long in java example
Android development
long is 64 bit signed type and used when int is not large enough to hold the value.
long je celé číslo 64 bitů -9223372036854775808 +9223372036854775807 a používá se tam, kde typ int není schopen pojmout takovou hodnotu čísla.
long is 64 bit signed type and used when int is not large enough to hold the value.
long je celé číslo 64 bitů -9223372036854775808 +9223372036854775807 a používá se tam, kde typ int není schopen pojmout takovou hodnotu čísla.
// declaration and assignment of value type long
long n = 22337203685477580L;
// print formated value
System.out.printf("The value of x is %d%n", n); // 22337203685477580
System.out.format("%+,8d%n%n", n); // +22 337 203 685 477 580
// declaring more variables in single statement
long lo1 = 12L, lo2 = 56, lo3 = 1455555555589L;
// long range of value
System.out.println(Long.MAX_VALUE); // 9223372036854775807
System.out.println(Long.MIN_VALUE); // -9223372036854775808
// check if a string is a valid number in Java example
// convert string to long Java example
String sLong = "1288888888888888";
long longParse = Long.parseLong(sLong);
// convert strings to numbers
long longFromString = (Long.valueOf(sLong)).longValue();
// long to string in Java example code
Long longObj = new Long(229999999999L);
String str = longObj.toString();
// else
Long longS = 888888888888L;
String strLong = longS.toString();
// compare two long variables
Long longComp1 = 5555L;
if (longComp1.equals(55555555L))
System.out.print("true");
// compares the two specified long values in Java example
int i = longS.compareTo(444444L); // -1 first < second
// 0 first == second
// 1 first > second
System.out.print(i);
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Throws multiple exceptions Java example source code
public void callFc()
throws IndexOutOfBoundsException, ArithmeticException
{
// my code for example:
String[] sArray = {"aa","bb"};
String str = sArray[5]; // IndexOutOfBoundsException
int n = 5 / 0; // ArithmeticException
}
public void someFC (){
try{
callFc();
}
catch(IndexOutOfBoundsException e){
Log.e("TAG", e.toString());
}
catch(ArithmeticException e2){
Log.e2("TAG",e2.toString());
}
}
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 );
Motorola Droid RAZR cena od 12 000 KCZ Kč (únor.2012)
Spokojenost uživatelů nadprůměrná.
Motorola Droid RAZR je chytrý telefon s operačním systémem Android.
Motorola Droid RAZR je (22.února2012) 9. nejpoužívanějším chytrým telefonem u programu Sky Map viz tabulka.
Motorola Droid RAZR photo pic image
Zdroj obrázku: wikipedia
Spokojenost uživatelů nadprůměrná.
Motorola Droid RAZR je chytrý telefon s operačním systémem Android.
Motorola Droid RAZR je (22.února2012) 9. nejpoužívanějším chytrým telefonem u programu Sky Map viz tabulka.
Motorola Droid RAZR photo pic image

Zdroj obrázku: wikipedia
The method onClick(DialogInterface, int) of type new DialogInterface.OnClickListener(){} must override a superclass method.
Try this:
Right click on project
Select Properties
In open dialogue select Java compiler
Set Enable project specific settings
Set Compiler compliance level to 1.6
Try this:
Right click on project
Select Properties
In open dialogue select Java compiler
Set Enable project specific settings
Set Compiler compliance level to 1.6


Editace: 2011-09-26 20:49:35
Počet článků v kategorii: 396
Url:long-in-java-example