SSM整合02_纯注解方式

本教程源码请访问：tutorial_demo

SSM整合可以使用多种方式，我们纯注解的方式，抛弃所有的xml配置文件（包括web.xml），使用Java配置类和注解进行配置。

SSM的整体思路：整合Spring和SpringMVC，整合Spring和MyBatis，两两整合。

一、环境准备

1.1、建库建表

DROP DATABASE IF EXISTS ssm;
CREATE DATABASE ssm;
USE ssm;


DROP TABLE IF EXISTS account;
CREATE TABLE account (
  id int(11) NOT NULL AUTO_INCREMENT,
  name varchar(40) DEFAULT NULL,
  money float DEFAULT NULL,
  PRIMARY KEY (id)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8mb4;

INSERT INTO account VALUES ('1', 'Tom', '1999');
INSERT INTO account VALUES ('2', 'Bob', '2000');
INSERT INTO account VALUES ('3', 'Peter', '10000');
INSERT INTO account VALUES ('5', 'John', '9700');
INSERT INTO account VALUES ('6', 'Smith', '421315');
INSERT INTO account VALUES ('7', 'Rose', '8800000');

1.2、创建Maven工程

在idea中从原型创建Maven工程，选择org.apache.maven.archetypes:maven-archetype-webapp，在pom.xml中添加如下的坐标：

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-tx</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-test</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.9.5</version>
</dependency>
<!-- Spring和MyBatis整合的jar包 -->
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.3</version>
</dependency>
<dependency>
    <groupId>c3p0</groupId>
    <artifactId>c3p0</artifactId>
    <version>0.9.1.2</version>
</dependency>
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.4.5</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.47</version>
</dependency>
<dependency>
    <groupId>log4j</groupId>
    <artifactId>log4j</artifactId>
    <version>1.2.17</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.2.6.RELEASE</version>
</dependency>
<!-- Servlet -->
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
</dependency>
<!-- JSP -->
<dependency>
    <groupId>javax.servlet.jsp</groupId>
    <artifactId>jsp-api</artifactId>
    <version>2.0</version>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.9.0</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.9.0</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.9.0</version>
</dependency>
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>jstl</artifactId>
    <version>1.2</version>
</dependency>

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.13</version>
    <scope>test</scope>
</dependency>

这里注意，由于我们要抛弃web.xml配置文件，需要将servlet版本升级到3.0及以上版本。

1.3、创建实体类

package org.codeaction.bean;

/**
 * 表示账户的实体类
 */
public class Account {
    private Integer id;
    private String name;
    private Float money;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public Float getMoney() {
        return money;
    }

    public void setMoney(Float money) {
        this.money = money;
    }

    @Override
    public String toString() {
        return "Account{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", money=" + money +
                '}';
    }
}

1.4、创建持久层接口

package org.codeaction.dao;

import org.codeaction.bean.Account;
import java.util.List;

public interface IAccountDao {
    List<Account> findAll();
}

1.5、创建业务层接口

package org.codeaction.service;

import org.codeaction.bean.Account;

import java.util.List;

public interface IAccountService {
    List<Account> findAll();
}

二、SSM整合

2.1、保证Spring框架在Web工程中独立运行

2.1.1、编写Spring配置类

这个配置类用来对Spring进行配置，代替之前的Spring配置文件applicationContext.xml。

//Spring的配置类
@Configuration
@ComponentScan(value = "org.codeaction",
		excludeFilters = {
        		@ComponentScan.Filter(
					type = FilterType.ANNOTATION,
					classes = {org.springframework.stereotype.Controller.class})
})
public class RootConfig {

}  

@Configuration声明这是一个配置类。

@ComponentScan指定要扫描的包，excludeFilters指定要忽略的注解，因为@Controller配置的类由SpringMVC管理，Spring要忽略它。

2.1.2、创建持久层接口的实现类

package org.codeaction.dao.impl;

import org.codeaction.bean.Account;
import org.codeaction.dao.IAccountDao;
import org.springframework.stereotype.Repository;

import java.util.List;

