Guava: GOOGLE CORE LIBRARIES for Java Tutorial and Example
Title: Guava: Google Core Libraries for Java Tutorial and Example
Introduction:
Guava (Google Core Library) is a powerful tool -class library provided by Google for Java developers.It contains many practical functions and tools, making Java development more convenient and efficient.In this tutorial, we will introduce how to use the Guava library and provide some Java code examples to help you better understand and apply various functions of Guava.
Table of contents:
1. Introduction to Guava
2. The installation and configuration of Guava
3. Common Guava function introduction
3.1 Early Tool Class
3.2 String Tool Class
3.3 functional programming
3.4 cache tool class
4. Guava sample code
4.1 Early Tool Class Example
4.2 Spectering Tool Class Example
4.3 Functional Programming Example
4.4 Example of cache tool
5. Summary
1. Guava Introduction:
Guava is an open source Java class library that developed and maintained by the Google team.It provides a lot of practical tools to help Java developers handle common programming tasks more efficiently.This includes tools for processing sets, string, functional programming, cache and other aspects.
2. Installation and configuration of Guava:
In order to use the Guava library, you need to add corresponding dependencies in the project.You can add dependencies through building tools such as Maven or Gradle.Make sure your project configuration is correct, and you can access the GUAVA library required below the Maven central warehouse.
3. Common Guava feature introduction:
3.1 Equity Tools:
Guava provides a series of convenient collection tools, such as Immutable collection, Multiset, Multimap, etc.These tools greatly simplify the complexity of the collection operation and provide more efficient collection processing methods.
3.2 String tools:
The Guava string tool class provides many convenient methods for string processing, such as splitting, connecting, filling, interception, etc.They are all threads and high efficiency.
3.3 Functional programming:
GUAVA provides powerful functional programming support, such as functional interfaces, optional value, predefined functions, etc.These functions make us more elegant functional programming, simplify code, and improve readability.
3.4 cache tools:
The GUAVA cache tools allow us to easily create and manage cache, and improve the performance and response speed of the program.It supports a variety of cache strategies based on size, time, and reference, which is very suitable for use when it needs to process frequent access.
4. Guava example code:
Next, we will provide some Guava example code to help you better understand and apply these functions.
4.1 Early Tool Class Example:
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import java.util.List;
import java.util.Map;
public class GuavaCollectionsExample {
public static void main(String[] args) {
List<String> list = Lists.newArrayList("apple", "banana", "orange");
Map<String, Integer> map = Maps.newHashMap();
map.put("apple", 1);
map.put("banana", 2);
map.put("orange", 3);
System.out.println(list);
System.out.println(map);
}
}
4.2 Spectering Tool Class:
import com.google.common.base.Joiner;
import com.google.common.base.Splitter;
public class GuavaStringsExample {
public static void main(String[] args) {
String joinedString = Joiner.on(",").join("apple", "banana", "orange");
System.out.println(joinedString);
Iterable<String> splitStrings = Splitter.on(",").split(joinedString);
for (String splitString : splitStrings) {
System.out.println(splitString);
}
}
}
4.3 Functional programming example:
import com.google.common.base.Function;
import com.google.common.collect.Lists;
import java.util.List;
public class GuavaFunctionalExample {
public static void main(String[] args) {
List<Integer> numbers = Lists.newArrayList(1, 2, 3, 4, 5);
List<Integer> squaredNumbers = Lists.transform(numbers, new Function<Integer, Integer>() {
@Override
public Integer apply(Integer number) {
return number * number;
}
});
System.out.println(squaredNumbers);
}
}
4.4 Example of cache tool class:
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import java.util.concurrent.TimeUnit;
public class GuavaCacheExample {
public static void main(String[] args) {
Cache<String, String> cache = CacheBuilder.newBuilder()
.maximumSize(100)
.expireAfterWrite(10, TimeUnit.MINUTES)
.build();
cache.put("key1", "value1");
cache.put("key2", "value2");
String value1 = cache.getIfPresent("key1");
System.out.println(value1);
}
}
5. Summary:
This tutorial introduces the use and common functions of the Guava library, and provides some Java code examples.Through learning and practicing these examples, you will better understand and master the Guava library, thereby improving the efficiency and quality of Java development.I hope this tutorial will help you!
