While cycle loop in Java example
While cycle Java basic example with array of strings.
MainClass.java
MainClass.java
public class MainClass {
public static void main(String[] arg) {
String[] arrayOfString = { "Hello", "people", "hello", "world!" };
int i = 0;
while ( i < arrayOfString.length ){
System.out.println(arrayOfString[i]);
i++;
}
}
}
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Špičkový smartphone od Samsungu.
Technické parametry Samsung i9300 Galaxy S III
Rozměry a hmotnost: 137 x 71 x 9 mm, 133 gramů
Datové funkce: GPS modul, WiFi, Bluetooth, NFC, GPRS, EDGE, HSCSD, Hardwarový modem, Infraport
Sítě: pásma GSM 850, 900, 1 800, 1 900 MHz pásma WCDMA (3G) 850, 900, 1 900, 2 100 MHz
Displej: HD Super AMOLED diplej o velikosti 1280x720 4,8 palců
Procesor: čtyřjádrový procesor 1.4 GHz
Uživatelská paměť: 16 MB
paměť RAM 1 024 MB
Operační systém: Android 4.0 ICS
Hudba: MP3
Video: HD rozlišení
Fotoaparát: 8 Mpix
Navigace:
Baterie: Li-Pol, pohotovostní doba 390 hodin
Cena: cca 14.500 korun / léto 2012
Samsung i9300 Galaxy S III obrázek
Technické parametry Samsung i9300 Galaxy S III
Rozměry a hmotnost: 137 x 71 x 9 mm, 133 gramů
Datové funkce: GPS modul, WiFi, Bluetooth, NFC, GPRS, EDGE, HSCSD, Hardwarový modem, Infraport
Sítě: pásma GSM 850, 900, 1 800, 1 900 MHz pásma WCDMA (3G) 850, 900, 1 900, 2 100 MHz
Displej: HD Super AMOLED diplej o velikosti 1280x720 4,8 palců
Procesor: čtyřjádrový procesor 1.4 GHz
Uživatelská paměť: 16 MB
paměť RAM 1 024 MB
Operační systém: Android 4.0 ICS
Hudba: MP3
Video: HD rozlišení
Fotoaparát: 8 Mpix
Navigace:
Baterie: Li-Pol, pohotovostní doba 390 hodin
Cena: cca 14.500 korun / léto 2012
Samsung i9300 Galaxy S III obrázek
MainActivity.java
activity_main.xml
AndroidManifest.xml do not forget INTERNET uses-permission !!!!!!!
package com.asynctaskexample;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.ProgressBar;
import android.widget.TextView;
public class MainActivity extends Activity {
private TextView textView;
private ProgressBar progressBar;
private DownloadWebPageTask mTask = null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView = (TextView) findViewById(R.id.TextView01);
downloadPage();
}
// AsyncTask <TypeOfVarArgParams , ProgressValue , ResultValue> .
private class DownloadWebPageTask extends AsyncTask<String, Integer, String> {
@Override
protected void onPreExecute() {
//textView.setText("Hello !!!");
progressBar = (ProgressBar) findViewById(R.id.progressBar1);
progressBar.setVisibility(View.VISIBLE);
super.onPreExecute();
}
@Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
}
@Override
protected String doInBackground(String... urls) {
String response = "";
for (String url : urls) {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
try {
HttpResponse execute = client.execute(httpGet);
InputStream content = execute.getEntity().getContent();
BufferedReader buffer = new BufferedReader(new InputStreamReader(
content));
String s = "";
while ((s = buffer.readLine()) != null) {
response += s;
}
} catch (Exception e) {
e.printStackTrace();
}
}
return response;
}
@Override
protected void onPostExecute(String result) {
progressBar.setVisibility(View.INVISIBLE);
textView.setText(result);
}
}
private void downloadPage() {
if (mTask != null
&& mTask.getStatus() != DownloadWebPageTask.Status.FINISHED) {
mTask.cancel(true);
}
// execute(String[]) you can put array of links to web pages, or array of Integer[]
// if first param is Integer[] etc.
