Android Support Library Collection's skills and precautions for usage

Android Support Library Collection Skills and Precautions Android Support Library Collections (Android support library collection) framework is a powerful tool provided by the Android platform to simplify the task of developers when processing the collection data.It provides a series of practical categories and methods that can help developers operate the collection data more efficiently, while compatible with different versions of Android systems. This article will introduce some techniques and precautions to use the Android Support Library Collections framework, and provide the corresponding Java code example. 1. Import SUPPORT LIBRARY Collections To use Android Support Library Collections framework, you first need to add related dependencies to the project's built.gradle file.Please make sure you have imported the latest version of SUPPORT-COLLECTION: dependencies { implementation 'com.android.support:support-collection:28.0.0' } 2. Use Sparsearray instead of HashMap In Android development, the collection structure of key value pairs often needs to be used.Traditional HashMap has high memory occupation when the amount of data is large.The Sparsearray class provided by Android is a better choice, and its memory optimization effect is better.Use Sparsearray to replace HashMap can significantly reduce memory occupation, especially suitable for storing sparse data. Below is an example using Sparsearray: SparseArray<String> sparseArray = new SparseArray<>(); sparseArray.put(1, "John"); sparseArray.put(2, "Alice"); sparseArray.put(3, "Bob"); String name = sparsearray.get (2); // Get the value of key 2 3. Use ArrayMap instead of hashmap In some cases, the collection of key value pairs is required, but when the amount of data is not large, you can consider using ArrayMap instead of HashMap.ArrayMap is a optimized version of HashMap, which has obvious advantages in memory occupation and performance. The following is an example of using ArrayMap: ArrayMap<String, Integer> arrayMap = new ArrayMap<>(); arrayMap.put("apple", 5); arrayMap.put("banana", 3); arrayMap.put("orange", 8); int count = ArrayMap.get ("banana"); // Get the value of "banana" as "banana" 4. Use SparseBooleanarray instead of BitSet BitSet is a collection class that stores Boolean, but it is high in memory consumption.If you only need to store a small amount of Boolean value, you can consider using the SparseBooleanarray class to replace BitSet, which has a better memory optimization effect. The following is an example of using Sparsebooleanarray: SparseBooleanArray sparseBooleanArray = new SparseBooleanArray(); sparseBooleanArray.put(1, true); sparseBooleanArray.put(2, false); sparseBooleanArray.put(3, true); boolean value = sparsebooleanarray.get (2); // Get the Boolean value of key 2 5. Use LongSparsearray instead of HashMap <Long, T> If you need to store a collection of key -length -key pairs, you can use the LONGSPARSEARRAY class instead of HashMap <Long, T>, which has good advantages in memory occupation and performance. The following is an example of using LongSparsearray: LongSparseArray<String> longSparseArray = new LongSparseArray<>(); longSparseArray.put(1001L, "John"); longSparseArray.put(1002L, "Alice"); longSparseArray.put(1003L, "Bob"); String name = longSparsearray.get (1002L); // Get the value of 1002L 6. Forced use of ITATOR instead of for-Each When using Android support library collections, try to use the Iterator iterator to traverse the collection instead of the for-Each cycle.This is because Iterator traverses the elements in the set while traversing, and the for-Each cycle does not support modification operations. List<String> list = new ArrayList<>(); list.add("apple"); list.add("banana"); list.add("orange"); Iterator<String> iterator = list.iterator(); while (iterator.hasNext()) { String item = iterator.next(); if (item.equals("banana")) { Iterator.remove (); // Delete elements } } 7. Pay attention to thread security When using Android Support Library Collections framework, you need to pay attention to the security of the client.If you read and write the same episode in multiple threads, you need to take corresponding thread synchronization measures, such as using a set of sets of threads or using your lock mechanism to ensure the consistency of the data. Although the Android Support Library Collection frame provides some thread -safe set classes (such as SynchronizedSparsearray and SynchronizedArrayMap), pay special attention to use them correctly in multi -threaded environments to avoid data competition and thread security issues. Summarize: The Android SUPPORT LIBRARY Collections framework provides some practical collection classes that can effectively simplify data processing tasks in Android development.When processing collection data, use Sparsearray, ArrayMap, Sparsebooleanarray and LongSparsearray to bring better memory optimization effects, and using Iterator can support the modification operation of the set.At the same time, we need to pay attention to the safety of the set in a multi -threaded environment. The above is some techniques and precautions for using Android Support Library Collections framework.Hope to help your development!