Write simple examples without using Okhttp. Borrow this article: java HttpURLConnection implements simple network requests .
The renderings are as follows:
rxjava2 import:
implementation 'io.reactivex.rxjava2:rxandroid:2.1.1'
implementation 'io.reactivex.rxjava2:rxjava:2.2.8'
- To achieve the effect of the picture above, you must use the Console font, which is available on my nut cloud network disk, and can also be downloaded: download link
- Full code:
package com.exp.cpdemo;
import androidx.appcompat.app.AppCompatActivity;
import android.graphics.Typeface;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import io.reactivex.Observable;
import io.reactivex.ObservableEmitter;
import io.reactivex.ObservableOnSubscribe;
import io.reactivex.Observer;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.disposables.Disposable;
import io.reactivex.schedulers.Schedulers;
public class MainActivity extends AppCompatActivity {
private TextView tvMsg;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tvMsg = findViewById(R.id.tv);
tvMsg.setTextSize(8f); //字体设小点，看着整齐些
setFont(tvMsg);
Observable<String> normalObservable = Observable.create(new ObservableOnSubscribe<String>() {
@Override
public void subscribe(ObservableEmitter<String> observableEmitter) throws Exception {
Log.i("xxx", "开始网络请求,线程名称：" + Thread.currentThread().getName());
observableEmitter.onNext(getTextFromHttp());
}
});
Observer<String> mObserver = new Observer<String>() {
@Override
public void onSubscribe(Disposable disposable) {
}
@Override
public void onNext(String s) {
Log.i("xxx", "网络请求完成，线程名称：" + Thread.currentThread().getName());
tvMsg.setText(s);
}
@Override
public void onError(Throwable throwable) {
}
@Override
public void onComplete() {
Log.d("xxx", "complete");
}
};
normalObservable
.subscribeOn(Schedulers.io())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(mObserver);
}
public void setFont(TextView textView) {
Typeface typeFace2 = Typeface.createFromAsset(getAssets(), "fonts/conso.ttf");
textView.setTypeface(typeFace2);
}
private String getTextFromHttp() {
try {
// 根据地址创建URL对象(网络访问的url)
URL url = new URL("https://publicobject.com/helloworld.txt");
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.setReadTimeout(5000);
urlConnection.setConnectTimeout(5000);
urlConnection.connect();
if (urlConnection.getResponseCode() == 200) {
InputStream is = urlConnection.getInputStream();
ByteArrayOutputStream os = new ByteArrayOutputStream();
int len = 0;
byte buffer[] = new byte[1024];
// 按照缓冲区的大小，循环读取
while ((len = is.read(buffer)) != -1) {
// 根据读取的长度写入到os对象中
os.write(buffer, 0, len);
}
is.close();
// os.close(); //无需关闭
urlConnection.disconnect();
String result = new String(os.toByteArray());
System.out.println(result);
return result;
} else {
System.out.println("------------------连接失败-----------------");
return "";
}
} catch (Exception e) {
e.printStackTrace();
return "";
}
}
}