"brand\":\"华为\",\"model\":\"Ascend G6\"},{\"brand\":\"华为\",\"model\":\"Ascend G6\"},{\"brand\":\"华为\",\"model\":\"T8950N\"}," +
"{\"brand\":\"华为\",\"model\":\"G610\"},{\"brand\":\"华为\",\"model\":\"C8813DQ\"},{\"brand\":\"华为\",\"model\":\"Y618\"},{\"brand\":\"华为\",\"model\":\"G630\"}," +
"{\"brand\":\"华为\",\"model\":\"G521\"},{\"brand\":\"华为\",\"model\":\"荣耀畅玩4\"}]";
仔细一看,其实就是一些对象数组,每个对象里面有2个元素,一个品牌,一个型号。
接下来,咱们就需要把这些属性全部设置到对象数组里去。
java.lang.reflect.Type type = new TypeToken<List<DeviceModelBean>>(){}.getType();
Gson gson = new Gson();
listDeviceModel = gson.fromJson(jsonString,type);
上面三行就可以将我们的json数组设置到List<DeviceModelBean>数组里去。在这里说明一下上面的用法,Gson可以通过toJson和fromJson方法分别把对象拆分成json数组和把json数组设置到对象集合中。Type是个接口,位于java.lang.reflect包下。formJson通过传入json字符串数组和type的接口对象从而设置到对象中去。
接下来,我们应该编写数据库帮助类和dao来完成数据库的操作。首先,我们先建立一个数据库帮助类DbHelper.java。
public class DbHelper extends SQLiteOpenHelper {
private Context context;
private static final String dbName = "bbzs.db";
public DbHelper(Context context){
super(context,dbName,null,1);
this.context = context;
}
//创建表
@Override
public void onCreate(SQLiteDatabase db) {
String sql1 = "create table if not exists device_model_info(id integer primary key AUTOINCREMENT,model varchar(20),brand varchar(20))";
db.execSQL(sql1);
}
//删除数据库
public void deleteDb(){
context.deleteDatabase(dbName);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
我们可以通过创建DbHelper对象来创建一个数据库的实例和创建表。
然后我们可以写我们的Dao。
dao的完整代码如下:
public class DeviceModelDao {
public static final String TAG = "DeviceModelDao";
Context context;
SQLiteDatabase db;
List<DeviceModelBean> listDeviceModel = null;
public DeviceModelDao(Context context){
this.context = context;
}
//Gson解析数组到对象中去
public List<DeviceModelBean> addObjectToList(){
String jsonString = "[{\"brand\":\"华为\",\"model\":\"c8818\"},{\"brand\":\"华为\",\"model\":\"Y635\"}," +
"{\"brand\":\"华为\",\"model\":\"Y635-CL00\"},{\"brand\":\"华为\",\"model\":\"P8 Lite\"},{\"brand\":\"华为\",\"model\":\"荣耀X2\"}," +
"{\"brand\":\"华为\",\"model\":\"荣耀Hol-T00\"},{\"brand\":\"华为\",\"model\":\"荣耀3X畅玩版\"}," +
"{\"brand\":\"华为\",\"model\":\"荣耀6\"},{\"brand\":\"华为\",\"model\":\"荣耀4C\"},{\"brand\":\"华为\",\"model\":\"荣耀X3升级版\"}," +
"{\"brand\":\"华为\",\"model\":\"C8816\"},{\"brand\":\"华为\",\"model\":\"C8816D\"},{\"brand\":\"华为\",\"model\":\"Mate 7\"},{\"brand\":\"华为\",\"model\":\"荣耀畅玩4C\"}," +
"{\"brand\":\"华为\",\"model\":\"荣耀7\"},{\"brand\":\"华为\",\"model\":\"荣耀畅玩4C\"},{\"brand\":\"华为\",\"model\":\"荣耀7\"},{\"brand\":\"华为\",\"model\":\"荣耀4A\"}," +
"{\"brand\":\"华为\",\"model\":\"P8\"},{\"brand\":\"华为\",\"model\":\"C2900\"},{\"brand\":\"华为\",\"model\":\"Y320\"}," +
