Mincronaut: read and write a property using BeanWrapper

Using BeanWrapper class, we can set and read the property values of a given class.

 

For example, following snippet set the values to employee instance.

final BeanWrapper<Employee> wrapper = BeanWrapper.getWrapper(new Employee());

wrapper.setProperty("id", 1);
wrapper.setProperty("name", "Krishna");
wrapper.setProperty("age", 34);

 

Below snippet read the values of employee instance.

final int id = wrapper.getRequiredProperty("id", int.class);
final int age = wrapper.getRequiredProperty("age", int.class);
final String name = wrapper.getRequiredProperty("name", String.class);

Find the below working application.

 

Step 1: Create new maven project ‘micronaut-bean-wrapper-demo’.

 

Step 2: Update pom.xml with maven dependencies.

 

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.sample.app</groupId>
	<artifactId>micronaut-bean-wrapper-demo</artifactId>
	<version>1</version>

	<properties>
		<maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
		<micronaut.version>3.7.2</micronaut.version>
		<slf4j.version>2.0.3</slf4j.version>

		<maven.compiler.target>15</maven.compiler.target>
		<maven.compiler.source>15</maven.compiler.source>
	</properties>

	<dependencies>

		<dependency>
			<groupId>io.micronaut</groupId>
			<artifactId>micronaut-inject-java</artifactId>
			<version>${micronaut.version}</version>
		</dependency>
		<dependency>
			<groupId>io.micronaut</groupId>
			<artifactId>micronaut-runtime</artifactId>
			<version>${micronaut.version}</version>
		</dependency>


		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-api</artifactId>
			<version>${slf4j.version}</version>
		</dependency>
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-simple</artifactId>
			<version>${slf4j.version}</version>
		</dependency>
	</dependencies>

	<build>
		<plugins>

			<plugin>
				<artifactId>maven-assembly-plugin</artifactId>
				<configuration>
					<archive>
						<manifest>
							<mainClass>com.sample.app.App</mainClass>
						</manifest>
					</archive>
					<descriptorRefs>
						<descriptorRef>jar-with-dependencies</descriptorRef>
					</descriptorRefs>
				</configuration>

				<executions>
					<execution>
						<id>make-assembly</id>
						<phase>package</phase>
						<goals>
							<goal>single</goal>
						</goals>
					</execution>
				</executions>
			</plugin>

		</plugins>
	</build>
</project>

Step 3: Define Employee class.

 

Employee.java

package com.sample.app.model;

import io.micronaut.core.annotation.Introspected;

@Introspected
public class Employee {

	private int id;
	private String name;
	private int age;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	@Override
	public String toString() {
		return "Employee [id=" + id + ", name=" + name + ", age=" + age + "]";
	}

	
}

Step 4: Define main application class.

 

App.java

package com.sample.app;

import com.sample.app.model.Employee;

import io.micronaut.context.ApplicationContext;
import io.micronaut.core.beans.BeanWrapper;

public class App {

	public static void main(String[] args) {
		try (ApplicationContext applicationContext = ApplicationContext.run()) {

			final BeanWrapper<Employee> wrapper = BeanWrapper.getWrapper(new Employee());

			System.out.println("Setting employee instance properties");
			wrapper.setProperty("id", 1);
			wrapper.setProperty("name", "Krishna");
			wrapper.setProperty("age", 34);
			System.out.println(wrapper.getBean());

			System.out.println("\nReading employee instance properties");
			final int id = wrapper.getRequiredProperty("id", int.class);
			final int age = wrapper.getRequiredProperty("age", int.class);
			final String name = wrapper.getRequiredProperty("name", String.class);

			System.out.println("id : " + id);
			System.out.println("age : " + age);
			System.out.println("name : " + name);

		}

	}
}

Total project structure looks like below.

Build the project using mvn package command.

Navigate to the folder where pom.xml is located and execute the command ‘mvn package’.

Upon command successful execution, you can see the jar file ‘micronaut-bean-wrapper-demo-1-jar-with-dependencies.jar’ in project target folder.

$ls ./target/
archive-tmp
classes
generated-sources
maven-archiver
maven-status
micronaut-bean-wrapper-demo-1-jar-with-dependencies.jar
micronaut-bean-wrapper-demo-1.jar
test-classes

Execute below command to run the application.

java -jar ./target/micronaut-bean-wrapper-demo-1-jar-with-dependencies.jar

$java -jar ./target/micronaut-bean-wrapper-demo-1-jar-with-dependencies.jar
Setting employee instance properties
Employee [id=1, name=Krishna, age=34]

Reading employee instance properties
id : 1
age : 34
name : Krishna

You can download this application from this link.

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