SpringMVC学习笔记

手写框架篇
- 需求分析
- 自定义SpringMVC框架V1版本
- - 定义处理器
  - 定义处理器映射器
  - 定义处理器适配器
  - 定义前端控制器
  - 配置web.xml
- 自定义SpringMVC框架V2版本
- - 修改自定义Spring框架整合
  - 修改处理器映射器
  - 修改前端控制器
  - 测试
- 自定义SpringMVC框架V3版本
- - 自定义注解
  - 定义RequestMappingHandlerMapping
  - 定义RequestMappingHandlerAdapter
  - DispatcherServlet.properties新增配置
  - 测试
- 代码实现github地址

手写框架篇

需求分析

需求：

* 查询用户：请求URL http://localhost/queryUser
* 添加用户：请求URL http://localhost/savaUser

问题：如果按照常规Servlet开发习惯，一个类只会处理一个请求。
解决方案：自定义Servlet extends BaseServlet（公共的Servlet）

BaseServlet{
     doPost(){
         // url中必须带有method参数
         // method参数的值就是对应要调用的方法名称
         // 通过反射调用制定方法
     }
}

MyServlet extends BaseServlet{
   query(){
   }
   save(){
   }
}

只需要一个Servlet进行请求分发即可，处理请求的类只是一个普通类（不需要实现Servlet相关的类）

自定义SpringMVC框架V1版本

定义处理器

处理器接口规范：

public interface HttpRequestHandler {
    void handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;
}

/**
 * 可以针对返回值进行二次处理
 */
public interface SimpleControllertHandler {
    ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;
}

处理器实现类：

/**
 * 查询用户处理器
 */
public class QueryUserHandler implements HttpRequestHandler {
    @Override
    public void handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/plain;charset=utf-8");
        response.getWriter().write("--- QueryUserHandler ---");
    }
}

/**
 * 添加用户处理器
 */
public class SaveUserHandler implements SimpleControllertHandler {
    @Override
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/plain;charset=utf-8");
        response.getWriter().write("--- SaveUserHandler ---");
        return null;
    }
}

定义处理器映射器

处理器映射器接口规范：

/**
 * 它的实现类是用来建立请求和处理类的映射关系
 * 该接口的作用是提供对该映射关系的访问，比如说根据请求查找处理类
 */
public interface HandlerMapping {
    /**
     * 根据请求查找处理类
     */
    Object getHandler(HttpServletRequest request) throws Exception;
}

处理器映射器实现类：

/**
 * <bean name="/queryUser" class="QueryUserHandler的全路径"></bean>
 */
public class BeanNameUrlHandlerMapping implements HandlerMapping {
    private Map<String, Object> urlHandlers = new HashMap<>();

    public BeanNameUrlHandlerMapping() {
    	// TODO 暂时先写死
        this.urlHandlers.put("/queryUser", new QueryUserHandler());
    }

    @Override
    public Object getHandler(HttpServletRequest request) throws Exception {
        String uri = request.getRequestURI();

        return this.urlHandlers.get(uri);
    }
}

/**
 * <bean  class="内置的处理器类">
 *  <props>
 *      <prop key="url">类的全路径</prop>
 *  </props>
 * </bean>
 */
public class SimpleUrlHandlerMapping implements HandlerMapping {
    private Map<String, Object> urlHandlers = new HashMap<>();

    public SimpleUrlHandlerMapping() {
        // TODO 暂时先写死
        this.urlHandlers.put("/saveUser", new SaveUserHandler());
    }

    @Override
    public Object getHandler(HttpServletRequest request) throws Exception {
        String uri = request.getRequestURI();
        return this.urlHandlers.get(uri);
    }
}

定义处理器适配器

处理器适配器接口规范：

/**
 * 该接口是DispatcherServlet用来调用不同类型处理器的统一类型
 * HandlerAdapter和Handler类型是一对一的，就类似于某一个类型的电脑，对应一个统一的电源适配器
 */
public interface HandlerAdapter {
    /**
     * 用来匹配适配器和处理器
     */
    boolean supports(Object handler);

    /**
     * 调用不同类型的处理器完成请求处理
     */
    ModelAndView handleRequest(Object handler, HttpServletRequest request, HttpServletResponse response) throws Exception;
}