"{\"brand\":\"华为\",\"model\":\"C8815\"},{\"brand\":\"华为\",\"model\":\"Mate\"},{\"brand\":\"华为\",\"model\":\"Y600\"}," +
"{\"brand\":\"华为\",\"model\":\"荣耀6 Plus\"},{\"brand\":\"华为\",\"model\":\"C8817L\"},{\"brand\":\"华为\",\"model\":\"G5000\"}," +
"{\"brand\":\"华为\",\"model\":\"C8817E\"},{\"brand:\":\"华为\",\"model\":\"荣耀6X\"},{\"brand\":\"华为\",\"model\":\"P8 Lite\"}," +
"{\"brand\":\"华为\",\"model\":\"Ascend P8\"},{\"brand\":\"华为\",\"model\":\"荣耀畅玩4X\"},{\"brand\":\"华为\",\"model\":\"G629\"},{\"brand\":\"华为\",\"model\":\"G620\"},{\"brand\":\"华为\",\"model\":\"荣耀X2\"}," +
"{\"brand\":\"华为\",\"model\":\"荣耀3C\"},{\"brand\":\"华为\",\"model\":\"荣耀6 Plus\"},{\"brand\":\"华为\",\"model\":\"C2800\"},{\"brand\":\"华为\",\"model\":\"2601\"},{\"brand\":\"华为\",\"model\":\"G610S\"}," +
"{\"brand\":\"华为\",\"model\":\"Ascend G302D\"},{\"brand\":\"华为\",\"model\":\"Ascend G6\"},{\"brand\":\"华为\",\"model\":\"Ascend G6\"},{\"brand\":\"华为\",\"model\":\"T8950N\"}," +
"{\"brand\":\"华为\",\"model\":\"G610\"},{\"brand\":\"华为\",\"model\":\"C8813DQ\"},{\"brand\":\"华为\",\"model\":\"Y618\"},{\"brand\":\"华为\",\"model\":\"G630\"}," +
"{\"brand\":\"华为\",\"model\":\"G521\"},{\"brand\":\"华为\",\"model\":\"荣耀畅玩4\"}]";
try{
java.lang.reflect.Type type = new TypeToken<List<DeviceModelBean>>(){}.getType();
Gson gson = new Gson();
listDeviceModel = gson.fromJson(jsonString,type);
Log.e("TAG",type+"");
for(Iterator iterator = listDeviceModel.iterator();iterator.hasNext();){
DeviceModelBean bean = (DeviceModelBean) iterator.next();
Log.e(TAG,bean.getModel()+bean.getBrand());
}
}catch (Exception e){
Log.e(TAG,"错误:"+e.getMessage());
}
return listDeviceModel;
}
//插入数据到数据库
public void insertModelToDb(List<DeviceModelBean> listDeviceModel){
try{
DbHelper dbHelper = new DbHelper(context);
db = dbHelper.getWritableDatabase();
//开始事务
db.beginTransaction();
Log.e(TAG,listDeviceModel.size()+"");
String sql1 = "insert into device_model_info(id,model,brand) values (?,?,?)";
for(DeviceModelBean f :listDeviceModel){
db.execSQL(sql1,new Object[]{null,f.model,f.brand});
}
}catch (Exception e){
e.printStackTrace();
}finally {
//提交
db.setTransactionSuccessful();
db.endTransaction();
db.close();
}
}
}
创建数据库的脚本为:
create table if not exists device_model_info(id integer primary key AUTOINCREMENT,model varchar(20),brand varchar(20))
执行插入的脚本为:
insert into device_model_info(id,model,brand) values (?,?,?)
这里注意的是第一个为主键id,这个必须得加上integer primary key 才会自动生成。另外,主键必须为null才可以,否则一直
在代码中的用法为:
//创建数据库和表
DbHelper dbHelper = new DbHelper(MyApplication.getMyApplication());
//插入数据到数据库
DeviceModelDao dao = new DeviceModelDao(MyApplication.getMyApplication());
dao.insertModelToDb(dao.addObjectToList());