Guava: GOOGLE CORE LIBRARIES for Java framework
Guava: GOOGLE CORE LIBRARIES for Java framework
Guava is a powerful Java core library developed by Google, which aims to provide high -efficiency and easy -to -use tools and utility to enhance the work efficiency of Java developers.This article will discuss some of the main characteristics of the Guava library and provide some Java code examples to demonstrate their usage.
1. Collections:
The GUAVA collection tool class provides many useful expansion functions for the Java collection framework.The following are sample code for some collection tools:
import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
public class CollectionsExample {
public static void main(String[] args) {
// Create a new list with Lists tool
List<String> names = Lists.newArrayList("Alice", "Bob", "Charlie");
// Use the SETS tool to create a new collection
Set<Integer> numbers = Sets.newHashSet(1, 2, 3, 4, 5);
// Use a collection tool class for filtering and conversion operation
List<String> filteredNames = Lists.newArrayList(Collections2.filter(names, name -> name.startsWith("A")));
Set<String> transformedNames = Sets.newHashSet(Collections2.transform(names, String::toUpperCase));
}
}
2. String operation (String Utilities):
GUAVA provides many practical string operation methods to make the processing string more convenient.Here are some commonly used string operation example code:
import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
import com.google.common.base.Strings;
public class StringsExample {
public static void main(String[] args) {
// Use the Joiner tool class to connect the string list into a single string
List<String> names = Arrays.asList("Alice", "Bob", "Charlie");
String concatenatedNames = Joiner.on(", ").join(names);
// Use the Splitter tool class to split the string into a list
String sentence = "Hello, world! This is Guava library.";
List<String> words = Lists.newArrayList(Splitter.on(" ").split(sentence));
// Use the Strings Tool Class to check whether the strings are empty or blank
String text = "Guava";
boolean isNullOrEmpty = Strings.isNullOrEmpty(text);
boolean isNullOrWhitespace = Strings.isNullOrEmpty(text);
}
}
3. Caching:
The GUAVA cache tools make it easier to achieve cache in the application.The following is a simple cache sample code:
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
public class CacheExample {
public static void main(String[] args) {
// Create a cache instance
Cache<Integer, String> myCache = CacheBuilder.newBuilder().maximumSize(100).build();
// Put the key value pair to the cache
myCache.put(1, "Alice");
myCache.put(2, "Bob");
myCache.put(3, "Charlie");
// Get the value from the cache
String name = myCache.getIfPresent(1);
}
}
The above are just some functions and usage examples of the Guava library, and there are many other practical tools and classes available for developers.Whether it is processing collection, string, or cache function, Guava can bring convenience and efficiency to Java developers.
