Detailed documentation and instructions for the Android Support Library Core Utilities framework

Detailed documentation and examples of the Android Support Library Core Utilities framework Overview: Android Support Library Core Utilities is a powerful framework designed to provide various core functionalities and tool classes to help developers simplify the development process of Android applications. This article will introduce the detailed documentation of the framework and provide some sample code to demonstrate its usage. Document: 1. CollectionUtils: CollectionUtils provides many practical methods for manipulating and processing collections. Here are some examples of commonly used methods: List<String> myList = new ArrayList<>(); myList.add("Apple"); myList.add("Orange"); myList.add("Banana"); Boolean containsApple=CollectionUtils. contains (myList, "Apple")// Check if the list contains' Apple ' Int count=CollectionUtils. countMatches (myList, "Apple")// Calculate the number of occurrences of 'Apple' in the list CollectionUtils.filter(myList, new Predicate<String>() { @Override public boolean evaluate(String item) { Return item. startsWith ("A")// Filter out elements starting with 'A' } }); 2. Data Structure Tool Class (DataUtil): DataUtil provides some commonly used data structures and tool methods. Here are some examples: SparseArray<String> sparseArray = new SparseArray<>(); sparseArray.put(0, "Zero"); sparseArray.put(1, "One"); sparseArray.put(2, "Two"); Int size=DataUtil. size (sparseArray)// Obtain the size of SparseArray Boolean isEmpty=DataUtil. isEmpty (sparseArray)// Check if SparseArray is empty DataUtil. repainAll (sparseArray, Arrays. asList (1, 2))// Preserve the keys specified in SparseArray 3. FileUtils: FileUtils provides a set of practical methods for handling files and directories. Here are some examples: File file = new File("/path/to/file.txt"); Boolean isFileExists=FileUtils. isFileExists (file)// Check if the file exists Long fileSize=FileUtils. sizeOf (file)// Obtain the size of the file String fileExtension=FileUtils. getFileExtension (file)// Obtain the extension of the file Example code: 1. Use CollectionUtils to filter out elements starting with 'A': List<String> myList = new ArrayList<>(); myList.add("Apple"); myList.add("Orange"); myList.add("Banana"); Log.d("Filtered List", CollectionUtils.filter(myList, new Predicate<String>() { @Override public boolean evaluate(String item) { return item.startsWith("A"); } }).toString()); //The output result is: [Apple] 2. Use SparseArray to obtain the number of keys: SparseArray<String> sparseArray = new SparseArray<>(); sparseArray.put(0, "Zero"); sparseArray.put(1, "One"); sparseArray.put(2, "Two"); Log.d("SparseArray Size", String.valueOf(DataUtil.size(sparseArray))); //The output result is: 3 3. Use FileUtils to obtain the file size and extension: File file = new File("/path/to/file.txt"); Log.d("File Size", String.valueOf(FileUtils.sizeOf(file))); //The output result is: file size (in bytes) Log.d("File Extension", FileUtils.getFileExtension(file)); //The output result is: txt Conclusion: Android Support Library Core Utilities provides a powerful set of tool classes and methods to help developers more easily handle collections, data structures, and files. Through detailed documentation and sample code, developers can better understand and use the framework, thereby improving the development efficiency of Android applications.