package com.sample.downloadImage;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import org.apache.http.util.ByteArrayBuffer;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.widget.ImageView;
public class downloadImage extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Bitmap bitmap = DownloadImage("http://www.allindiaflorist.com/imgs/arrangemen4.jpg");
ImageView img = (ImageView) findViewById(R.id.img);
img.setImageBitmap(bitmap);
}
private InputStream OpenHttpConnection(String urlString)
throws IOException
{
InputStream in = null;
int response = -1;
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
if (!(conn instanceof HttpURLConnection))
throw new IOException("Not an HTTP connection");
try{
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK) {
in = httpConn.getInputStream();
}
}
catch (Exception ex)
{
throw new IOException("Error connecting");
}
return in;
}
private Bitmap DownloadImage(String URL)
{
Bitmap bitmap = null;
InputStream in = null;
try {
in = OpenHttpConnection(URL);
BufferedInputStream bis = new BufferedInputStream(in, 8190);
ByteArrayBuffer baf = new ByteArrayBuffer(50);
int current = 0;
while ((current = bis.read()) != -1)
{
baf.append((byte)current);
}
byte[] imageData = baf.toByteArray();
bitmap =BitmapFactory.decodeByteArray(imageData, 0, imageData.length);
in.close();
}
catch (IOException e1)
{
e1.printStackTrace();
}
return bitmap;
}
}
wanna retrive images from server , so i tried to post a image in server and retrive through url but it works good for small images and when it comes for big image more than 60kb , could some one give a idea to solve the problem
package com.sample.downloadImage;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import org.apache.http.util.ByteArrayBuffer;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.widget.ImageView;
public class downloadImage extends Activity {
HttpURLConnection httpConn;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Bitmap bitmap = DownloadImage("http://www.allindiaflorist.com/imgs/arrangemen4.jpg");
ImageView img = (ImageView) findViewById(R.id.img);
img.setImageBitmap(bitmap);
}
private InputStream OpenHttpConnection(String urlString)
throws IOException
{
InputStream in = null;
int response = -1;
URL url = new URL(urlString);
URLConnection conn = url.openConnection();
if (!(conn instanceof HttpURLConnection))
throw new IOException("Not an HTTP connection");
try{
httpConn = (HttpURLConnection) conn;
httpConn.setAllowUserInteraction(false);
httpConn.setInstanceFollowRedirects(true);
httpConn.setRequestMethod("GET");
httpConn.connect();
response = httpConn.getResponseCode();
if (response == HttpURLConnection.HTTP_OK) {
in = httpConn.getInputStream();
DownloadImage(urlString);
}
}
catch (Exception ex)
{
throw new IOException("Error connecting");
}
return in;
}
private Bitmap DownloadImage(String URL)
{
Bitmap bitmap = null;
//InputStream is = null;
InputStream in;
try
{
in = httpConn.getInputStream();
BufferedInputStream bis = new BufferedInputStream(in, 3 *1024);
ByteArrayBuffer baf = new ByteArrayBuffer(50);
int current = 0;
while ((current = bis.read()) != -1)
{
baf.append((byte)current);
byte[] imageData = baf.toByteArray();
bitmap =BitmapFactory.decodeByteArray(imageData, 0, imageData.length);
return bitmap;
}
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return bitmap;
}
}
form : Load Large Image from server on Android
it is not uncommon for BitmapFactory.decodeFromStream() to give up and just return null when you connect it directly to the InputStream of a remote connection. Internally, if you did not provide a BufferedInputStream to the method, it will wrap the supplied stream in one with a buffer size of 16384. One option that sometimes works is to pass a BufferedInputStream with a larger buffer size like:
BufferedInputStream bis = new BufferedInputStream(is, 32 * 1024); A more universally effective method is to download the file completely first, and then decode the data like this:
InputStream is = connection.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is, 8190);
ByteArrayBuffer baf = new ByteArrayBuffer(50);
int current = 0;
while ((current = bis.read()) != -1) {
baf.append((byte)current);
}
byte[] imageData = baf.toByteArray();
BitmapFactory.decodeByteArray(imageData, 0, imageData.length);
FYI, the buffer sizes in this example are somewhat arbitrary. As has been said in other answers, it's a fantastic idea not to keep an image that size in memory longer than you have to. You might consider writing it directly to a file and displaying a downsampled version.
Hope that helps!
Look at this page and download the sample code. it will solve your problem
http://developer.android.com/training/displaying-bitmaps/index.html
来源：https://stackoverflow.com/questions/10550349/retriving-image-from-server-to-android-app