解析json串 GridView展示并创建数据库添加查看

package animtest.com.example.e531.database_sample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.GridView;
import android.widget.Toast;

import com.google.gson.Gson;
import com.handmark.pulltorefresh.library.PullToRefreshBase;
import com.handmark.pulltorefresh.library.PullToRefreshGridView;

import java.util.ArrayList;
import java.util.List;

import animtest.com.example.e531.database_sample.adapter.GridViewAdapter;
import animtest.com.example.e531.database_sample.bean.DataDataBean;
import animtest.com.example.e531.database_sample.db.JsonDao;
import animtest.com.example.e531.database_sample.utils.MyTask;
import animtest.com.example.e531.database_sample.utils.NetStateUtil;

//MainActitvty

public class MainActivity extends AppCompatActivity {

//页数
private int pageIndex=1;
//操作类型
private int operType=1;
//请求的url地址-此接口得用第三方模拟器测试，否则请求不到数据 why?
private String url="http://gank.io/api/data/Android/10/"+pageIndex;
//集合数据
private List<DataDataBean.ResultsBean> list=new ArrayList<>();
//适配器
private GridViewAdapter gridViewAdapter;
private PullToRefreshGridView pgv;
private JsonDao jsonDao;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

pgv = (PullToRefreshGridView) findViewById(R.id.pgv);

//构造逻辑层
jsonDao = new JsonDao(this);

//初使化组件
initPGV();
//请求数据
requestNetData();

}

private void requestNetData() {
if(NetStateUtil.isConn(this)){
//有网
MyTask task=new MyTask(new MyTask.Icallbacks() {
@Override
public void updateUiByjson(String jsonstr) {
//调用插入方法
jsonDao.insertData(url,jsonstr);

Gson gson=new Gson();
DataDataBean dataDataBean = gson.fromJson(jsonstr, DataDataBean.class);

List<DataDataBean.ResultsBean> results = dataDataBean.getResults();

if(operType==1){
list.clear();
}

list.addAll(results);

setGvAdapter();

//关闭头尾布局
pgv.onRefreshComplete();

}
});
task.execute(url);

}else{
Toast.makeText(this,"当前没有网络，请稍后重试!",Toast.LENGTH_SHORT).show();

//从数据库中查询
String s = jsonDao.queryData(url);
if(!"".equals(s)){
Log.d("zzz","--------从数据库中取得数据------------");
//解析，显示
Gson gson=new Gson();
DataDataBean dataDataBean = gson.fromJson(s, DataDataBean.class);
List<DataDataBean.ResultsBean> results = dataDataBean.getResults();
if(operType==1){
list.clear();
}
list.addAll(results);

//设置适配器
setGvAdapter();

}
//关闭头尾布局--放在最后
pgv.onRefreshComplete();

}
}

public void setGvAdapter(){
if(gridViewAdapter==null){
gridViewAdapter=new GridViewAdapter(this,list);
pgv.setAdapter(gridViewAdapter);
}else {
gridViewAdapter.notifyDataSetChanged();
}
}

private void initPGV() {
pgv.setMode(PullToRefreshBase.Mode.BOTH);
pgv.setOnRefreshListener(new PullToRefreshBase.OnRefreshListener2<GridView>() {
@Override
public void onPullDownToRefresh(PullToRefreshBase<GridView> pullToRefreshBase) {
pageIndex=1;
operType=1;
url="http://gank.io/api/data/Android/10/"+pageIndex;
requestNetData();

}

@Override
public void onPullUpToRefresh(PullToRefreshBase<GridView> pullToRefreshBase) {
pageIndex++;
operType=2;
url="http://gank.io/api/data/Android/10/"+pageIndex;
requestNetData();
}
});
}

}

//外部适配器

package animtest.com.example.e531.database_sample.adapter;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;

import java.util.List;

import animtest.com.example.e531.database_sample.R;
import animtest.com.example.e531.database_sample.bean.DataDataBean;

/**
*
*/
public class GridViewAdapter extends BaseAdapter {
Context context;
List<DataDataBean.ResultsBean> list;

public GridViewAdapter(Context context, List<DataDataBean.ResultsBean> list) {
this.context = context;
this.list = list;
}

@Override
public int getCount() {
return list.size();
}

@Override
public Object getItem(int i) {
return list.get(i);
}

@Override
public long getItemId(int i) {
return i;
}

@Override
public View getView(int i, View view, ViewGroup viewGroup) {
ViewHolder holder;
if (view == null){
view = View.inflate(context, R.layout.item_gridviewlayout,null);
holder = new ViewHolder();

holder.textView = (TextView) view.findViewById(R.id.grid_text);

view.setTag(holder);

}else {
holder = (ViewHolder) view.getTag();
}

holder.textView.setText(list.get(i).getDesc());

//展示图片的时候,,,getImages这个集合有的有,有的为空...所以要进行.判断
// if (list.get(i).getImages() != null){
// //此时加载图片显示
// ImageLoader.getInstance().displayImage(list.get(i).getImages().get(0),holder.imageView, ImageLoaderUtil.getDefaultOption());
// }

return view;
}

private class ViewHolder{
TextView textView;
}

//创建数据库

package animtest.com.example.e531.database_sample.db;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

