[Java Spring] Spring Annotation Configuration Using XML

Add context to our application.

main/resources/applicationContext.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd">

    <context:annotation-config />

    <context:component-scan base-package="com.pluralsight" />
</beans>

Using annotation for @Service @Repository @Controller:

/repository/HibernateCustomerRepositoryImpl.java:

package com.pluralsight.repository;

import com.pluralsight.model.Customer;

import org.springframework.stereotype.Repository;

import java.util.ArrayList;
import java.util.List;

@Repository("customerRepository")
public class HibernateCustomerRepositoryImpl implements CustomerRepository {

    @Override
    public List<Customer> findAll() {
        List<Customer> customers = new ArrayList<>();
        Customer customer = new Customer();

        customer.setFirstname("Byran");
        customer.setLastname("John");

        customers.add(customer);

        return customers;
    }
}

/service/CustomerServiceImpl.java:

We use @Autowrie for the member of Repository.

package com.pluralsight.service;

import com.pluralsight.model.Customer;
import com.pluralsight.repository.CustomerRepository;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service("customerService")
public class CustomerServiceImpl implements CustomerService {

    @Autowired
    private CustomerRepository customerRepository;

    @Override
    public List<Customer> findAll() {
        return customerRepository.findAll();
    }

}

We can also use Setter Injection:

    private CustomerRepository customerRepository;

    @Autowired
    public CustomerServiceImpl (CustomerRepository customerRepository) {
        this.customerRepository = customerRepository;
    }

We can also use Constructor Injection:

    private CustomerRepository customerRepository;

    @Autowired
    public CustomerServiceImpl (CustomerRepository customerRepository) {
        this.customerRepository = customerRepository;
    }

After using Annotations & Autowired, we code looks simple and decoupled

原文地址:https://www.cnblogs.com/Answer1215/p/9515394.html