SyntaxHighlighter

Tuesday, July 9, 2013

Loading Multiple Spring Application Contexts with their own ClassLoader

Loading Multiple Spring Application Contexts with their own ClassLoader


here's a quick snippet to support creating an application context with it's own classloader.

package de.incompleteco.spring.context;

import java.io.File;
import java.net.URL;
import java.net.URLClassLoader;

import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.GenericApplicationContext;
import org.springframework.core.io.DefaultResourceLoader;

public class ApplicationContextClassLoader {

 public ClassLoader getClassLoader(String location) throws Exception {
  File f = new File(location);
  return new URLClassLoader(new URL[]{f.toURI().toURL()});
 }

 public ApplicationContext getContext(String location,String... contextPaths) throws Exception {
  return getContext(null,location,contextPaths);
 } 
 
 public ApplicationContext getContext(ApplicationContext parentContext,String location,String... contextPaths) throws Exception {
  //init
  GenericApplicationContext context = new GenericApplicationContext(); 
  //build the app context
  if (parentContext != null) {
   context = new GenericApplicationContext(parentContext);
  }//end if
  XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(context);
  //get the classloader
  ClassLoader loader = getClassLoader(location);
  //set the loader
  reader.setBeanClassLoader(loader);
  reader.setResourceLoader(new DefaultResourceLoader(loader));
  //get the bean definitions
  reader.loadBeanDefinitions(contextPaths);
  //init
  context.refresh();
  //return
  return context;
 }
 
}


this supports XML configuration but annotation can be swapped in/out as the case may require.  i'm sure there are prettier ways and i'll tighten it up when i get the chance

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