Android Support Library Collection's technical principles in the Java library
Android Support Library Collection's technical principles in the Java library
Summary:
Android Support Library Collections is a set of data structures and algorithms commonly used in Android development.This article will analyze the technical principles of the framework in the Java library and provide practical examples to help developers better apply the Collections framework in the Android project.
introduce:
The Collections framework provides rich data structure and algorithm implementation, so that Android developers can handle various data more conveniently.It is built on the Java collection framework (Java.util package) and optimizes and expands to meet the special needs of Android application development.
The key to using the Collections framework in Java is to introduce related packages and classes.Here are some commonly used classes in the COLLECTIONS framework:
1. ArrayMap: ArrayMap is an efficient key value pair implementation. It uses two parallel array to store keys and values.The use of ArrayMap saves memory space more than HashMap, and it can maintain the order of elements during the duration.
Example code:
ArrayMap<String, Integer> map = new ArrayMap<>();
map.put("apple", 1);
map.put("orange", 2);
map.put("banana", 3);
int value = map.get("apple");
for (int i = 0; i < map.size(); i++) {
String key = map.keyAt(i);
int val = map.valueAt(i);
// Treat the key value pair
}
2. Sparsearray: Sparsearray is a mapping for a large amount of sparse data.It is similar to ArrayMap, but it saves more in the memory occupation, and it is suitable for a small value range with a small value range.
Example code:
SparseArray<String> array = new SparseArray<>();
array.put(10, "apple");
array.put(20, "orange");
array.put(30, "banana");
String value = array.get(10);
for (int i = 0; i < array.size(); i++) {
int key = array.keyAt(i);
String val = array.valueAt(i);
// Treat the key value pair
}
3. LongSparsearray: Similar to Sparsearray, but using the Long type as a key, it is suitable for the large range of the key range.
Example code:
LongSparseArray<String> array = new LongSparseArray<>();
array.put(1000000L, "apple");
array.put(2000000L, "orange");
array.put(3000000L, "banana");
String value = array.get(1000000L);
for (int i = 0; i < array.size(); i++) {
long key = array.keyAt(i);
String val = array.valueAt(i);
// Treat the key value pair
}
in conclusion:
Android Support Library Collection's framework is a very practical tool in the development of Android. It can provide efficient performance and low memory consumption when processing data.Through the analysis and practical examples of this article, developers can more deeply understand the technical principles of the Collections framework and are flexibly applied in the Android project.In actual projects, you can choose the appropriate data structure and algorithm to improve the performance and user experience according to the needs of the scene.