/**
* Created by jane on 2018/1/15.
*/

public class MyHelper extends SQLiteOpenHelper {
public MyHelper(Context context) {
super(context, "dbcache", null, 1);
}

@Override
public void onCreate(SQLiteDatabase sqLiteDatabase) {
//创建数据表
sqLiteDatabase.execSQL("create table jsontable (id integer primary key autoincrement,url text not null,json text not null)");

}

@Override
public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

}
}

//创建MyTask类

package animtest.com.example.e531.database_sample.utils;

import android.os.AsyncTask;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

/**
* 使用AsyncTask+HttpURLConnection请求数据
* Created by e531 on 2017/10/12.
*/
public class MyTask extends AsyncTask<String,Void,String> {

//申请一个接口类对象
private Icallbacks icallbacks;

//将无参构造设置成私有的，使之在外部不能够调用
private MyTask(){}

//定义有参构造方法
public MyTask(Icallbacks icallbacks) {
this.icallbacks = icallbacks;
}

@Override
protected String doInBackground(String... params) {
String str="";

try {
//使用HttpUrlConnection
URL url=new URL(params[0]);
HttpURLConnection connection=(HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setReadTimeout(5000);
connection.setConnectTimeout(5000);

if(connection.getResponseCode()==200){
InputStream inputStream=connection.getInputStream();
//调用工具类中的静态方法
str=StreamToString.streamToStr(inputStream,"utf-8");
}

} catch (MalformedURLException e) {
e.printStackTrace();

}catch (IOException e){
e.printStackTrace();
}

return str;
}

@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
//解析，封装到bean,更新ui组件
icallbacks.updateUiByjson(s);

}
//定义一个接口
public interface Icallbacks{
/**
* 根据回传的json字符串，解析并更新页面组件
* @param jsonstr
*/
void updateUiByjson(String jsonstr);
}
}

//判断是否有网辅助类

package animtest.com.example.e531.database_sample.utils;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

import animtest.com.example.e531.database_sample.R;

/**
* 得到网络状态的工具类
* Created by e531 on 2017/10/16.
*/
public class NetStateUtil {

/*
* 判断网络连接是否已开
* true 已打开 false 未打开
* */
public static boolean isConn(Context context){
boolean bisConnFlag=false;
ConnectivityManager conManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo network = conManager.getActiveNetworkInfo();
if(network!=null){
bisConnFlag=conManager.getActiveNetworkInfo().isAvailable();
}
return bisConnFlag;
}

/**
* 当判断当前手机没有网络时选择是否打开网络设置
* @param context
*/
public static void showNoNetWorkDlg(final Context context) {
AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setIcon(R.mipmap.ic_launcher) //
.setTitle(R.string.app_name) //
.setMessage("当前无网络").setPositiveButton("设置", new DialogInterface.OnClickListener() {

@Override
public void onClick(DialogInterface dialog, int which) {
// 跳转到系统的网络设置界面
Intent intent = null;
// 先判断当前系统版本
if(android.os.Build.VERSION.SDK_INT > 10){ // 3.0以上
intent = new Intent(android.provider.Settings.ACTION_WIRELESS_SETTINGS);
}else{
intent = new Intent();
intent.setClassName("com.android.settings", "com.android.settings.WirelessSettings");
}
context.startActivity(intent);

}
}).setNegativeButton("知道了", null).show();
}
}

//ToString方法

package animtest.com.example.e531.database_sample.utils;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

/**
* Created by e531 on 2017/10/12.
*/
public class StreamToString {

public static String streamToStr(InputStream inputStream,String chartSet){

StringBuilder builder=new StringBuilder();
try {
BufferedReader br=new BufferedReader(new InputStreamReader(inputStream,chartSet));
String con;
while ((con=br.readLine())!=null){
builder.append(con);
}

br.close();
return builder.toString();

} catch (Exception e) {
e.printStackTrace();
}

return "";
}
}

//创建数据库dao包

package animtest.com.example.e531.database_sample.db;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

/**
* Created by jane on 2018/1/15.
*/

public class JsonDao {
private MyHelper helper;

public JsonDao(Context context) {
helper=new MyHelper(context);
}

//插入数据
public void insertData(String url,String jsonstr){
SQLiteDatabase db=helper.getWritableDatabase();
//先删除，再插入
db.delete("jsontable","url=?",new String[]{jsonstr});

ContentValues values=new ContentValues();
values.put("url",url);
values.put("json",jsonstr);

long rowid = db.insert("jsontable", null, values);
Log.d("zzz","insert-----rowid:"+rowid);
}

/**
* 查询数据
* @param url
* @return
*/
public String queryData(String url){
String json="";
SQLiteDatabase db = helper.getWritableDatabase();
Cursor cursor = db.query("jsontable", null, "url=?", new String[]{url}, null, null, null);
while (cursor.moveToNext()){
json = cursor.getString(cursor.getColumnIndex("json"));
}

return json;

}

}

//第一个Main副本

//item布局

解析json串 GridView展示并创建数据库添加 查看

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解析json串 GridView展示并创建数据库添加查看