/**
 * 这个类仅仅用来测试Spring框架是否搭建成功，测试通过后就可以删掉
 */
@Repository
public class AccountDaoImpl implements IAccountDao {

    @Override
    public List<Account> findAll() {
        System.out.println("AccountDaoImpl----findAll");
        return null;
    }
}

这个类是一个“临时的类”，用来后面测试Spring框架是否搭建成功，后续可以删掉。

2.1.3、创建业务层接口的实现类

package org.codeaction.service.impl;

import org.codeaction.bean.Account;
import org.codeaction.dao.IAccountDao;
import org.codeaction.service.IAccountService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class AccountServiceImpl implements IAccountService {

    @Autowired
    private IAccountDao accountDao;

    @Override
    public List<Account> findAll() {
        return accountDao.findAll();
    }
}

2.1.4、测试Spring是否能够独立运行

package org.codeaction.test;

import org.codeaction.bean.Account;
import org.codeaction.service.IAccountService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class SpringTest {

    @Autowired
    private IAccountService accountService;

    @Test
    public void testSpring() {
        List<Account> list = accountService.findAll();
    }

}

运行测试方法，控制台输出如下，Spring配置成功

AccountDaoImpl----findAll

2.2、保证SpringMVC在Web工程中独立运行

2.2.1、编写SpringMVC的配置类

之前我们在springmvc.xml中配置SpringMVC，这里我们抛弃springmvc.xml，使用Java类配置SpringMVC。

package org.codeaction.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.web.servlet.config.annotation.*;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

//SpringMVC的配置类
@Configuration
@ComponentScan(value = "org.codeaction", includeFilters = {
        @ComponentScan.Filter(type = FilterType.ANNOTATION, classes = {org.springframework.stereotype.Controller.class})
})
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {

    //配置视图解析器
    @Override
    public void configureViewResolvers(ViewResolverRegistry registry) {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/pages/");
        resolver.setSuffix(".jsp");

        registry.viewResolver(resolver);
    }

    //配置静态资源不过滤
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/css/**").addResourceLocations("/css/");
        registry.addResourceHandler("/images/**").addResourceLocations("/images/");
        registry.addResourceHandler("/js/**").addResourceLocations("/js/");
    }
}

2.2.2、配置核心控制器

之前我们在web.xml中配置核心控制器，这里我们抛弃web.xml，使用Java类配置核心控制器。

package org.codeaction.config;

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

public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        //这里暂时先这样写，后面还要修改
        return new Class[]{};
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{WebConfig.class};
    }

    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
}

我们只需要知道继承AbstractAnnotationConfigDispatcherServletInitializer的类都会自动地配置DispatcherServlet和Spring应用上下文，Spring的应用上下文会位于应用程序的Servlet上下文之中。

在Servlet3.0环境中，容器会在类路径中查找实现javax.servlet.ServletContainerInitializer接口的类，如果能发现的话，就会用它来配置Servlet容器。

Spring提供了这个接口的实现，名为SpringServletContainerInitializer，SpringServletContainerInitializer这个类反过来又会查找实现WebApplicationInitializer的类并将配置的任务交给它们来完成。Spring3.2引入了WebApplicationInitializer的基础实现AbstractAnnotationConfigDispatcherServletInitializer。

因此，我们继承AbstractAnnotationConfigDispatcherServletInitializer（同时也实现了WebApplicationInitializer），当项目部署到Servlet3.0容器中的时候，容器会自动发现它，并用它来配置Servlet上下文。

getServletMappings()会将一个或多个路径映射到DispatcherServlet上。

getServletConfigClasses()在DispatcherServlet加载应用上下文时，使用定义在WebConfig配置类中的bean。WebConfig作用就是代替springmvc.xml配置文件，getServletConfigClasses()说白了就是让DispatcherServlet读取springmvc.xml的配置用的。

