How to get osgi configuration values to a servlet - ajax

Question

This is my OSGI configuration file which is having three names. I want to read these values in a servlet and sort them Alphabetically and send that response to a ajax to display in a custom component AEM.
package com.demo.training.core.services.impl;
import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.metatype.annotations.AttributeDefinition;
import org.osgi.service.metatype.annotations.AttributeType;
import org.osgi.service.metatype.annotations.Designate;
import org.osgi.service.metatype.annotations.ObjectClassDefinition;
import com.demo.training.core.services.MyProjectServ;
#Component(service=MyProjectServ.class,immediate = true)
#Designate(ocd= MyProject.ServiceConfig.class)
public class MyProject implements MyProjectServ {
#ObjectClassDefinition(name="My-Project OSGI",
description="Demo OSGI configuration")
public #interface ServiceConfig {
#AttributeDefinition(
name="Name1",
description="Add First name",
type = AttributeType.STRING
)
public String Name1() default "Abhinay";
#AttributeDefinition(
name="Name2",
description="Add second name ",
type = AttributeType.STRING
)
public String Name2() default "Pavan";
#AttributeDefinition(
name="Name3",
description="Add third name ",
type = AttributeType.STRING )
public String Name3() default "Ram";
}
private String Name1;
private String Name2;
private String Name3;
#Activate
protected void activate(ServiceConfig myconfig) {
Name1=myconfig.Name1();
Name2=myconfig.Name2();
Name3=myconfig.Name3();
}
#Override
public String getNAME1() {
return Name1; }
#Override
public String getNAME2() {
return Name2; }
#Override
public String getNAME3() {
return Name3;
} }
'''This is my Servlet code , I have wrote multiple resp.getwriter() to see upto which line it is working. It is working upto response named a1(i.e below dictionary command). Could anyone please help to get values from osgi configuration to this servlet ?
package com.demo.training.core.servlets;
import java.io.IOException;
import java.util.Arrays;
import java.util.Dictionary;
import javax.servlet.Servlet;
import javax.servlet.ServletException;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.HttpConstants;
import org.apache.sling.api.servlets.SlingAllMethodsServlet;
import org.osgi.framework.Constants;
import org.osgi.service.cm.Configuration;
import org.osgi.service.cm.ConfigurationAdmin;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Reference;
#Component(service=Servlet.class,
property={
Constants.SERVICE_DESCRIPTION + "=Practice Servlet",
"sling.servlet.methods=" + HttpConstants.METHOD_GET,
"sling.servlet.methods=" + HttpConstants.METHOD_POST,
"sling.servlet.paths=/bin/myproject",
"sling.servlet.extensions=" + "txt"
})
public class MyProjectServlet extends SlingAllMethodsServlet {/**
*
*/
private static final long serialVersionUID = 1L;
#Reference
private ConfigurationAdmin MYPROJECT_CONFIG;
private static final String MY_PROJECT="com.demo.training.core.services.impl.MyProject";
#Override
protected void doGet(final SlingHttpServletRequest req,
final SlingHttpServletResponse resp) throws ServletException, IOException {
Configuration My_Servlet=MYPROJECT_CONFIG.getConfiguration(MY_PROJECT);
Dictionary<String,Object> property =My_Servlet.getProperties();
resp.getWriter().write("a1");
String first=property.get("Name1").toString();
String second=property.get("Name2").toString();
String third=property.get("Name3").toString();
resp.getWriter().write("a2");
resp.getWriter().write(first);
resp.getWriter().write("a3");
String[] myArray = new String[]{first,second,third};
Arrays.sort(myArray);
String js=myArray.toString();
resp.getWriter().write(js);
}
}

Answer 1

You try to use the #reference annotation for your service. If this object null you can use the ResourceResolverFactoy. This object does always exists, else you have your instance has a serious problem:
Map<String, Object> serviceParameter = new HashMap<>();
serviceParameter.put(ResourceResolverFactory.SUBSERVICE, Put the name name of your service here);
return resolverFactory.getServiceResourceResolver(serviceParameter);
In Servlet use annotation #reference to inject the ResourceResolverFactoy:
#Reference
private ResourceResolverFactory ...;
By the way, have an eye to java code convetions. Method names starts always with smal letters even in service configs.