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Android平台下的原生网络操作可以分为以下几步#xff1a;
创建URL对象#xff1b;通过URL对象获取HttpURLConnection对象#xff1b;通过HttpURLConnection对象设置请求头键值对、网络连接超时时间等#xff1b;通过HttpURLConnection对象的connect()方法建立网…网络操作
Android平台下的原生网络操作可以分为以下几步
创建URL对象通过URL对象获取HttpURLConnection对象通过HttpURLConnection对象设置请求头键值对、网络连接超时时间等通过HttpURLConnection对象的connect()方法建立网络连接通过响应码判断请求是否成功如果成功的话获取输入流对返回的结果进行处理并显示 这里要注意的是网络请求操作不能直接放在ui线程中需要另外开启一个线程去处理网络请求因为网络请求操作是一个耗时的操作。
布局文件
?xml version1.0 encodingutf-8?
LinearLayout xmlns:androidhttp://schemas.android.com/apk/res/androidxmlns:apphttp://schemas.android.com/apk/res-autoxmlns:toolshttp://schemas.android.com/toolsandroid:layout_widthmatch_parentandroid:layout_heightmatch_parenttools:context.MainActivityandroid:orientationverticalButtonandroid:idid/btn_sendgetandroid:layout_widthmatch_parentandroid:layout_heightwrap_contentandroid:text点击发送get请求/Buttonandroid:idid/btn_sendpostandroid:layout_widthmatch_parentandroid:layout_heightwrap_contentandroid:text点击发送post请求/TextViewandroid:idid/tvandroid:layout_widthmatch_parentandroid:layout_heightwrap_contentandroid:scrollbarsverticalandroid:fadeScrollbarsfalse//LinearLayoutGET请求
这里说一下用到的方法的作用 setConnectTimeout设置请求超时时间 setRequestMethod设置请求方法 setRequestProperty设置请求属性 connect()建立网络连接 getResponseCode()获取响应码 try {new Thread(new Runnable() {Overridepublic void run() {try {URL url new URL(http://www.imooc.com/api/teacher?type2page1);HttpURLConnection connection (HttpURLConnection)url.openConnection();connection.setConnectTimeout(30*1000);connection.setRequestMethod(GET);connection.setRequestProperty(Content-Type,application/json);connection.setRequestProperty(Charset,UTF-8);connection.setRequestProperty(Accept-Charset,UTF-8);connection.connect();int responseCode connection.getResponseCode();//如果请求成功if (responseCode HttpURLConnection.HTTP_OK) {//获取输入流InputStream inputStream connection.getInputStream();byte[] bytes new byte[1024];StringBuffer result new StringBuffer();int len 0;while ((len inputStream.read(bytes)) ! -1) {result.append(new String(bytes,0,len));}//不能直接在其它线程更新ui线程可以使用此方法或者使用handlerrunOnUiThread(new Runnable() {Overridepublic void run() {tv.setText(result);}});Log.d(TAG, onClick: result);}}catch (Exception e) {e.printStackTrace();}}}).start();} catch (Exception e) {e.printStackTrace();}POST请求 new Thread(new Runnable() {Overridepublic void run() {try {URL url new URL(http://www.imooc.com/api/teacher?type2page1);HttpURLConnection connection (HttpURLConnection) url.openConnection();connection.setConnectTimeout(30 * 1000);connection.setRequestProperty(Content-Type,application/json);connection.setRequestProperty(Charset,UTF-8);connection.setRequestProperty(Accept-Charset,UTF-8);connection.connect();int responseCode connection.getResponseCode();if (responseCode HttpURLConnection.HTTP_OK) {InputStream inputStream connection.getInputStream();int len 0;byte[] bytes new byte[1024];StringBuffer result new StringBuffer();while ((len inputStream.read(bytes)) ! -1) {result.append(new String(bytes,0,len));}Log.d(TAG, responseCode: responseCode);Log.d(TAG, result: result);runOnUiThread(new Runnable() {Overridepublic void run() {tv.setText(result);}});} else {Log.d(TAG, responseCode: responseCode);}} catch (MalformedURLException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}}).start();解析返回的json数据 public ListLesson JsonToArray(String str) {ListLesson lessonList new ArrayList();try {JSONObject jsonObject new JSONObject(str);JSONArray jsonArray jsonObject.getJSONArray(data);for (int i 0; i jsonArray.length(); i) {JSONObject lesson (JSONObject) jsonArray.get(i);int id lesson.getInt(id);int learner lesson.getInt(learner);String name lesson.getString(name);String picSmall lesson.getString(picSmall);String picBig lesson.getString(picBig);String description lesson.getString(description);Lesson lesson1 new Lesson();lesson1.setId(id);lesson1.setDescription(description);lesson1.setLearner(learner);lesson1.setPicBig(picBig);lesson1.setPicSmall(picSmall);lesson1.setName(name);lessonList.add(lesson1);}} catch (JSONException e) {e.printStackTrace();}return lessonList;}注意事项
Android9.0以后使用http访问网络需要添加配置文件首先在res目录下新建一个xml资源目录然后创建配置文件配置文件的名称必须是neteork_security_config.xml 内容
?xml version1.0 encodingutf-8?
network-security-config!--允许http请求的加载--base-config cleartextTrafficPermitted true/
/network-security-config