我们在之前Spring整合SpringMVC中需要配置监听器ContextLoaderListener，并且要将Spring的配置文件当成初始化参数进行配置供ContextLoaderListener读取，getRootConfigClasses()作用和这个相同，就是指定Spring的配置类，供监听器ContextLoaderListener读取，后面我们会用到，这个数组我们暂时不写内容。

2.2.3、编写Controller

package org.codeaction.controller;

import org.codeaction.bean.Account;
import org.codeaction.service.IAccountService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServletRequest;
import java.util.List;

@Controller
public class AccountController {

    @RequestMapping("/accounts")
    public String findAll(Model m) {
        System.out.println("findAll...");
        return "success";
    }
}

2.2.4、编写JSP页面

index.jsp，在webapp目录下

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>Index</title>
</head>
<body>
    <p>
        <a href="${pageContext.request.contextPath}/accounts">查询所有</a>
    </p>
</body>
</html>

success.jsp，在webapp\WEB-INF\pages目录下

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<html>
<head>
    <title>success</title>
</head>
<body>
    <p>success...</p>
</body>
</html>

运行tomcat服务器，访问index.jsp上的超链接，能够跳转到success.jsp，说明SpringMVC配置成功。

2.3、保证MyBatis在Web工程中独立运行

2.3.1、修改持久层接口

这里可以把先前创建的持久层接口的实现类删除了。

package org.codeaction.dao;

import org.apache.ibatis.annotations.Select;
import org.codeaction.bean.Account;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface IAccountDao {
    @Select("select * from account")
    List<Account> findAll();
}

2.3.2、编写jdbc配置文件

文件名：jdbc.properties；

位置：resources目录下。

jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql://localhost:3306/ssm?characterEncoding=utf8
jdbc.user=root
jdbc.password=123456

2.3.3、编写MyBatis配置文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<!-- mybatis的主配置文件 -->
<configuration>
    <properties resource="jdbc.properties"></properties>
    <!-- 配置环境 -->
    <environments default="mysql">
        <!-- 配置mysql的环境 -->
        <environment id="mysql">
            <!-- 配置事务的类型 -->
            <transactionManager type="JDBC"></transactionManager>
            <!-- 配置数据源连接池-->
            <dataSource type="POOLED">
                <!--
    				配置连接数据库的4个基本信息
    				通过${属性名}的方式获取属性值
    			-->
                <property name="driver" value="${jdbc.driverClass}"/>
                <property name="url" value="${jdbc.jdbcUrl}"/>
                <property name="username" value="${jdbc.user}"/>
                <property name="password" value="${jdbc.password}"/>
            </dataSource>
        </environment>
    </environments>

    <!-- 指定映射配置文件的位置 -->
    <mappers>
        <package name="org.codeaction.dao"/>
    </mappers>
</configuration>

2.3.4、测试MyBatis是否能够独立运行

package org.codeaction.test;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.codeaction.bean.Account;
import org.codeaction.dao.IAccountDao;
import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.util.List;

public class MyBatisTest {
    @Test
    public void testMyBatis() throws IOException {
        InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml");
        SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);
        SqlSession session = factory.openSession();

        IAccountDao accountDao = session.getMapper(IAccountDao.class);
        List<Account> accounts = accountDao.findAll();
        accounts.forEach(System.out::println);
    }
}

运行测试方法，控制台输出如下：

Account{id=1, name='Tom', money=1999.0}
Account{id=2, name='Bob', money=2000.0}
Account{id=3, name='Peter', money=10000.0}
Account{id=5, name='John', money=9700.0}
Account{id=6, name='Smith', money=421315.0}
Account{id=7, name='Rose', money=8800000.0}

2.4、整合Spring和SpringMVC

修改WebAppInitializer，代码如下：

package org.codeaction.config;

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

import javax.servlet.FilterRegistration;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;

public class WebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        //让监听器加载Spring的配置
        return new Class[]{RootConfig.class};
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{WebConfig.class};
    }

