如何用配置类的方式搭建spring boot+JPA+thymeleaf框架

为什么要使用配置类

一般情况下spring boot的自动配置已经能够满足应用需求，因此可以看到很多spring boot项目只用配置文件，没用配置类。不过要想精确控制应用，或者覆盖自动配置，就应该使用配置类和文件配置互补的方式。

集成JPA

首先是必要的maven配置

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
</dependency>

这里用的是Mysql数据库

配置文件中JPA的相关配置

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/test
spring.datasource.username=root
spring.datasource.password=12345
spring.jpa.database = MYSQL
spring.jpa.show-sql=true
spring.jpa.hibernate.ddl-auto=validate

编写JPA的配置类

import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.jca.support.LocalConnectionFactoryBean;
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.transaction.annotation.EnableTransactionManagement;

import javax.persistence.EntityManagerFactory;
import javax.sql.DataSource;


@Configuration
@EnableJpaRepositories(basePackages = "com.imooc.repository")
@EnableTransactionManagement
public class JPAConfig {
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource")
    public DataSource datasource() {
        return DataSourceBuilder.create().build();
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        HibernateJpaVendorAdapter jpaVendor = new HibernateJpaVendorAdapter();
        jpaVendor.setGenerateDdl(false);

        LocalContainerEntityManagerFactoryBean entityManagerFactory = new LocalContainerEntityManagerFactoryBean();
        entityManagerFactory.setDataSource(datasource());
        entityManagerFactory.setJpaVendorAdapter(jpaVendor);
        entityManagerFactory.setPackagesToScan("com.imooc.entity");
        return entityManagerFactory;
    }

    @Bean
    public PlatformTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactory);
        return transactionManager;

    }
}

创建一个实体类

package com.imooc.entity;

import javax.persistence.*;
import java.util.Date;


@Entity
@Table(name = "user")
public class User {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;

    private String password;

    private String email;

    @Column(name = "phone_number")
    private String phoneNumber;

    private int status;

    @Column(name = "create_time")
    private Date createTime;

    @Column(name = "last_login_time")
    private Date lastLoginTime;

    private String avatar;

    public Long getId() {
        return id;
    }

    public User setId(Long id) {
        this.id = id;
        return this;
    }

    public String getName() {
        return name;
    }

    public User setName(String name) {
        this.name = name;
        return this;
    }

    public String getPassword() {
        return password;
    }

    public User setPassword(String password) {
        this.password = password;
        return this;
    }

    public String getEmail() {
        return email;
    }

    public User setEmail(String email) {
        this.email = email;
        return this;
    }

    public String getPhoneNumber() {
        return phoneNumber;
    }

    public User setPhoneNumber(String phoneNumber) {
        this.phoneNumber = phoneNumber;
        return this;
    }

    public int getStatus() {
        return status;
    }

    public User setStatus(int status) {
        this.status = status;
        return this;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public User setCreateTime(Date createTime) {
        this.createTime = createTime;
        return this;
    }

    public Date getLastLoginTime() {
        return lastLoginTime;
    }

    public User setLastLoginTime(Date lastLoginTime) {
        this.lastLoginTime = lastLoginTime;
        return this;
    }

    public String getAvatar() {
        return avatar;
    }

    public User setAvatar(String avatar) {
        this.avatar = avatar;
        return this;
    }
}

定义Repository接口

public interface UserRepository extends CrudRepository

写个测试类测试一下

public class UserRepositoryTest extends DemoApplicationTests {
    @Autowired
    private UserRepository userRepository;

    @Test
    public void testFindOne() {
        User user = userRepository.findOne(1L);
        Assert.assertEquals("wali", user.getName());
    }
}

集成前端框架thymeleaf

maven配置

<properties>
        <thymeleaf.version>3.0.3.RELEASE</thymeleaf.version>
        <thymeleaf-layout-dialect.version>2.1.1</thymeleaf-layout-dialect.version>
        <thymeleaf-extras-springsecurity4.version>3.0.2.RELEASE</thymeleaf-extras-springsecurity4.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

        <dependency>
            <groupId>org.thymeleaf</groupId>
            <artifactId>thymeleaf</artifactId>
            <version>${thymeleaf.version}</version>
        </dependency>
        <dependency>
            <groupId>org.thymeleaf</groupId>
            <artifactId>thymeleaf-spring4</artifactId>
            <version>3.0.2.RELEASE</version>
        </dependency>

配置文件中thymeleaf的相关配置

spring.thymeleaf.mode=HTML
spring.thymeleaf.suffix=.html
spring.thymeleaf.prefix=classpath:/templates/

注意，此处有坑听说suffix 和prefix是spring boot默认的不配也可以，结果就是前端资源怎么都找不到。最后配上就好了。。。

mvc相关的配置类

import org.springframework.beans.BeansException;
import org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.thymeleaf.spring4.SpringTemplateEngine;
import org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver;
import org.thymeleaf.spring4.view.ThymeleafViewResolver;


@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter implements ApplicationContextAware {
    private ApplicationContext applicationContext;
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");
    }

    @Bean
    @ConfigurationProperties(prefix = "spring.thymeleaf")
    public SpringResourceTemplateResolver templateResolver() {
        SpringResourceTemplateResolver templateResolver = new SpringResourceTemplateResolver();
        templateResolver.setApplicationContext(this.applicationContext);
        return templateResolver;
    }

    @Bean
    public SpringTemplateEngine templateEngine() {
        SpringTemplateEngine templateEngine = new SpringTemplateEngine();
        templateEngine.setTemplateResolver(templateResolver());
        templateEngine.setEnableSpringELCompiler(true);
        return templateEngine;
    }

    @Bean
    public ThymeleafViewResolver viewResolver() {
        ThymeleafViewResolver viewResolver = new ThymeleafViewResolver();
        viewResolver.setTemplateEngine(templateEngine());
        return  viewResolver;
    }
}

写个简单的前端页面

src\main\resources\templates\index.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Xunwu</title>
</head>
<body>
Hello,wei
<span th:text="${name}"></span>
</body>
</html>

写个controller 测试一波

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;


@Controller
public class HomeController {
    @GetMapping("/")
    public String index(Model model) {
        model.addAttribute("name", "ddd");
        return "index";
    }
}