处理器适配器实现类：

public class HttpRequestHandlerAdapter implements HandlerAdapter {
    @Override
    public boolean supports(Object handler) {
        return (handler instanceof HttpRequestHandler);
    }

    @Override
    public ModelAndView handleRequest(Object handler, HttpServletRequest request, HttpServletResponse response) throws Exception {
        ((HttpRequestHandler) handler).handleRequest(request, response);
        return null;
    }
}

public class SimpleControllerHandlerAdapter implements HandlerAdapter {
    @Override
    public boolean supports(Object handler) {
        return (handler instanceof SimpleControllertHandler);
    }

    @Override
    public ModelAndView handleRequest(Object handler, HttpServletRequest request, HttpServletResponse response) throws Exception {
        return ((SimpleControllertHandler) handler).handleRequest(request, response);
    }
}

定义前端控制器

抽象的Servlet：

public abstract class AbstractServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doDispatch(request, response);
    }

    /**
     * 请求分发
     */
    public abstract void doDispatch(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException;
}

DispatcherServlet：

/**
 * springmvc提供的唯一的一个Servlet类
 */
public class DispatcherServlet extends AbstractServlet {
    /**
     * HandlerMapping的策略集合
     */
    private List<HandlerMapping> handlerMappings = new ArrayList<>();
    /**
     * HandlerAdapter的策略集合
     */
    private List<HandlerAdapter> handlerAdapters = new ArrayList<>();

    /**
     * servlet初始化
     */
    @Override
    public void init() throws ServletException {
        handlerMappings.add(new BeanNameUrlHandlerMapping());
        handlerMappings.add(new SimpleUrlHandlerMapping());

        handlerAdapters.add(new HttpRequestHandlerAdapter());
        handlerAdapters.add(new SimpleControllerHandlerAdapter());
    }

    @Override
    public void doDispatch(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        try {
            // 1、根据请求，查找对应的处理类
            // 问题1：处理类长啥样？（它和Servlet无关，可以随便写，只是说为了统一，最后指定规范[接口]）
            // 问题2：去哪找处理类？（也就是请求URL和处理类的关系在哪建立）
            Object handler = getHandler(request);
            if (handler == null) {
                return;
            }
            // 2、调用处理类的方法，执行请求处理，并返回处理结果
            HandlerAdapter ha = getHandlerAdapter(handler);
            if (ha == null) {
                return;
            }
            ha.handleRequest(handler, request, response);
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

    private Object getHandler(HttpServletRequest request) throws Exception {
        // 首先 处理类和请求之间 的映射关系可能存储在不同的地方（HandlerMapping）
        if (handlerMappings != null) {
            for (HandlerMapping hm : handlerMappings) {
                Object handler = hm.getHandler(request);
                if (handler != null) {
                    return handler;
                }
            }
        }
        return null;
    }

    private HandlerAdapter getHandlerAdapter(Object handler) {
        if (handlerAdapters != null) {
            // 遍历策略集合
            for (HandlerAdapter ha : handlerAdapters) {
                if (ha.supports(handler)) {
                    return ha;
                }
            }
        }
        return null;
    }
}

配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">
    <servlet>
        <servlet-name>dispatcherServlet</servlet-name>
        <servlet-class>com.yw.servlet.DispatcherServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

自定义SpringMVC框架V2版本

创建一个工程：springmvc-framework-custom，并引入之前手写的Spring框架：

<!-- 引入自定义的Spring框架 -->
<dependency>
  <groupId>com.yw.spring.framework</groupId>
  <artifactId>spring-framework-custom</artifactId>
  <version>1.0</version>
</dependency>

将V1版本中的处理器映射器、处理器适配器、前端控制器等复制到该工程下，如下图所示：

JavaEE 企业级分布式高级架构师（四）SpringMVC学习笔记（2）手写框架篇

修改自定义Spring框架整合

JavaEE 企业级分布式高级架构师（四）SpringMVC学习笔记（2）手写框架篇

新增标记接口：用于BeanFactory容器的注入

public interface Aware {
}
public interface BeanFactoryAware extends Aware {
    void setBeanFactory(BeanFactory beanFactory);
}

