廢話不多說,直接開始吧。如果你看到了這一篇文章,但是你對Http協議的基本知識還不夠了解,那你就去看上一篇文章:Android中的Http通信(一)之Http協議基本知識。本篇文章主要介紹的是,根據url讀取網頁html,並且顯示到webview上面。文章很簡單,內容也很簡單,那我爲什麼還要寫呢,目的就是就是爲了瞭解和熟悉URL對象和HttpURLConnection對象的使用。
廢話不多說,直接看佈局吧:
<RelativeLayout 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" >
<WebView
android:id="@+id/webView"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
很簡單,不做任何介紹。
看看Activity中的代碼:
package com.example.http;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.Menu;
import android.view.MenuItem;
import android.webkit.WebView;
/**
* 根據一個URL,通過Http協議,讀取其中的HTML代碼,並顯示到webView上
*
* @author xiaoyf
*
*/
public class MainActivity extends Activity {
private WebView mWebView;
private Handler handler = new Handler();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mWebView = (WebView) findViewById(R.id.webView);
String url = "http://blog.csdn.net/u014544193/article/details/49849843";
new HttpThread(url, mWebView, handler).start();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
也是很easy的,看不懂的話,你還是學學基礎吧
下面是URL和HttpURLConnection應用的核心代碼,也是本篇的核心。
package com.example.http;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import android.os.Handler;
import android.webkit.WebView;
/**
* 爲讀取網絡數據所開闢的子線程
*
* @author xiaoyf
*
*/
public class HttpThread extends Thread {
private final static int CONNECT_OUT_TIME = 5000;
private String url;
private WebView webView;
private Handler handler;
public HttpThread() {
super();
}
public HttpThread(String url, WebView webView, Handler handler) {
super();
this.url = url;
this.webView = webView;
this.handler = handler;
}
@Override
public void run() {
// TODO Auto-generated method stub
try {
// 第一步:創建必要的URL對象
URL httpUrl = new URL(url);
// 第二步:根據URL對象,獲取HttpURLConnection對象
HttpURLConnection connection = (HttpURLConnection) httpUrl
.openConnection();
// 第三步:爲HttpURLConnection對象設置必要的參數(是否允許輸入數據、連接超時時間、請求方式)
connection.setDoInput(true);
connection.setConnectTimeout(CONNECT_OUT_TIME);
connection.setRequestMethod("GET");
// 第四步:開始讀取數據
final StringBuffer buffer = new StringBuffer();
BufferedReader reader = new BufferedReader(new InputStreamReader(
connection.getInputStream()));
String temp = null;
while ((temp = reader.readLine()) != null) {
buffer.append(temp);
}
reader.close();
handler.post(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
webView.loadData(buffer.toString(),
"text/html;charset=utf-8", "utf-8");
}
});
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
流程就是:創建URL對象----->根據URL對象獲取HttpURLConnection對象----->爲HttpURLConnection對象設置必要的參數----->開始讀取數據----->通過handler對象,將html代碼顯示到webview上
項目下載:http://download.csdn.net/detail/u014544193/9337639