网络判断

主界面：

public class MainActivity extends AppCompatActivity {

private TextView textView;private String path = "http://www.yulin520.com/a2a/forum/allTypeList?sign=376C5BFC22179A1B8FF3A86D4588B29F&pageSize=10&ts=1877785007&forumType=0&page=1";// 将子线程消息传送到主线程private Handler handler = new Handler(){    @Override    public void handleMessage(Message msg) {        super.handleMessage(msg);        switch (msg.what){            case 0:                String json = (String) msg.obj;                Log.i("xxx",json);                Gson gson = new Gson();                break;        }     }};@Overrideprotected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    // /获取资源ID    textView = (TextView) findViewById(R.id.textview);    getServerData();    boolean netWork = NetWorkUtils.isNetWork(this);    Log.i("xxx",netWork+"");    if(!netWork){        Toast.makeText(MainActivity.this, "网络未连接,请设置网络", Toast.LENGTH_SHORT).show();        startActivity(new Intent("android.settings.WIFI_SETTINGS"));// 进入无线网络配置界面        return;    }}private void getServerData() {    new Thread(new Runnable() {        @Override        public void run() {            try {                URL url = new URL(path);                //建立连接对象                HttpURLConnection con = (HttpURLConnection) url.openConnection();                //设置连接超时等待时间                con.setConnectTimeout(5000);                //设置请求方式                con.setRequestMethod("POST");                //判断是否连接成功                if ( con.getResponseCode()==200 ) {                    //获得输入流                    InputStream ins = con.getInputStream();                    //封为工具类                    String json = GetServerDataUtils.getServerData(ins);                    Message message = new Message();                    //给消息加标识                    message.what = 0;                    //把数据给消息                    message.obj = json;                    //通过handler发送消息                    handler.sendMessage(message);                    /*                    抽取                    //定义一个字节数组输出流                    ByteArrayOutputStream stream = new ByteArrayOutputStream();                    //定义字节数组                    byte[] bytes = new byte[1024];                    //定义长度                    int len = 0;                    while ( (len=ins.read(bytes)) !=-1 ){                        stream.write(bytes,0,len);                    }                    ins.close();                    stream.close();                    final String json = stream.toString();                    */                }            } catch (Exception e) {                e.printStackTrace();            }        }    }).start();}

}

抽出的：
public class GetServerDataUtils {
public static String getServerData(InputStream inputStream) {
//定义一个字节数组输出流
ByteArrayOutputStream bos = new ByteArrayOutputStream();
//定义一个字节数组
byte[] buffer = new byte[1024];
//定义长度
int len = 0;
try {
while ((len = inputStream.read(buffer)) != -1) {
bos.write(buffer, 0, len);
}
inputStream.close();
bos.close();
} catch (IOException e) {
e.printStackTrace();
}
String string = bos.toString();
return string;
}
}

网络管理：
public class NetWorkUtils {
public static boolean isNetWork(Context context){
//连接管理权限
ConnectivityManager manager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
//获得当前连接的网络类型
NetworkInfo networkInfo = manager.getActiveNetworkInfo();
if (networkInfo != null){
return true;
}
return false;
}
}