Monday, September 12, 2011

Load HTML coded data (returned from HttpPost) into WebView

In last article "Example of HttpPost on Android", the response returned from HttpPost is HTML coded String, actually it's a webpage.

Load HTML coded data into WebView



It can be loaded into WebView using WebView.loadData(String data, String mimeType, String encoding).

- data: A String of data in the given encoding. The date must be URI-escaped -- '#', '%', '\', '?' should be replaced by %23, %25, %27, %3f respectively.

- mimeType: The MIMEType of the data. i.e. text/html, image/jpeg

- encoding: The encoding of the data. i.e. utf-8, base64



package com.exercise.AndroidHttpPost;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.app.Activity;
import android.os.Bundle;
import android.webkit.WebView;
import android.widget.Toast;

public class AndroidHttpPostActivity extends Activity {

WebView webView;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
webView = (WebView)findViewById(R.id.webview);

BufferedReader bufferedReader = null;
HttpClient httpClient = new DefaultHttpClient();
HttpPost request = new HttpPost("http://search.yahoo.com/search");
List<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("p", "Android"));


try {
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(postParameters);
request.setEntity(entity);

HttpResponse response= httpClient.execute(request);

bufferedReader = new BufferedReader(
new InputStreamReader(response.getEntity().getContent()));
StringBuffer stringBuffer = new StringBuffer("");
String line = "";
String LineSeparator = System.getProperty("line.separator");
while ((line = bufferedReader.readLine()) != null) {
stringBuffer.append(line + LineSeparator);
}
bufferedReader.close();

Toast.makeText(AndroidHttpPostActivity.this,
"Finished",
Toast.LENGTH_LONG).show();

String webData = stringBuffer.toString();

webData = webData.replace("#", "%23");
webData = webData.replace("%", "%25");
webData = webData.replace("\\", "%27");
webData = webData.replace("?", "%3f");

webView.loadData(webData,
"text/html",
"UTF-8");

} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Toast.makeText(AndroidHttpPostActivity.this,
e.toString(),
Toast.LENGTH_LONG).show();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Toast.makeText(AndroidHttpPostActivity.this,
e.toString(),
Toast.LENGTH_LONG).show();
}finally{
if (bufferedReader != null){
try {
bufferedReader.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

}
}




<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello"
/>
<WebView
android:id="@+id/webview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
</LinearLayout>




note: have to modify AndroidManifest.xml to grant permission of "android.permission.INTERNET".



Download the files.


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