    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

    //配置POST请求编码的Filter
    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
        super.onStartup(servletContext);
        FilterRegistration.Dynamic characterEncodingFilter = servletContext.addFilter("characterEncodingFilter", new CharacterEncodingFilter());
        characterEncodingFilter.setInitParameter("encoding", "UTF-8");
        characterEncodingFilter.addMappingForUrlPatterns(null, false, "/*");
    }
}

通过onStartup可以在SpringMVC中配置Servlet、Filter、Listener。

2.5、整合Spring和MyBatis

2.5.1、编写数据源配置类

package org.codeaction.config;

import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;

/**
 * 配置类
 */
@Configuration
public class JdbcConfig {
    @Value("${jdbc.driverClass}")
    private String driverClass;
    @Value("${jdbc.jdbcUrl}")
    private String jdbcUrl;
    @Value("${jdbc.user}")
    private String user;
    @Value("${jdbc.password}")
    private String password;

    //创建和配置数据源
    @Bean("dataSource")
    public DataSource dataSource() {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        try {
            dataSource.setDriverClass(driverClass);
            dataSource.setJdbcUrl(jdbcUrl);
            dataSource.setUser(user);
            dataSource.setPassword(password);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return dataSource;
    }
}

2.5.2、编写事务配置类

package org.codeaction.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import org.springframework.transaction.PlatformTransactionManager;

import javax.sql.DataSource;

@Configuration
public class TransactionConfig {
    //创建事务管理器
    @Bean("transactionManager")
    public PlatformTransactionManager transactionManager(DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
}

2.5.3、修改Spring配置类

package org.codeaction.config;


import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.*;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import javax.sql.DataSource;

//Spring的配置类
@Configuration
@ComponentScan(value = "org.codeaction", excludeFilters = {
        @ComponentScan.Filter(type = FilterType.ANNOTATION, classes = {org.springframework.stereotype.Controller.class})
})
@PropertySource("classpath:jdbc.properties")
@Import({JdbcConfig.class, TransactionConfig.class})
@EnableTransactionManagement
@MapperScan(basePackages = "org.codeaction.dao")
public class RootConfig {

    //配置MyBatis的Bean工厂
    @Bean("sqlSessionFactory")
    public SqlSessionFactoryBean sqlSessionFactoryBean(DataSource dataSource) {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource);

        return sqlSessionFactoryBean;
    }
}

@MapperScan指定Spring要扫描的Mapper的位置。

通过上面的配置，Spring容器负责MyBatis Session工厂的创建，接下来就可以把MyBatis的主配置文件SqlMapConfig.xml删除了。

2.5.4、修改持久层接口

package org.codeaction.dao;

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import org.codeaction.bean.Account;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper
public interface IAccountDao {
    @Select("select * from account")
    List<Account> findAll();
}

2.6、整体测试

2.6.1、修改Controller

package org.codeaction.controller;

import org.codeaction.bean.Account;
import org.codeaction.service.IAccountService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.servlet.http.HttpServletRequest;
import java.util.List;

@Controller
public class AccountController {

    @Autowired
    private IAccountService accountService;

    @RequestMapping("/accounts")
    public String findAll(Model m) {
        List<Account> accounts = accountService.findAll();
        m.addAttribute("accounts", accounts);
        return "success";
    }
}

2.6.2、修改success.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
    <title>success</title>
</head>
<body>
    <p>success...</p>
    <table>
        <tr>
            <th>id</th>
            <th>姓名</th>
            <th>余额</th>
        </tr>
        <c:forEach items="${accounts}" var="item">
            <tr>
                <td>${item.id}</td>
                <td>${item.name}</td>
                <td>${item.money}</td>
            </tr>
        </c:forEach>
    </table>
</body>
</html>

2.6.3、测试

运行tomcat服务器，点击index.jsp上的超链接，最终页面显示表格，表格中显示数据库account表的数据，测试通过。