定义接口 InitializingBean：实现该接口可以在依赖注入与初始化Bean 之间完成一些事情

public interface InitializingBean {
    void afterPropertiesSet();
}

修改AbstractAutowiredCapableBeanFactory中的 initializeBean 方法：

public abstract class AbstractAutowiredCapableBeanFactory extends AbstractBeanFactory {
    // 省略...
    
    private void initializeBean(Object bean, BeanDefinition beanDefinition) {
        // 需要针对Aware接口标记的类进行特殊处理
        if (bean instanceof Aware) {
            if (bean instanceof BeanFactoryAware) {
                ((BeanFactoryAware) bean).setBeanFactory(this);
            }
        }
        // 可以进行InitializeBean接口的处理
        if (bean instanceof InitializingBean) {
            ((InitializingBean) bean).afterPropertiesSet();
        }
        ReflectUtils.invokeMethod(bean, beanDefinition.getInitMethod());
    }
}

修改 ListableBeanFactory 接口

/**
 * 对于Bean容器中的Bean可以进行集合操作或者说叫批量操作
 */
public interface ListableBeanFactory extends BeanFactory {
    /**
     * 可以根据指定类型获取它或者它实现类的对象
     */
    <T> List<T> getBeansByType(Class type);
}

修改 BeanDefinitionRegistry 接口：新增 getBeanDefinitions 方法

/**
 * 1、实现类是封装了BeanDefinition集合信息
 * 2、接口类是提供对于其封装的BeanDefinition信息进行添加和获取功能
 */
public interface BeanDefinitionRegistry {
    /**
     * 获取BeanDefinition
     */
    BeanDefinition getBeanDefinition(String beanName);

    /**
     * 注册BeanDefinition
     */
    void registerBeanDefinition(String beanName, BeanDefinition beanDefinition);

    /**
     * 获取BeanDefinition集合
     */
    List<BeanDefinition> getBeanDefinitions();
}

DefaultListableBeanFactory 实现 ListableBeanFactory，BeanDefinitionRegistry中的两个方法：

/**
 * 既是spring中的真正管理Bean实例的容器工厂
 * 同时又是管理BeanDefinition的BeanDefinition注册器
 */
public class DefaultListableBeanFactory extends AbstractAutowiredCapableBeanFactory
        implements BeanDefinitionRegistry, ListableBeanFactory {
    /**
     * 存储BeanDefinition的容器
     */
    private Map<String, BeanDefinition> beanDefinitions = new ConcurrentHashMap<>(128);

    @Override
    public BeanDefinition getBeanDefinition(String beanName) {
        return beanDefinitions.get(beanName);
    }

    @Override
    public void registerBeanDefinition(String beanName, BeanDefinition beanDefinition) {
        beanDefinitions.put(beanName, beanDefinition);
    }

    @Override
    public List<BeanDefinition> getBeanDefinitions() {
        List<BeanDefinition> results = new ArrayList<>();
        for (BeanDefinition bd : beanDefinitions.values()) {
            results.add(bd);
        }
        return results;
    }

    @Override
    public <T> List<T> getBeansByType(Class type) {
        List<T> results = new ArrayList<>();
        // 获取容器中所有的BeanDefinition，遍历每个BeanDefinition，取出来它的类型
        for (BeanDefinition bd : beanDefinitions.values()) {
            Class<?> clazzType = bd.getClazzType();
            // type如果是clazzType的父类型，则返回true
            if (type.isAssignableFrom(clazzType)) {
                results.add((T) getBean(bd.getBeanName()));
            }
        }
        return results;
    }
}

修改处理器映射器

BeanNameUrlHandlerMapping 增加实现 InitializingBean 和 BeanFactoryAware 两个接口：体现Spring框架和SpringMVC框架的整合

public class BeanNameUrlHandlerMapping implements HandlerMapping, InitializingBean, BeanFactoryAware {
    private Map<String, Object> urlHandlers = new HashMap<>();

    private DefaultListableBeanFactory beanFactory;

    public BeanNameUrlHandlerMapping() {
    }

    @Override
    public Object getHandler(HttpServletRequest request) throws Exception {
        String uri = request.getRequestURI();

        return this.urlHandlers.get(uri);
    }

    @Override
    public void afterPropertiesSet() {
        List<BeanDefinition> beanDefinitions = beanFactory.getBeanDefinitions();
        for (BeanDefinition bd : beanDefinitions) {
            String beanName = bd.getBeanName();
            if (beanName.startsWith("/")) {
                this.urlHandlers.put(beanName, beanFactory.getBean(beanName));
            }
        }
    }

