Tela
BaixarActivity.java
package com.baixar;
import android.app.Activity;
import android.app.ProgressDialog;
import android.graphics.Bitmap;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
public class BaixarActivity extends Activity implements OnClickListener, Runnable {
// handler usado para atualizar a view
private Handler handler = new Handler();
private ProgressDialog dialog;
private Bitmap bitmap;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button btBaixar = (Button) findViewById(R.id.btBaixar);
btBaixar.setOnClickListener(this);
}
public void onClick(View arg0) {
dialog = ProgressDialog.show(this, "Exemplo", "Buscando imagem, aguarde...", false, true);
// faz o download numa thread
new Thread(this).start();
}
public void run() {
try {
Http http = new Http();
// link para imagem
bitmap = http.downloadImagem("http://www.market.com.br/img/womansuporte.png");
// precisa do handler para atualizar a view de outra thread
handler.post(new Runnable() {
public void run() {
ImageView imageView1 = (ImageView) findViewById(R.id.imageView1);
Drawable d = new BitmapDrawable(bitmap);
imageView1.setImageDrawable(d);
}
});
} catch (Throwable e) {
Log.e("Erro", e.getMessage(), e);
} finally {
dialog.dismiss();
}
}
}
Http.java
package com.baixar;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
public class Http {
public final String downloadArquivo(String url) {
Log.i("TESTE", "Http.Download: " + url);
try {
URL u = new URL(url);
HttpURLConnection conn = (HttpURLConnection) u.openConnection();
// configura get
conn.setRequestMethod("GET");
conn.setDoInput(true);
conn.setDoOutput(false);
conn.connect();
InputStream in = conn.getInputStream();
// arquivo
String arquivo = readString(in);
conn.disconnect();
return arquivo;
} catch (Exception e) {
Log.e("Erro", e.getMessage());
}
return null;
}
public final Bitmap downloadImagem(String url) {
Log.i("TESTE", "Http.Download: " + url);
try {
URL u = new URL(url);
InputStream in = u.openStream();
Bitmap img = BitmapFactory.decodeStream(in);
in.close();
return img;
} catch (Exception e) {
Log.e("Erro", e.getMessage());
}
return null;
}
private byte[] readBytes(InputStream in) throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
try {
byte[] buffer = new byte[1024];
int len;
while ((len = in.read(buffer)) > 0) {
bos.write(buffer, 0, len);
}
byte[] bytes = bos.toByteArray();
return bytes;
} finally {
bos.close();
in.close();
}
}
private String readString(InputStream in) throws IOException {
byte[] bytes = readBytes(in);
String texto = new String(bytes);
Log.e("Retorno", texto);
return texto;
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<Button
android:id="@+id/btBaixar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Baixar arquivo texto" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
Manifest
<uses-permission android:name="android.permission.INTERNET" />