Introducing Spring Framework

Chapter 4 ■ Using Beans Scopes
public ServiceSearchEngine(){
if(log.isDebugEnabled())
log.debug("ServiceSearchEngine created: " + this);
}
public DocumentDAO getDocumentDAO() {
return documentDAO;
}
public void setDocumentDAO(DocumentDAO documentDAO) {
if(log.isDebugEnabled())
log.debug("Document DAO set: " + documentDAO);
}
this.documentDAO = documentDAO;
public List findByType(Type documentType) {
List result = new ArrayList();
for(Document doc : listAll()){
if(doc.getType().getName().equals(documentType.getName()))
result.add(doc);
}
return result;
}
public List listAll() {
return Arrays.asList(documentDAO.getAll());
}
}
In Listing 4-1 you have just added a Logger into your ServiceSearchEngine class using the SLF4J library.
Also, you added a constructor for this class, and you have set the level of debug in the same constructor and in the
setter method for your DocumentDAO implementation. With this, every time the container creates an instance, you
should see ServiceSearchEngine create: with some object ID. When the container sets your DocumentDAO
implementation, you should see the output Document DAO set: with some Object ID. For now you haven’t
changed anything in the code; you only added the Logger just to illustrate what the Spring container is doing when it
creates your beans.
Now let’s see Listing 4-2, the class MyDocumentTest, because you need to modify it in order to see some of these
bean scopes.
Listing 4-2. MyDocumentTest.java
package com.apress.isf.spring.test;
import static org.junit.Assert.*;
import java.util.List;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;
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