    @Override
    public void setBeanFactory(BeanFactory beanFactory) {
        this.beanFactory = (DefaultListableBeanFactory) beanFactory;
    }
}

修改前端控制器

resources目录下新增 DispatcherServlet.properties 文件：

com.yw.springmvc.framework.mapping.HandlerMapping=com.yw.springmvc.framework.mapping.impl.BeanNameUrlHandlerMapping

com.yw.springmvc.framework.adapter.HandlerAdapter=com.yw.webmvc.framework.adapter.impl.HttpRequestHandlerAdapter,\
  com.yw.springmvc.framework.adapter.impl.SimpleControllerHandlerAdapter

修改DispatcherServlet：整合Spring框架，并从配置文件中加载默认的处理器映射器、处理器适配器等策略

public class DispatcherServlet extends AbstractServlet {
    /**
     * HandlerMapping的策略集合
     */
    private List<HandlerMapping> handlerMappings = new ArrayList<>();
    /**
     * HandlerAdapter的策略集合
     */
    private List<HandlerAdapter> handlerAdapters = new ArrayList<>();

    private DefaultListableBeanFactory beanFactory;

    private static Properties defaultStrategies;

    static {
        try {
            ClasspathResource resource = new ClasspathResource("DispatcherServlet.properties");
            defaultStrategies = PropertiesLoaderUtils.loadProperties(resource);
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }

    @Override
    public void init(ServletConfig config) throws ServletException {
//        handlerAdapters.add(new HttpRequestHandlerAdapter());
//        handlerAdapters.add(new SimpleControllerHandlerAdapter());
//
//        handlerMappings.add(new BeanNameUrlHandlerMapping());
//        handlerMappings.add(new SimpleUrlHandlerMapping());
        String location = config.getInitParameter("contextConfigLocation");
        // 初始化spring容器
        initContainer(location);
        // 初始化策略集合
        initStrategies();
    }

    private void initContainer(String location) {
        // 加载spring容器需要的BeanDefinition信息
        beanFactory = new DefaultListableBeanFactory();

        ClasspathResource resource = new ClasspathResource(location);
        InputStream inputStream = resource.getResource();

        XmlBeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader(beanFactory);
        beanDefinitionReader.loadBeanDefinitions(inputStream);

        // 注册默认策略BeanDefinition
        registerDefaultStrategies();

        // 将spring容器中管理的所有单例Bean进行初始化(getBean)
        beanFactory.getBeansByType(Object.class);
    }

    private void registerDefaultStrategies() {
        registerDefaultStrategies(HandlerMapping.class);
        registerDefaultStrategies(HandlerAdapter.class);
    }

    private <T> void registerDefaultStrategies(Class<T> strategyInterface) {
        String key = strategyInterface.getName();
        String value = defaultStrategies.getProperty(key);
        if (value == null) {
            return;
        }
        String[] clazzNames = StringUtils.split(value, ",");
        for (String clazzName : clazzNames) {
            try {
                Class<?> clazzType = Class.forName(clazzName);
                String beanName = clazzType.getSimpleName();
                BeanDefinition beanDefinition = new BeanDefinition(clazzName, beanName);
                beanDefinition.setScope("singleton");
                beanFactory.registerBeanDefinition(beanName, beanDefinition);
            } catch (Exception e) {
                System.out.println(e.getMessage());
            }
        }
    }

    private void initStrategies() {
        initHandlerMappings();
        initHandlerAdapters();
    }

    private void initHandlerMappings() {
        handlerMappings = beanFactory.getBeansByType(HandlerMapping.class);
    }

    private void initHandlerAdapters() {
        handlerAdapters = beanFactory.getBeansByType(HandlerAdapter.class);
    }

    // 省略...
}

测试

定义处理器：

public class QueryUserHandler implements HttpRequestHandler {
    @Override
    public void handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/plain;charset=utf-8");
        response.getWriter().write("--- QueryUserHandler V2 ---");
    }
}

public class SaveUserHandler implements SimpleControllerHandler {
    @Override
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/plain;charset=utf-8");
        response.getWriter().write("--- SaveUserHandler V2 ---");
        return null;
    }
}