mTask = (DownloadWebPageTask) new DownloadWebPageTask()
.execute(new String[] { "//android.okhelp.cz/android-market.html",
"//android.okhelp.cz/android-market.html" });
}
@Override
protected void onDestroy() {
super.onDestroy();
if (mTask != null
&& mTask.getStatus() != DownloadWebPageTask.Status.FINISHED) {
mTask.cancel(true);
mTask = null;
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
activity_main.xml
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ProgressBar
android:id="@+id/progressBar1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/TextView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
</LinearLayout>
AndroidManifest.xml do not forget INTERNET uses-permission !!!!!!!
<uses-permission android:name="android.permission.INTERNET" />
Bitmap size calculation:
bmpHeight * bmpWidth
For example:
Resolution of image 1024x860 = 880 640 pixels
If every pixel get 4 byte of memory:
880 640x4= 3 522 560 (3.5MB)
Get bitmap size without allocation of memory:
Get Memory size:
Make your bitmap not bigger as maxMemory size
final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
bmpHeight * bmpWidth
For example:
Resolution of image 1024x860 = 880 640 pixels
If every pixel get 4 byte of memory:
880 640x4= 3 522 560 (3.5MB)
Get bitmap size without allocation of memory:
BitmapFactory.Options options = new BitmapFactory.Options();
// If set to true, the decoder will return null (no bitmap), but the out... fields will still
// be set, allowing the caller to query the bitmap without having to allocate the memory for its pixels.
options.inJustDecodeBounds = true;
BitmapFactory.decodeResource(getResources(), R.drawable.my_image, options);
int imageHeight = options.outHeight; // 1024
int imageWidth = options.outWidth; // 860
String imageType = options.outMimeType; // .jpg .png .gif
Get Memory size:
Make your bitmap not bigger as maxMemory size
final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
float density = getResources().getDisplayMetrics().density;
Debug.MemoryInfo memoryInfo = new Debug.MemoryInfo();
Debug.getMemoryInfo(memoryInfo);
final int maxMemory = (int) (Runtime.getRuntime().maxMemory() / 1024);
final int freeMemory = (int) (Runtime.getRuntime().freeMemory() / 1024);
String memMessage = String.format(
"Free=%d kB,
MaxMem=%d kB,
Memory: Pss=%.2f MB, Private=%.2f MB, Shared=%.2f MB",
freeMemory,
maxMemory,
memoryInfo.getTotalPss() / 1024.0,
memoryInfo.getTotalPrivateDirty() / 1024.0,
memoryInfo.getTotalSharedDirty() / 1024.0);
((TextView)findViewById(R.id.textViewInfo)).setText(memMessage );
How add pair of strings to Hashtable, how get pair key value from Hashtable, how split string, basic Java Android example.
MainClass.java
MainClass.java
import java.util.Enumeration;
import java.util.Hashtable;
public class MainClass {
public static void main(String[] arg) {
// english;germany dictionary
String[] arrayOfString = { "one;eine", "two;zwei", "three;drei" };
Hashtable<String, String> hashTable = new Hashtable<String, String>();
for(String s: arrayOfString){
String[] array = s.split(";");
String sKey ="", sValue="";
if(array.length > 1){
sKey = array[0]; sValue = array[1];
hashTable.put(sKey, sValue);
}
}
Enumeration<String> enumer = hashTable.keys();
while (enumer.hasMoreElements()) {
String keyFromTable = (String) enumer.nextElement();
// get Returns the value to which the specified key is mapped,
// or null if this map contains no mapping for the key
System.out.println(keyFromTable + " = " + hashTable.get(keyFromTable));
}
}
}
/*
two = zwei
one = eine
three = drei
*/
choreographer skipped frames
Create filter with TAG regex to disable Choreographer messages, see code and picture below:
Create filter with TAG regex to disable Choreographer messages, see code and picture below:
^((?!Choreographer).)*$
Editace: 2011-10-04 08:57:30
Počet článků v kategorii: 396
Url:while-cycle-loop-in-java-example