iamitshri

@Component
@Data
@ConfigurationProperties(prefix = "config.demo")
@Validated
public class ConfigPropertiesDemo {
    int numTests;
    @Size(min=3)
    String name;
    float expense;
    boolean booleanYes;

iamitshri

Efficient JPA Querying

• Use join fetch
• Named Entity Graphs https://blog.ippon.tech/boost-the-performance-of-your-spring-data-jpa-application/
  • graph definition can be on the query
  • graph definition can be on the entity so that other methods can re use it.
  • Annotation Named Entity : Used to specify the path and boundaries for a find operation or query.
• Use appropriate fetch types (lazy or eager)

MultipleBagFetchException

• Caused by: org.hibernate.loader.MultipleBagFetchException: cannot simultaneously fetch multiple bags: [com.jpa.experiments.entity.TaskEntity.aspects, com.jpa.experiments.entity.AspectEntity.anchors]

iamitshri

 
spring.datasource.url=jdbc:mysql://host:3306/dbname?autoReconnect=true&useSSL=false&zeroDateTimeBehavior=convertToNull&useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC
spring.datasource.username=username
spring.datasource.password=password

spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true

spring.jpa.generate-ddl=true
spring.jpa.hibernate.ddl-auto=none

iamitshri

package edu.wgu.dm.datagenerator;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Future;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;

iamitshri

package edu.wgu.dm.config;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import javax.servlet.http.HttpServletResponse;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.ResponseStatus;

iamitshri

// Get annotations on the class object
Annotation[] annotations = classobject.getClass()
                                     .getAnnotations();
for (Annotation annotation : annotations) {
            log.debug("annotation type: {}", annotation.annotationType());
            Class<? extends Annotation> type = annotation.annotationType();
            for (Method method : type.getDeclaredMethods()) {
                Object val = method.invoke(annotation, (Object[]) null);
                log.debug("method name: {}, return value:{} return type:{}", method.getName(), val, val.getClass()
                                                                                                       .getName());

iamitshri

static code analysis tools

Unnecessary Code Detector
https://marketplace.eclipse.org/category/free-tagging/find-unused-code

Findbugs
https://marketplace.eclipse.org/content/findbugs-eclipse-plugin

spotbugs

iamitshri

What do these option means?
-B -f pom.xml -X clean install 

iamitshri

As of Spring Framework 4.3, an @Autowired annotation on such a constructor is no longer necessary if the target bean only defines one constructor to begin with. However, if several constructors are available, at least one must be annotated to teach the container which one to use.

Lombok can create a constructor with required arguments. Required arguments are final fields and fields with constraints such as @NonNull.

I have read at few places where it suggest not to use @Autowired on fields. Instead constructor injection is preferred

• https://spring.io/blog/2015/11/29/how-not-to-hate-spring-in-2016#injection
• https://www.vojtechruzicka.com/field-dependency-injection-considered-harmful/

iamitshri

    @PostConstruct
     void started() {
       TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
    }