springboot零配置

使用模板创建一个普通的Maven的Web项目

1.引jar包

<dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.3.6</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>5.3.14</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.3.14</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/com.mchange/c3p0 -->
    <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.5.5</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.47</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.7</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>2.0.6</version>
    </dependency>
​
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
    </dependency>
  </dependencies>

2.书写application.properties

spring.datasource.driver=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test2
spring.datasource.username=root
spring.datasource.password=123456

3.书写实体类读取配置文件的值

package com.zhuoyue.config;
​
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
​
import java.util.Objects;
​
@Configuration
@PropertySource("classpath:application.properties")
public class DataSourceProperties {
    @Value("${spring.datasource.driver}")
    private String driver;
    @Value("${spring.datasource.url}")
    private String url;
    @Value("${spring.datasource.username}")
    private String username;
    @Value("${spring.datasource.password}")
    private String password;
​
    public String getDriver() {
        return driver;
    }
​
    public void setDriver(String driver) {
        this.driver = driver;
    }
​
    public String getUrl() {
        return url;
    }
​
    public void setUrl(String url) {
        this.url = url;
    }
​
    public String getUsername() {
        return username;
    }
​
    public void setUsername(String username) {
        this.username = username;
    }
​
    public String getPassword() {
        return password;
    }
​
    public void setPassword(String password) {
        this.password = password;
    }
​
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        DataSourceProperties that = (DataSourceProperties) o;
        return Objects.equals(driver, that.driver) && Objects.equals(url, that.url) && Objects.equals(username, that.username) && Objects.equals(password, that.password);
    }
​
    @Override
    public int hashCode() {
        return Objects.hash(driver, url, username, password);
    }
​
    @Override
    public String toString() {
        return "DataSourceProperties{" +
                "driver='" + driver + '\'' +
                ", url='" + url + '\'' +
                ", name='" + username + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}
​

3.创建配置类SpringBootConfig继承AbstractAnnotationConfigDispatcherServletInitializer

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
​
public class SpringBootConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[0];
    }
​
    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[0];
    }
​
    @Override
    protected String[] getServletMappings() {
        return new String[0];
    }
}
​

4.书写数据库配置

​
import com.mchange.v2.c3p0.ComboPooledDataSource;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.SqlSessionFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RestController;
​
import javax.sql.DataSource;
import java.beans.PropertyVetoException;
​
@Configuration
@MapperScan("com.zhuoyue.mapper")
@ComponentScan(
        basePackages = {"com.zhuoyue"},
        excludeFilters = {
                @ComponentScan.Filter(type = FilterType.ANNOTATION,value = {Controller.class, RestController.class})
        }
)
public class BaseConf {
​
    @Autowired
    DataSourceProperties dp;
    @Bean(value = "dataSources")
    public DataSource dataSource() throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass(dp.getDriver());
        dataSource.setJdbcUrl(dp.getUrl());
        dataSource.setUser(dp.getUsername());
        dataSource.setPassword(dp.getPassword());
        return dataSource;
    }
    @Bean
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource());
        return sqlSessionFactoryBean.getObject();
    }
}

5.书写Web配置

​
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
​
@Configuration
@EnableWebMvc
@ComponentScan(
        basePackages = {"com.zhuoyue"},
        includeFilters = {
                @ComponentScan.Filter(type = FilterType.ANNOTATION,value = {Controller.class, RestController.class})
        }
)
public class WebConf implements WebMvcConfigurer {
    @Bean
    public InternalResourceViewResolver view(){
        InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
        viewResolver.setPrefix("/");
        viewResolver.setSuffix(".jsp");
        return viewResolver;
    }
}

6.修改配置类SpringBootConfig

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
​
public class SpringBootConfig extends AbstractAnnotationConfigDispatcherServletInitializer {
    //数据库相关
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[]{BaseConf.class};
    }
    //web 类
    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[]{WebConf.class};
    }
​
    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
}

测试：

新建DeptPO

​
public class DeptPO {
    private Long deptno;
    private String dname;
    private String loc;
​
    public DeptPO(Long deptno, String dname, String loc) {
        this.deptno = deptno;
        this.dname = dname;
        this.loc = loc;
    }
​
    public DeptPO() {
    }
​
    public Long getDeptno() {
        return deptno;
    }
​
    public void setDeptno(Long deptno) {
        this.deptno = deptno;
    }
​
    public String getDname() {
        return dname;
    }
​
    public void setDname(String dname) {
        this.dname = dname;
    }
​
    public String getLoc() {
        return loc;
    }
​
    public void setLoc(String loc) {
        this.loc = loc;
    }
​
    @Override
    public String toString() {
        return "DeptPO{" +
                "deptno=" + deptno +
                ", dname='" + dname + '\'' +
                ", loc='" + loc + '\'' +
                '}';
    }
}

新建DeptMapper


import com.zhuoyue.po.DeptPO;
import org.apache.ibatis.annotations.Select;

import java.util.List;

public interface DeptMapper {

    @Select("select * from dept")
    List<DeptPO> findAll();
}

新建DeptController

import com.zhuoyue.po.DeptPO;
import org.apache.ibatis.annotations.Select;

import java.util.List;

public interface DeptMapper {

    @Select("select * from dept")
    List<DeptPO> findAll();
}