判断网络是否打开

package com.example.shujvku;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

public class NetStateUtil {
    public static boolean isConn(Context context){
        boolean bisConnFlag = false;
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
        if(networkInfo != null){
            bisConnFlag = connectivityManager.getActiveNetworkInfo().isAvailable();
        }
        return bisConnFlag;

    }
}

MainActivity引用

private void init(int page) {
        String s = urlString + page;
        if(NetStateUtil.isConn(MainActivity.this)){
            new My().execute(s);
            //执行下一步
        }else {
        //没有网络
            Toast.makeText(this, "没有网络", Toast.LENGTH_SHORT).show();
            Dao dao = new Dao(MainActivity.this);
            Cursor query1 = dao.query("per", null, null, null, null, null, null);
            ArrayList<Bean.DataBean> list1 = new ArrayList<Bean.DataBean>();
            if(query1.moveToFirst()){
                do {
                    String title = query1.getString(query1.getColumnIndex("news_title"));
                    Bean.DataBean bean2 = new Bean.DataBean(title);
                    list1.add(bean2);
                }while (query1.moveToNext());
            }
            query1.close();
            list.addAll(list1);

        }

    }