编写如下项目：
2 编写Android清单文件
| <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.itheima28.htmldemo" android:versionCode="1" android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8" android:targetSdkVersion="19" /> <uses-permission android:name="android.permission.INTERNET"/>
<application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme" > <activity android:name="com.itheima28.htmldemo.MainActivity" android:label="@string/app_name" > <intent-filter> <action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application>
</manifest> |
3 编写布局文件activity_main.xml
| <LinearLayout xmlns: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" tools:context=".MainActivity" >
<LinearLayout android:layout_width="fill_parent" android:layout_height="wrap_content" android:orientation="horizontal">
<EditText android:id="@+id/et_url" android:layout_width="0dip" android:text="http://www.baidu.com" android:layout_height="wrap_content" android:singleLine="true" android:layout_weight="1"/>
<Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:onClick="getHtml" android:text="GO"/> </LinearLayout>
<ScrollView android:layout_width="fill_parent" android:layout_height="fill_parent">
<TextView android:id="@+id/tv_html" android:layout_width="fill_parent" android:layout_height="fill_parent"/> </ScrollView>
</LinearLayout> |
4 编写Activity的类MainActivity如下：
| package com.itheima28.htmldemo;
import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URL;
import android.app.Activity; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.text.TextUtils; import android.util.Log; import android.view.View; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast;
public class MainActivity extends Activity {
private static final String TAG = "MainActivity"; private static final int SUCCESS = 0; protected static final int ERROR = 1; private EditText etUrl; private TextView tvHtml;
private Handler handler = new Handler() {
@Override public void handleMessage(Message msg) { super.handleMessage(msg); switch (msg.what) { case SUCCESS: tvHtml.setText((String) msg.obj); break; case ERROR: Toast.makeText(MainActivity.this, "访问失败", 0).show(); break; default: break; } }
};
@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);
etUrl = (EditText) findViewById(R.id.et_url); tvHtml = (TextView) findViewById(R.id.tv_html);
}
public void getHtml(View v) { final String url = etUrl.getText().toString();
new Thread(new Runnable() {
@Override public void run() { // 请求网络 String html = getHtmlFromInternet(url);
if(!TextUtils.isEmpty(html)) { // 更新textview的显示了 Message msg = new Message(); msg.what = SUCCESS; msg.obj = html; handler.sendMessage(msg); } else { Message msg = new Message(); msg.what = ERROR; handler.sendMessage(msg); } } }).start(); }
/** * 根据给定的url访问网络, 抓去html代码 * @param url * @return */ protected String getHtmlFromInternet(String url) {
try { URL mURL = new URL(url); HttpURLConnection conn = (HttpURLConnection) mURL.openConnection();
conn.setRequestMethod("GET"); conn.setConnectTimeout(10000); conn.setReadTimeout(5000);
// conn.connect();
int responseCode = conn.getResponseCode();
if(responseCode == 200) { InputStream is = conn.getInputStream(); String html = getStringFromInputStream(is); return html; } else { Log.i(TAG, "访问失败: " + responseCode); } } catch (Exception e) { e.printStackTrace(); } return null; }
/** * 根据流返回一个字符串信息 * @param is * @return * @throws IOException */ private String getStringFromInputStream(InputStream is) throws IOException { ByteArrayOutputStream baos = new ByteArrayOutputStream(); byte[] buffer = new byte[1024]; int len = -1;
while((len = is.read(buffer)) != -1) { baos.write(buffer, 0, len); } is.close();
String html = baos.toString(); // 把流中的数据转换成字符串, 采用的编码是: utf-8
String charset = "utf-8"; if(html.contains("gbk") || html.contains("gb2312") || html.contains("GBK") || html.contains("GB2312")) { // 如果包含gbk, gb2312编码, 就采用gbk编码进行对字符串编码 charset = "gbk"; }
html = new String(baos.toByteArray(), charset); // 对原有的字节数组进行使用处理后的编码名称进行编码 baos.close(); return html; } } |
