设置网络请求和网络传输

package com.qy.glide;

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

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class HttpUtil {

//注意工具类中使用静态方法
public static boolean isNetworkConnected(Context context) {
    //判断上下文是不是空的
    //为啥要判断啊? 防止context是空的导致 报空指针异常
    if (context != null) {
        //获取连接管理器
        ConnectivityManager mConnectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        //获取网络状态mConnectivityManager.getActiveNetworkInfo();
        NetworkInfo mNetworkInfo = mConnectivityManager.getActiveNetworkInfo();

        if (mNetworkInfo != null) {
            //判断网络是否可用//如果可以用就是 true  不可用就是false
            return mNetworkInfo.isAvailable();
        }
    }
    return false;
}

\
//=====================================================
public static String requestString(String strUrl) {
try {
//把String 变成URL
URL url = new URL(strUrl);
//打开连接
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
//连接超时时间
connection.setConnectTimeout(5000);
//读取超时时间
connection.setReadTimeout(5000);
//设置请求方式(要大写)
connection.setRequestMethod(“GET”);
//判断请求码 HttpURLConnection.HTTP_OK
if (connection.getResponseCode() == 200) {
//获取输入流(输入=>读,输出=>写)
//ctrl+alt+V 补全代码
InputStream stream = connection.getInputStream();
InputStreamReader inputStreamReader = new InputStreamReader(stream, “utf-8”);
BufferedReader reader = new BufferedReader(inputStreamReader);

            //拼接字符串
            StringBuffer buffer = new StringBuffer();
            String str = "";
            //读取字符串
            while ((str = reader.readLine()) != null) {
                //拼接字符串
                buffer.append(str);
            }
            return buffer.toString();
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

}