Ndtyjky

This is my first experience using Spring MVC with REST API for having an angular front end. I created 3 configuration files:

Here is my ApplicationConfig

package com.app.config;



import javax.persistence.EntityManagerFactory;

import javax.sql.DataSource;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.ComponentScan;

import org.springframework.context.annotation.Configuration;

import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

import org.springframework.jdbc.datasource.DriverManagerDataSource;

import org.springframework.orm.jpa.JpaTransactionManager;

import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;

import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;

import org.springframework.transaction.PlatformTransactionManager;

import org.springframework.web.servlet.config.annotation.EnableWebMvc;

import org.springframework.web.servlet.view.InternalResourceViewResolver;

import javax.persistence.EntityManagerFactory;



@SuppressWarnings("unused")

@EnableWebMvc

@Configuration

@ComponentScan("com.app.controller")

@EnableJpaRepositories("com.app.dao")

public class ApplicationConfig {

    @Bean

    public InternalResourceViewResolver setup() {

        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();

        viewResolver.setPrefix("/WEB-INF/views/");

        viewResolver.setSuffix(".jsp");

        return viewResolver;

    }



    @Bean

    public DataSource dataSource() {

        System.out.println("in datasoure");

        DriverManagerDataSource dataSource = new DriverManagerDataSource();

        dataSource.setDriverClassName("com.mysql.jdbc.Driver");

        dataSource.setUrl("jdbc:mysql://localhost:3306/db");

        dataSource.setUsername("root");

        dataSource.setPassword("");

        return dataSource;

    }



    @Bean

    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {

        HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();

        vendorAdapter.setGenerateDdl(true);

        LocalContainerEntityManagerFactoryBean factory = new LocalContainerEntityManagerFactoryBean();

        factory.setJpaVendorAdapter(vendorAdapter);

        factory.setPackagesToScan("com.app.model");

        factory.setDataSource(dataSource());

        return factory;

    }



    @Bean

    public PlatformTransactionManager transactionManager(EntityManagerFactory emf) {

        JpaTransactionManager transactionManager = new JpaTransactionManager();

        transactionManager.setEntityManagerFactory(emf);

        return transactionManager;

    }

}

MVC Config

package com.app.config;



import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.web.servlet.config.annotation.EnableWebMvc;

import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;

import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

import org.springframework.web.servlet.view.InternalResourceViewResolver;



@EnableWebMvc

@Configuration

public class MvcConfig implements WebMvcConfigurer {

    public void configureViewResolvers(ViewResolverRegistry registry) {

        registry.jsp("/WEB-INF/views/", ".jsp");

    }



    @Bean

    public InternalResourceViewResolver setup() {

        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();

        viewResolver.setPrefix("/WEB-INF/views/");

        viewResolver.setSuffix(".jsp");

        return viewResolver;

    }

}

WebInitializer

package com.app.config;



import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;



public class WebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {



    @Override

    protected Class<?> getRootConfigClasses() {

        return null;

    }

    @Override

    protected Class<?> getServletConfigClasses() {

        return new Class { ApplicationConfig.class, MvcConfig.class };

    }

    @Override

    protected String getServletMappings() {

        return new String { "/" };

    }

}

I also created a controller :

package com.app.controller;



import java.util.List;



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

import org.springframework.stereotype.Controller;

import org.springframework.ui.Model;

import org.springframework.web.bind.annotation.GetMapping;

import org.springframework.web.bind.annotation.PathVariable;

import org.springframework.web.bind.annotation.PostMapping;

import org.springframework.web.bind.annotation.ResponseBody;



import com.app.dao.AdminsRepository;

import com.app.model.Admin;



@SuppressWarnings("unused")

@Controller

public class AdminsController {



    @Autowired

    private AdminsRepository adminsRepository;



    @GetMapping("/admins")

    @ResponseBody

    public String getAllAdmins(Model model) {

        return adminsRepository.findAll().toString();

    }



    @GetMapping("/admin/{id}")

    @ResponseBody

    public String getAdmin(@PathVariable("id") int id, Model model) {

        return adminsRepository.findById((long) id).orElse(null).toString();

    }

    @PostMapping("/admin")

    @ResponseBody

    public String createAdmin(Admin admin, Model model) {

        System.out.println(admin);

        return adminsRepository.save(admin).toString(); 

    }

}

The repository :

package com.app.dao;



//import java.util.List;

import org.springframework.data.jpa.repository.JpaRepository;

import org.springframework.stereotype.Repository;



import com.app.model.Admin;



@Repository

public interface AdminsRepository extends JpaRepository <Admin, Long>{ }

And my model :

package com.app.model;



import java.io.Serializable;

import javax.persistence.*;



import java.sql.Timestamp;

import java.util.List;



@Entity

@Table(name="admins")

@NamedQuery(name="Admin.findAll", query="SELECT a FROM Admin a")

public class Admin implements Serializable {

    private static final long serialVersionUID = 1L;



    @Id

    private int id;



    @Column(name="created_at")

    private Timestamp createdAt;



    private String email;

    private String login;

    private String password;

    private String name;

    private String surname;

    // ... getters and setters + delegated methods 

}

When I start running the application and open the browser I receive an error message:

No qualifying bean of type 'com.app.dao.AdminsRepository' available:

expected at least 1 bean which qualifies as autowire candidate. Dependency annotations:

{@org.springframework.beans.factory.annotation.Autowired(required=true)}

G'day David,

Just breaking down the answer moiljter already gave you.

You can only @Autowire objects that are declared in packages being scanned for components.

Currently, your @ComponentScan annotation only includes your controller package:

@ComponentScan("com.app.controller")

Broaden the search slightly like so:

@ComponentScan("com.app")

Then it should pick up your AdminsRepository and hum nicely.

Cheers,

ALS

You need to add "com.app.dao" to the list of packages that Spring will scan for components (and maybe also "com.app.model" if any of those annotations are Spring ones), or just change it to scan "com.app" (which will include everything in your app.