整合SpringMVC

public class WebInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
    // 指定根容器配置类，在Spring容器中创建，具有唯一性
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[] { RootConfig.class };
    }
    // 指定Web容器配置类，在SpringMVC容器中创建，可以有多个
    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[] {WebConfig.class};
    }
    // 指定映射路径
    @Override
    protected String[] getServletMappings() {
        // 设置DispatcherServlet的映射路径
        return new String[] {"/"};
    }
    // 指定过滤器
    @Override
    protected Filter[] getServletFilters() {
        // 注册字符编码过滤器
        CharacterEncodingFilter encodingFilter = new CharacterEncodingFilter();
        encodingFilter.setEncoding("UTF-8");
        encodingFilter.setForceEncoding(true);
        return new Filter[] {encodingFilter};
    }
}

@Configuration
@EnableTransactionManagement
@PropertySource("classpath:jdbc.properties")
@ComponentScan(
        basePackages = "com.example",
        excludeFilters = @ComponentScan.Filter(type = FilterType.ANNOTATION, value = Controller.class)
)
public class RootConfig {
    @Resource
    private Environment env;
    // 配置数据连接
    @Bean
    public DataSource dataSource() {
        DruidDataSource dataSource = new DruidDataSource();
        dataSource.setDriverClassName(env.getProperty("jdbc.driverClass"));
        dataSource.setUrl(env.getProperty("jdbc.url"));
        dataSource.setUsername(env.getProperty("jdbc.username"));
        dataSource.setPassword(env.getProperty("jdbc.password"));
        return dataSource;
    }
    // 配置数据模板
    @Bean
    public JdbcTemplate jdbcTemplate() {
        return new JdbcTemplate(dataSource());
    }
    // 配置事务管理器
    @Bean
    public PlatformTransactionManager transactionManager() {
        return new DataSourceTransactionManager(dataSource());
    }
    // 配置事务模板
    @Bean
    public TransactionTemplate transactionTemplate() {
        return new TransactionTemplate(transactionManager());
    }
}

@Configuration
@EnableWebMvc
@ComponentScan("com.example.controller")
public class WebConfig implements WebMvcConfigurer {
    // 配置JSP视图解析器
    @Bean
    public ViewResolver viewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        resolver.setContentType("text/html;charset=UTF-8");
        return resolver;
    }
    // 配置静态资源处理
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**")
                .addResourceLocations("/static/");
    }
    // 配置消息转换器，设置编码格式
    @Override
    public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        // 遍历消息转换器列表
        for (int i = 0; i < converters.size(); i++) {
            // 修改原始StringHttpMessageConverter转换器
            if (converters.get(i) instanceof StringHttpMessageConverter) {
                // 设置UTF-8编码
                StringHttpMessageConverter custom = new StringHttpMessageConverter(StandardCharsets.UTF_8);
                // 设置为false可以避免响应头过大
                custom.setWriteAcceptCharset(false);
                // 替换原始StringHttpMessageConverter转换器
                converters.set(i, custom);
                break;
            }
        }
    }
}

public class User {
    private Integer id;
    private String name;
    private Integer age;
    private String email;
    // ...
}

@Repository
public class UserDao {
    @Resource
    private JdbcTemplate jdbcTemplate;
    public List<User> selectUserList() {
        String sql = "SELECT id, name, age, email FROM user";
        return jdbcTemplate.query(sql, new BeanPropertyRowMapper<>(User.class));
    }
}

@Service
@Transactional
public class UserService {
    @Resource
    private UserDao userDao;
    public List<User> findUserList() {
        return userDao.selectUserList();
    }
}

@Controller
@RequestMapping("/user")
public class UserController {
    @Resource
    private UserService userService;
    // 跳转到用户列表页面
    @GetMapping("/page")
    public String page() {
        return "user";
    }
    // 获取所有用户
    @GetMapping("/list")
    @ResponseBody
    public List<User> list() {
        return userService.findUserList();
    }
}