Apache Groovy's common questions in the development of Java libraries
Apache Groovy's common questions in the development of Java libraries
Apache Groovy is a dynamic script language based on the Java platform, which can be seamlessly integrated with Java.In the development of the Java library, using Groovy can write code more concise and flexibly.This article will answer Apache Groovy's common problems in the development of Java libraries and provide the corresponding Java code examples to help understand.
1. How to use the Java library in Groovy?
In Groovy, you can directly import and use the Java class library, which is no different from Java code.For example, after importing the Java library, you can directly call the methods and fields.
groovy
import java.util.ArrayList
def list = new ArrayList()
list.add("Groovy")
list.add("Java")
println(list)
2. How to use the Getter and Setter of the Java class in Groovy?
In Groovy, you can directly access the fields of the Java class, and automatically call the corresponding Getter and Setter method.No need to write the getter and setter method manually.
groovy
class Person {
String name
}
def person = new Person()
Person.name = "John" // Corresponding to the setter method
Println (Person.Name) // Corresponding to the getter method
3. How to call the static method of the Java library in Groovy?
You can use Java's class name to directly call the static method.If the static method has parameters, the parameters can be passed in a way of naming parameters.
groovy
import java.lang.Math
def squareRoot = Math.sqrt(16)
println(squareRoot)
4. How to deal with Java abnormalities in Groovy?
In Groovy, the Try-Catch statement can be used to deal with Java abnormalities, including capturing the abnormalities of specific types and multiple abnormal capture.
groovy
try {
// Purchase here that may be thrown out of an abnormality.
} catch (IOException e) {
Println ("IO abnormal:" + e.getMessage ())
} catch (Exception e) {
Println ("Other abnormalities:" + E.Getmessage ())
}
5. How to use Java generics in Groovy?
In Groovy, you can use Java generics directly, and use generic classes like ordinary classes.
groovy
import java.util.ArrayList
def list = new ArrayList<String>()
list.add("Java")
list.add("Groovy")
println(list)
6. How to use Java annotations in Groovy?
In Groovy, you can use Java annotations and use it directly through@symbols.Groovy also supports custom annotations.
groovy
import java.lang.Override
class Person {
@Override
String toString() {
return "Person"
}
}
def person = new Person()
println(person)
Summarize:
This article answers some of the common problems in the development of Apache Groovy in the development of Java libraries, and provides the corresponding Java code example.It is hoped that this article can help readers better understand and apply Apache Groovy's knowledge in the development of Java libraries.
