Spring的纯注解配置

2024-01-16 21:06:02
开发
29

新注解说明

@Configuration

作用：用于指定当前类是一个spring配置列，可替换xml配置文件，作用和在spring的xml配置文件的：< beans></ beans>是一样的
示例代码

/**
 * spring的配置类
 */
@Configuration//等价于<beans>，当从一个类上加载到该注解时会创建spring容器
public class SpringConfiguration{
   
}

@ComponentScan

作用：
用于指定spring在初始化容器时要扫描的包。作用和在spring的xml配置文件中的< contextLcomponent-scan base-package=“com.by”/>是一样的
属性：
basePackages:用于指定要扫描的包。和该注解中的value属性作用一样
示例代码：

/**
 * spring的配置类
 */
@Configuration
@ComponentScan(basePackages = "com.by")//等价于<context:component-scan>
public class SpringConfiguration{
   
}

@Bean

作用：

该注解只能写在方法上，表明使用此方法创建一个对象，并且放入spring容器。作用和在spring的xml配置文件中的：<bean/>是一样的。
属性：

name：给当前@Bean注解方法创建的对象指定一个名称(即bean的id）。

示例代码

public class Dog {
     
    private String nam;
    private Integer age;
	//set get......
}

@Bean
public Dog dog(){
     
    Dog dog = new Dog();
    dog.setNam("二狗");
    dog.setAge(18);
    return dog;
}

@PropertySource

作用：

用于加载*.properties文件中的配置。作用和在spring的xml配置文件中的：<context:property-placeholder location="">是一样的。
属性：

value[]：用于指定properties文件位置。如果是在类路径下，需要写上classpath:

示例代码

#config.properties
nam=二狗
age=18

@PropertySource("classpath:config.properties")
public class SpringConfiguration {
     

    @Value("${nam}")
    private String nam;
    @Value("${age}")
    private Integer age;

    @Bean
    public Dog dog(){
     
        Dog dog = new Dog();
        dog.setNam(nam);
        dog.setAge(age);
        return dog;
    }
}

@Import

作用：

@Import注解是用来导入配置类或者一些需要前置加载的类。作用和在spring的xml配置文件中的：<import resource=""></import>是一样.
属性：

value[]：用于指定其他配置类的字节码。

示例代码

@Configuration
@ComponentScan(basePackages = "com.by")
@Import({
     Configuration_Other.class})
public class SpringConfiguration {
     

}

@PropertySource("classpath:config.properties")
public class Configuration_Other {
     

}

Spring的纯注解配置

JdbcConfig

import com.alibaba.druid.pool.DruidDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.PropertySource;
import javax.sql.DataSource;
 
@PropertySource("classpath:db.properties")
public class JdbcConfig {
   
    @Value("${jdbc.driver}")
    private String driver;
    @Value("${jdbc.url}")
    private String url;
    @Value("${jdbc.username}")
    private String userName;
    @Value("${jdbc.password}")
    private String password;

    @Bean("dataSource")
    public DataSource getDatasource() {
   
        DruidDataSource ds = new DruidDataSource();
        ds.setDriverClassName(driver);
        ds.setUrl(url);
        ds.setUsername(userName);
        ds.setPassword(password);
        return ds;
    }
}

MybatisConfig

import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.mapper.MapperScannerConfigurer;
import org.springframework.context.annotation.Bean;
 
import javax.sql.DataSource;
 
public class MyBatisConfig {
   
    @Bean
    public SqlSessionFactoryBean getSqlSessionFactoryBean(
             DataSource dataSource){
   
        SqlSessionFactoryBean ssfb=new SqlSessionFactoryBean();
        ssfb.setDataSource(dataSource);
        ssfb.setTypeAliasesPackage("com.by.pojo");
        return ssfb;
    }
    @Bean
    public MapperScannerConfigurer getMapperScannerConfigurer(){
   
        MapperScannerConfigurer msc=new MapperScannerConfigurer();
        msc.setBasePackage("com.by.mapper");
        return msc;
    }
}

TxConfig

import org.springframework.context.annotation.Bean;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;
import javax.sql.DataSource;

public class TxConfig {
   

    @Bean
    public PlatformTransactionManager transactionManager(DataSource dataSource){
   
        DataSourceTransactionManager ds = new DataSourceTransactionManager();
        ds.setDataSource(dataSource);
        return ds;
    }
}

SpringConfig

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@Import({
   MyBatisConfig.class, JdbcConfig.class, TxConfig.class})
//等同<context:component-scan base-package="com.by"/>`
@ComponentScan(value = "com.by.service")
//等同于<tx:annotation-driven />，bean的名称默认取transactionManager
@EnableTransactionManagement
public class SpringConfig {
   
 
}

SpringMvcConfig

import com.by.converter.MyDateConverter;
import com.by.interceptor.LoginInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.format.FormatterRegistry;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
//等同于<context:component-scan base-package="com.by.controller>
@ComponentScan("com.by.controller")
//等同于<mvc:annotation-driven></mvc:annotation-driven>
@EnableWebMvc
public class SpringMvcConfig implements WebMvcConfigurer {
   

    @Bean
    public ViewResolver viewResolver() {
   
        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
        viewResolver.setPrefix("/WEB-INF/pages/"); // 设置视图文件所在目录
        viewResolver.setSuffix(".jsp"); // 设置视图文件后缀名
        return viewResolver;
    }

    @Bean
    public CommonsMultipartResolver multipartResolver(){
   
        CommonsMultipartResolver commonsMultipartResolver=new CommonsMultipartResolver();
        return commonsMultipartResolver;
    }

    @Override
    public void addFormatters(FormatterRegistry registry) {
   
        registry.addConverter(new MyDateConverter());
    }

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
   
        registry.addInterceptor(new LoginInterceptor()).addPathPatterns("/emp/**");
    }

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

WebConfig

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

import javax.servlet.Filter;

/**
 * 当类扩展了AbstractAnnotationConfigDispatcherServletlnitializer并将其部署到 Servlet容器时，
 * 容器会自动发现它，并用它来配置Servlet环境
 */
public class WebConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
   
    
    //加载Spring配置类
    protected Class<?>[] getRootConfigClasses() {
   
        return new Class[]{
   SpringConfig.class};
    }
    
    //加载SpringMVC配置类
    protected Class<?>[] getServletConfigClasses() {
   
        return new Class[]{
   SpringMvcConfig.class};
    }
    
    //设置SpringMVC请求地址拦截规则
    protected String[] getServletMappings() {
   
        return new String[]{
   "/"};
    }
    
    //设置post请求中文乱码过滤器
    @Override
    protected Filter[] getServletFilters() {
   
        CharacterEncodingFilter filter = new CharacterEncodingFilter();
        filter.setEncoding("utf-8");
        return new Filter[]{
   filter};
    }
}

删除xml配置文件

修改web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">
    <welcome-file-list>
        <welcome-file>login.jsp</welcome-file>
    </welcome-file-list>
</web-app>

最后测试

原文地址:https://blog.csdn.net/w2144217940/article/details/135623329 本文来自互联网用户投稿，该文观点仅代表作者本人，不代表本站立场。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如若转载，请注明出处：https://www.suanlizi.com/kf/1747243812666871808.html 如若内容造成侵权/违法违规/事实不符，请联系《酸梨子》网邮箱：1419361763@qq.com进行投诉反馈，一经查实，立即删除！

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