File open read to StringBuilder close Java example
BufferedReader , FileReader, StringBuilder , readLine, close Java example
Android example
Java example
Android example
String MYFILE = "my_file";
FileInputStream fis = openFileInput(MYFILE);
int c; String sText = "";
while((c=fis.read())!=-1)
{
sText += (char)c; // convert int to char
}
fis.close();
Java example
try {
BufferedReader in = new BufferedReader(new FileReader("myfile.txt"));
StringBuilder strBuilder = new StringBuilder();
String str;
while ((str = in.readLine()) != null) {
strBuilder.append(str);
}
in.close();
} catch (IOException e) {
e.toString();
}
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Map TreeMap key value pair, Map sort by key, Iterator for Map Java Android example.
MainClass.java
MainClass.java
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
public class MainClass {
public static void main(String[] arg) {
// english;germany dictionary
String[] arrayOfString = { "one;eine", "two;zwei", "three;drei", "four;vier" };
Map<String, String> map = new TreeMap<String, String>();
for(String s: arrayOfString){
String[] array = s.split(";");
String sKey ="", sValue="";
if(array.length > 1){
sKey = array[0]; sValue = array[1];
map.put(sKey, sValue);
}
}
List sortedByKeys=new ArrayList(map.keySet());
Collections.sort(sortedByKeys);
// iterate map
Set references = map.keySet();
Iterator it = references.iterator();
while (it.hasNext()) {
String key = (String) it.next();
String value = map.get(key);
System.out.println(key + " = " + value);
}
// or other example how iterate map
TreeSet<String> keys = new TreeSet<String>(map.keySet());
for (String key : keys) {
String value = map.get(key);
System.out.println(key + " = " + value);
}
// check if key exists
// if( map.containsKey("two")){
// System.out.print("two = " + map.get("two"));
// }
}
}
/*
four = vier
one = eine
three = drei
two = zwei
*/
Admob testing on emulator issue.
Android Eclipse code warning:
setTesting(boolean) from the type AdRequest is deprecated
Solution:
adRequest.addTestDevice(AdRequest.TEST_EMULATOR);
Android Eclipse code warning:
setTesting(boolean) from the type AdRequest is deprecated
Solution:
adRequest.addTestDevice(AdRequest.TEST_EMULATOR);
AdView adView = new AdView(this, AdSize.BANNER, "a14d9..........");//MY_AD_UNIT_ID
AdRequest adRequest = new AdRequest();
adRequest.setTesting(true); // deprecated
adRequest.addTestDevice(AdRequest.TEST_EMULATOR); // OK
adView.loadAd(adRequest);
public class MyClass extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
String sMyText = "some text";
int nMyInt = 10;
@Override
protected void onSaveInstanceState(Bundle outState) {
// Save away the original text, so we still have it if the activity
// needs to be killed while paused.
outState.putString("my_text", sMyText);
outState.putInt("my_int", nMyInt);
Toast.makeText(this, "onSaveInstanceState()", Toast.LENGTH_LONG).show();
Log.i("onSaveInstanceState", "onSaveInstanceState()");
}
String sNewMyText = "";
int nNewMyInt = 0;
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
// restore saved values
sNewMyText = savedInstanceState.getString("my_text");
nNewMyInt = savedInstanceState.getInt("my_int");
Toast.makeText(this, "onRestoreInstanceState()", Toast.LENGTH_LONG).show();
Log.i("onRestoreInstanceState", "onRestoreInstanceState()");
}
}
GregorianCalendar cal = new GregorianCalendar(); Boolean b = cal.isLeapYear(2012); // true, Android example.
public class MainActivity extends Activity {
TextView txtV;
Context cntx;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
txtV = (TextView)findViewById(R.id.idLabel);
cntx = this;
StringBuilder strBuild = new StringBuilder();
GregorianCalendar cal = new GregorianCalendar();
Boolean b = cal.isLeapYear(2012); // true
strBuild.append("Is leap year 2012? " + b + "
");
b = cal.isLeapYear(2014); // false
strBuild.append("Is leap year 2014? " + b + "
");
txtV.setText(strBuild);
}
}
Why the app selects data from basic layout folder if smallest width is higher then the number in folder name?
Example 1
layout-sw600dp values-sw600dp (smallest width sw for data usage from this folder is 600dp density independent pixel!!!!!)
Device screen resolution is 1200 x 900 px (pixel) Wow, app to be select data from sw600dp folder! Realy?
DPI of device screen - dot per inch (pixel per inch) is 480 pixel it is wery important number!
In our case smallest dimension of screen must be at least 1800 real - physical pixels (1800 px / 3 ratio(dpi/160) = 600 dp (dip density independend pixels) to be used data from folders values-sw600dp and layout-sw600dp.
Example 2 see Example 1 abouve
Device: Nexus 7 (2012) selected from Android Studio tool layout editor
Resolution: 800x1280 px
DPI: tvdpi (approximately 213dpi)
Ratio: 1.33 (213 / 160)
Smallest width in px: 800
Convert px to dp: 601.5 (800 / 1.33)
Result:Smallest width is 601.5dp The App to be used data from folders values-sw600dp and layout-sw600dp.
Example 1
layout-sw600dp values-sw600dp (smallest width sw for data usage from this folder is 600dp density independent pixel!!!!!)
Device screen resolution is 1200 x 900 px (pixel) Wow, app to be select data from sw600dp folder! Realy?
DPI of device screen - dot per inch (pixel per inch) is 480 pixel it is wery important number!
- App selects smallest dimension of screen. In our case 900 px
Medium screen have 160 dpi (The density-independent pixel is equivalent to one physical pixel on a 160 dpi screen, which is the baseline density assumed by the system for a "medium" density screen.). - App calculate ratio 480 / 160 = 3 (The conversion of dp units to screen pixels: px = dp * (dpi / 160))
- App calculate smallest dimesnion of screen in dp 900 / 3 = 300 dip or dp (density independed pixel).
- App selects data from basic values and layout folder because sw600dp is greater than 300dp.
In our case smallest dimension of screen must be at least 1800 real - physical pixels (1800 px / 3 ratio(dpi/160) = 600 dp (dip density independend pixels) to be used data from folders values-sw600dp and layout-sw600dp.
Example 2 see Example 1 abouve
Device: Nexus 7 (2012) selected from Android Studio tool layout editor
Resolution: 800x1280 px
DPI: tvdpi (approximately 213dpi)
Ratio: 1.33 (213 / 160)
Smallest width in px: 800
Convert px to dp: 601.5 (800 / 1.33)
Result:Smallest width is 601.5dp The App to be used data from folders values-sw600dp and layout-sw600dp.
Editace: 2011-10-03 12:34:27
Počet článků v kategorii: 396
Url:file-open-read-to-stringbuilder-close-java-example