一般手机都是需要上网的，一般我们的浏览器就是个webview。这里简单实现下下功能，先编写Android的layout布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"android:layout_margin="10dp"android:padding="10dp"tools:context="com.example.jared.webviewstudy.MainActivity"><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"><EditTextandroid:id="@+id/netAddress"android:layout_weight="1"android:layout_width="wrap_content"android:layout_height="wrap_content"/><Buttonandroid:id="@+id/openNetAddress"android:layout_height="wrap_content"android:layout_width="wrap_content"android:layout_weight="0"android:text="Open"android:textAllCaps="false"/></LinearLayout><WebViewandroid:id="@+id/webView"android:layout_width="match_parent"android:layout_height="match_parent" /></LinearLayout>

这里主要是一个EditText用来输入网址，然后一个Button用来打开网页，webView用来呈现网页。编写代码如下：

package com.example.jared.webviewstudy;import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;
import android.widget.EditText;public class MainActivity extends AppCompatActivity {private WebView myWebView;private EditText networkAddr;private Button openNetwork;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);networkAddr = (EditText)findViewById(R.id.netAddress);myWebView = (WebView)findViewById(R.id.webView);openNetwork = (Button)findViewById(R.id.openNetAddress);openNetwork.setOnClickListener(new myOnClickListener());}class myOnClickListener implements View.OnClickListener {@Overridepublic void onClick(View view) {myWebView.getSettings().setJavaScriptEnabled(true);myWebView.setWebViewClient(new WebViewClient() {@Overridepublic boolean shouldOverrideUrlLoading(WebView view, String url) {view.loadUrl(url);return true;}});String networkAddress = networkAddr.getText().toString();myWebView.loadUrl("http://"+networkAddress);}}
}

还有就是权限问题了：

    <uses-permission android:name="android.permission.INTERNET"/>

这里通过setWebViewClient方法，实例化一个WebViewClient，loadurl实现网页的加载。运行看下效果：

这里打开了百度和我的博客的地址，界面略难看，勉强看看了。

一般网络编程都是通过http的，下面就来实现下，首先是HttpURLConnection，这个一般是google官方提供的，还有一个HttpClient，本来有的，现在api23也没有了，需要自己加载进来。

先使用HttpURLConnection和HttpClient吧，新建工程，编写layout代码如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"xmlns:tools="http://schemas.android.com/tools"android:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"android:layout_margin="10dp"tools:context="com.example.jared.httpurlconnectionstudy.MainActivity"><Buttonandroid:id="@+id/sendRequest"android:text="发送请求"android:layout_width="match_parent"android:layout_height="wrap_content" /><ScrollViewandroid:layout_width="match_parent"android:layout_height="match_parent" ><TextViewandroid:id="@+id/response"android:layout_width="match_parent"android:layout_height="wrap_content" /></ScrollView></LinearLayout>

这里主要就是一个按钮获取数据，然后http请求的数据通过ScrollView可以滑动浏览更多的信息，然后把获取到的信息显示在TextView里面。

编写MainActivity，里面有实现了HttpURLConnection和HttpClient：

package com.example.jared.httpurlconnectionstudy;import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;public class MainActivity extends AppCompatActivity {private static final int SHOW_RESPONSE = 1;private Button sendRequestBtn;private TextView responseView;private Handler mHandler = new Handler(){@Overridepublic void handleMessage(Message msg) {switch (msg.what) {case SHOW_RESPONSE:String responseContent = (String)msg.obj;responseView.setText(responseContent);break;}}};@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);ActionBar actionBar = getSupportActionBar();actionBar.hide();setContentView(R.layout.activity_main);responseView = (TextView)findViewById(R.id.response);sendRequestBtn = (Button)findViewById(R.id.sendRequest);sendRequestBtn.setOnClickListener(new myOnClickListener());}private class myOnClickListener implements View.OnClickListener {@Overridepublic void onClick(View view) {switch (view.getId()) {case R.id.sendRequest:String url = "http://www.baidu.com";//sendRequestWithHttpURLConnection(url);sendRequestWithHttpClient(url);break;default:break;}}}private void sendRequestWithHttpClient(final String url) {new Thread(new Runnable() {@Overridepublic void run() {try {HttpClient httpClient = new DefaultHttpClient();HttpGet httpGet = new HttpGet(url);HttpResponse httpResponse = httpClient.execute(httpGet);if(httpResponse.getStatusLine().getStatusCode() == 200) {HttpEntity entity = httpResponse.getEntity();String response = EntityUtils.toString(entity, "utf-8");Message message = new Message();message.what = SHOW_RESPONSE;message.obj = response.toString();mHandler.sendMessage(message);}} catch (Exception e) {e.printStackTrace();}}}).start();}private void sendRequestWithHttpURLConnection(final String url) {new Thread(new Runnable() {@Overridepublic void run() {HttpURLConnection connection = null;try {URL mUrl = new URL(url);connection = (HttpURLConnection)mUrl.openConnection();connection.setRequestMethod("GET");connection.setConnectTimeout(8000);connection.setReadTimeout(8000);InputStream in = connection.getInputStream();BufferedReader reader = new BufferedReader(new InputStreamReader(in));StringBuilder response = new StringBuilder();String line;while((line = reader.readLine()) != null) {response.append(line);}Message message = new Message();message.what = SHOW_RESPONSE;message.obj = response.toString();mHandler.sendMessage(message);} catch (Exception e) {e.printStackTrace();} finally {if (connection != null) {connection.disconnect();}}}}).start();}
}

这里的HttpClient需要在\sdk\platforms\android-23\optional下倒入包到工程目录的libs下面，然后

在build.gradle下面添加

// Apache Http
android {useLibrary 'org.apache.http.legacy'
}
// Header
dependencies {compile "org.apache.httpcomponents:httpcore:4.3.2"
}

这样HttpClient就可以使用了，关于加载别的库，也基本上类似了。

运行效果如下：

关于Http常用的框架有android-async-http，下面就使用下。jar包可以从官网下载：http://loopj.com/android-async-http/。此外还得下载一个httpclient的jar包：http://mvnrepository.com/artifact/cz.msebera.android/httpclient/4.4.1.1。

修改build.gradle如下：

dependencies {compile fileTree(dir: 'libs', include: ['*.jar'])testCompile 'junit:junit:4.12'compile 'com.android.support:appcompat-v7:23.1.1'compile files('libs/android-async-http-1.4.9.jar')compile files('libs/httpclient-4.4.1.1.jar')
}

这里把两个包都放在了libs的目录下。切换到project目录，如下图：

修改MainActivity代码，添加sendRequestWithAsyncHttpClinet方法如下：

private void sendRequestWithAsyncHttpClient(String url) {AsyncHttpClient client = new AsyncHttpClient();client.get(url, new AsyncHttpResponseHandler() {@Overridepublic void onSuccess(int i, Header[] headers, byte[] bytes) {try {String response = new String(bytes, 0, bytes.length, "UTF-8");responseView.setText(response);}catch (Exception e) {e.printStackTrace();}}@Overridepublic void onFailure(int i, Header[] headers, byte[] bytes, Throwable throwable) {}});}

运行可以得到我们一样的效果。AsyncHttpClient很方便地可以使用起来了，比起上面一大堆代码简单了不少。这里通过一个get方法，然后再onSuccess方法中把获取到的数据转为String显示在text就ok了。

关于网络编程的webview和http就基本学到这里了。在此还要谢谢朋友的提醒，光学基础，实际项目会用到很多框架的，需要去熟悉，这里继续慢慢学。