WebView
可以利用其嵌入一个浏览器
1.在布局文件中引入WebView控件
2.获取该控件实例并设置浏览器属性
3.用setWebViewClient使目标网页在WebView显示
4.调用loadUrl方法传入网址并获取权限
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| <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<WebView
android:id="@+id/web_view"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
|
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| public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
WebView webView=(WebView) findViewById(R.id.web_view);
webView.getSettings().setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient());
webView.loadUrl("https://www.baidu.com");
}
}
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| <uses-permission android:name="android.permission.INTERNET"/>
|
使用HTTP协议访问网络
使用HttpURLConnection
GET
1.调用sendRequestWithHttpURLConnection()方法开启子线程,并使用HttpURLConnection发出HTTP请求
2.利用BufferedReader对服务器返回的流进行读取，并将结果传入到showResponse()中
3.在showResponse里通过runOnUiThread将线程切换到主线程,然后更新UI元素（安卓不允许在子线程进行UI操作）
4.获取权限
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| public class MainActivity extends AppCompatActivity implements View.OnClickListener {
TextView responseText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button sendRequest=(Button) findViewById(R.id.send_request);
responseText=(TextView) findViewById(R.id.response_text);
sendRequest.setOnClickListener(this);
}
@Override
public void onClick(View view) {
if(view.getId()==R.id.send_request){
sendRequestWithHttpURLConnection();
}
}
private void sendRequestWithHttpURLConnection() {
new Thread(new Runnable() {
@Override
public void run() {
HttpURLConnection connection=null;
BufferedReader reader=null;
try{
URL url=new URL("https://www.baidu.com");
connection=(HttpURLConnection) url.openConnection();
connection.setRequestMethod("GET");
connection.setConnectTimeout(8000);
connection.setReadTimeout(8000);
InputStream in=connection.getInputStream();
reader=new BufferedReader(new InputStreamReader(in));
StringBuilder response=new StringBuilder();
String line;
while((line= reader.readLine())!=null){
response.append(line);
}
showResponse(response.toString());
}catch (Exception e){
e.printStackTrace();
}finally {
if(reader!=null){
try{
reader.close();
}catch (IOException e){
e.printStackTrace();
}
}
if(connection!=null){
connection.disconnect();
}
}
}
}).start();
}
private void showResponse(final String response){
runOnUiThread(new Runnable() {
@Override
public void run() {
responseText.setText(response);
}
});
}
}
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| <uses-permission android:name="android.permission.INTERNET"/>
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POST
将请求方法改为POST，并在获取输入流之前把要提交数据写出即可。注意每条数据都要以键值对形式存在，数据与数据间用“&”隔开
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| connection.setRequestMethod("POST");
DataOutputStream out=new DataOutputStream(connection.getOutputStream);
out.writeBytes("username=admin & password=123456")
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使用OkHttp
GET
1.添加依赖库
2.获取OkHttpClient实例
3.创建Request对象，发起一条HTTP请求，可以在build之前连缀很多方法来丰富该对象
4.调用newCall()创建一个Call对象，并用execute方法发送请求并获取服务器返回的数据
5.获取返回数据具体内容
6.获取权限
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| implementation ("com.squareup.okhttp3:okhttp:4.12.0")
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| public class MainActivity extends AppCompatActivity implements View.OnClickListener {
TextView responseText;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button sendRequest=(Button) findViewById(R.id.send_request);
responseText=(TextView) findViewById(R.id.response_text);
sendRequest.setOnClickListener(this);
}
@Override
public void onClick(View view) {
sendRequestWithOkHttp();
}
private void sendRequestWithOkHttp() {
new Thread(new Runnable() {
@Override
public void run() {
try {
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url("https://www.baidu.com")
.build();
Response response = client.newCall(request).execute();
String responseData = response.body().string();
showResponse(responseData);
}catch (Exception e){
e.printStackTrace();
}
}
}).start();
}
private void showResponse(final String response){
runOnUiThread(new Runnable() {
@Override
public void run() {
responseText.setText(response);
}
});
}
}
|
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| <uses-permission android:name="android.permission.INTERNET" />
|
POST
1.先构建一个RequestBody对象来存放待提交的参数
2.在Request.Builder()中调用post()方法将RequestBody对象传入
3.接下来操作和GET的一样
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| RequestBody requestBody=new FormBody.Builder()
.add("username","admin")
.add("password","123456")
.build();
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| Request request = new Request.Builder()
.url("https://www.baidu.com")
.post(requestBody)
.build();
|
