Android Studio gradle file comment same as java comment
// single line
/*
multi line
*/
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Old code with HashMap
Lint warning:
Use new SparseArray(...) instead for better performance
Issue: Looks for opportunities to replace HashMaps with the more efficient SparseArray
Id: UseSparseArrays
New code with SparseArray
SparseArray methods:
//developer.android.com/reference/android/util/SparseArray.html
Map<Integer, Bitmap> _bitmapCache = new HashMap<Integer, Bitmap>();
private void fillBitmapCache() {
_bitmapCache.put(R.drawable.icon, BitmapFactory.decodeResource(getResources(), R.drawable.icon));
_bitmapCache.put(R.drawable.abstrakt, BitmapFactory.decodeResource(getResources(), R.drawable.abstrakt));
_bitmapCache.put(R.drawable.wallpaper, BitmapFactory.decodeResource(getResources(), R.drawable.wallpaper));
_bitmapCache.put(R.drawable.scissors, BitmapFactory.decodeResource(getResources(),
}
Bitmap bm = _bitmapCache.get(R.drawable.icon);
Lint warning:
Use new SparseArray
Issue: Looks for opportunities to replace HashMaps with the more efficient SparseArray
Id: UseSparseArrays
New code with SparseArray
SparseArray<Bitmap> _bitmapCache = new SparseArray<Bitmap>();
private void fillBitmapCache() {
_bitmapCache.put(R.drawable.icon, BitmapFactory.decodeResource(getResources(), R.drawable.icon));
_bitmapCache.put(R.drawable.abstrakt, BitmapFactory.decodeResource(getResources(), R.drawable.abstrakt));
_bitmapCache.put(R.drawable.wallpaper, BitmapFactory.decodeResource(getResources(), R.drawable.wallpaper));
_bitmapCache.put(R.drawable.scissors, BitmapFactory.decodeResource(getResources(),
}
Bitmap bm = _bitmapCache.get(R.drawable.icon);
SparseArray methods:
//developer.android.com/reference/android/util/SparseArray.html
How add item to ArrayList, sort ArrayList, search find index of item in ArrayList, min(), max() Java basic example.
import java.util.ArrayList;
import java.util.Collections;
public class MainClass {
public static void main(String[] arg) {
String[] arrayOfString = {"nothing", "Hello", "people"
, "bye-bye", "hello", "world!", "End" };
ArrayList<String> arrayList = new ArrayList<String>();
for(String s: arrayOfString)
arrayList.add(s);
Collections.sort(arrayList);
// foreach
for (String str: arrayList)
System.out.println(str);
Object objMin = Collections.min(arrayList);
System.out.println("Min is: " + objMin);
Object objMax = Collections.max(arrayList);
System.out.println("Max is: " + objMax);
int index = Collections.binarySearch(arrayList, "people");
System.out.println("Index of people is: " + index);
}
}
/*
End
Hello
bye-bye
hello
nothing
people
world!
Min is: End
Max is: world!
Index of people is: 5
*/
Integer, Float, String, List passed as reference in JAVA example source code:
// List passed as reference JAVA
List<Integer>list = new ArrayList<Integer>();
public void fc (List<Integer>listRef){
listRef.add(7);
listRef.add(5);
}
fc(list); // 7, 5
// String passed as reference JAVA
public void mutate(AtomicReference<Object> ref) { ref.set("Goodbye"); }
AtomicReference<Object> ref = new AtomicReference<Object>("Hello");
mutate(ref);
System.out.println(ref.get()); //Goodbye!
String s = (String) ref.get();
// Integer passed as reference JAVA
private static void mutate(AtomicReference<Object> ref) { ref.set(7); }
//public static void main(String[] arg) {
AtomicReference<Object> ref = new AtomicReference<Object>(5);
mutate(ref);
System.out.println(ref.get()); // 7
int n = (Integer) ref.get();
// Float passed as reference JAVA
private static void mutate(AtomicReference<Object> ref) { ref.set(14.8f); }
//public static void main(String[] arg) {
AtomicReference<Object> ref = new AtomicReference<Object>(12.1f);
mutate(ref);
float f = (Float) ref.get();
System.out.println(f); //14.8
How setup color coloring highlight highlighting syntax font size and family in Eclipse Java and XML editor Android example
Java editor
xml editor
xml editor double click in Preferences dialog on xml -> Editor -> Syntax coloring
[caption id="attachment_627" align="alignleft" width="297" caption="Eclipse editor syntax color settings"][/caption]
Java editor
- Go to Eclipse menu Window -> Preferences
- Doubleclick on Java
- Double click on Editor
- Select Java, Javadocs or Comments and setup color and font
- Font size and family change from Window->Preferences-> General->Appearance->Colors and Fonts
- Press OK for saving changes
xml editor
xml editor double click in Preferences dialog on xml -> Editor -> Syntax coloring
[caption id="attachment_627" align="alignleft" width="297" caption="Eclipse editor syntax color settings"][/caption]
Get key by value from Map Java Android example
MainClass.java
MainClass.java
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
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", "two sets of;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);
}
}
if (map.containsValue("zwei")) {
Set<String> references = getKeysByValue(map, "zwei");
Iterator<String> it = references.iterator();
while (it.hasNext()) {
String key = (String) it.next();
String value = map.get(key);
System.out.println(key + " = " + value);
}
}
}
public static <T, E> Set<T> getKeysByValue(Map<T, E> map, E value) {
Set<T> keys = new HashSet<T>();
for (Entry<T, E> entry : map.entrySet()) {
if (entry.getValue().equals(value)) {
keys.add(entry.getKey());
}
}
return keys;
}
}
/*
two = zwei
two sets of = zwei
*/
Editace: 2016-03-12 19:38:38
Počet článků v kategorii: 396
Url:android-studio-gradle-file-comment-same-as-java-comment