配置springmvc.xml：

<beans>
  <!-- 配置处理器映射器 -->
  <bean class="com.yw.springmvc.framework.mapping.impl.BeanNameUrlHandlerMapping"/>

  <!-- 配置处理器适配器 -->
  <bean class="com.yw.springmvc.framework.adapter.impl.HttpRequestHandlerAdapter"/>
  <bean class="com.yw.springmvc.framework.adapter.impl.SimpleControllerHandlerAdapter"/>

  <!-- 配置处理器 -->
  <bean name="/queryUser" class="com.yw.springmvc.example.handler.QueryUserHandler" />
  <bean name="/saveUser" class="com.yw.springmvc.example.handler.SaveUserHandler" />
</beans>

配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://java.sun.com/xml/ns/javaee"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
         version="2.5">
  <servlet>
    <servlet-name>dispatcherServlet</servlet-name>
    <servlet-class>com.yw.springmvc.framework.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc.xml</param-value>
    </init-param>
  </servlet>
  <servlet-mapping>
    <servlet-name>dispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

自定义SpringMVC框架V3版本

自定义注解

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
public @interface Controller {
    String value() default "";
}

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD})
public @interface RequestMapping {
    String value() default "";
}

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface ResponseBody {
}

定义RequestMappingHandlerMapping

public class RequestMappingHandlerMapping implements HandlerMapping, InitializingBean, BeanFactoryAware {
    private Map<String, HandlerMethod> urlHandlers = new HashMap<>();

    private DefaultListableBeanFactory beanFactory;

    @Override
    public Object getHandler(HttpServletRequest request) throws Exception {
        String uri = request.getRequestURI();
        return this.urlHandlers.get(uri);
    }

    @Override
    public void setBeanFactory(BeanFactory beanFactory) {
        this.beanFactory = (DefaultListableBeanFactory) beanFactory;
    }

    @Override
    public void afterPropertiesSet() {
        List<BeanDefinition> beanDefinitions = this.beanFactory.getBeanDefinitions();
        for (BeanDefinition bd : beanDefinitions) {
            Class<?> clazzType = bd.getClazzType();
            // 如果类上带有@Controller或者@RequestMapping注解
            if (isHandler(clazzType)) {
                RequestMapping classMapping = clazzType.getAnnotation(RequestMapping.class);
                String classUrl = classMapping.value();

                Method[] methods = clazzType.getDeclaredMethods();
                for (Method method : methods) {
                    if (method.isAnnotationPresent(RequestMapping.class)) {
                        // 建立URL和HandlerMethod对象的映射关系

                        StringBuilder sb = new StringBuilder();
                        if (!classUrl.startsWith("/")) {
                            sb.append("/");
                        }
                        sb.append(classUrl);

                        RequestMapping methodMapping = method.getAnnotation(RequestMapping.class);
                        String methodUrl = methodMapping.value();
                        if (!methodUrl.startsWith("/")) {
                            sb.append("/");
                        }
                        sb.append(methodUrl);

                        // 获取HandlerMethod
                        HandlerMethod hm = new HandlerMethod(beanFactory.getBean(bd.getBeanName()), method);
                        this.urlHandlers.put(sb.toString(), hm);
                    }
                }
            }
        }
    }

    private boolean isHandler(Class<?> clazzType) {
        return (clazzType.isAnnotationPresent(Controller.class)
                || clazzType.isAnnotationPresent(RequestMapping.class));
    }
}

定义RequestMappingHandlerAdapter

public class RequestMappingHandlerAdapter implements HandlerAdapter {
    @Override
    public boolean supports(Object handler) {
        return (handler instanceof HandlerMethod);
    }

    @Override
    public ModelAndView handleRequest(Object handler, HttpServletRequest request, HttpServletResponse response) throws Exception {
        HandlerMethod hm = (HandlerMethod) handler;
        Object controller = hm.getController();
        Method method = hm.getMethod();

        // 处理请求参数
        Object[] args = handleParameters(request, method);

        // 通过反射调用方法
        Object returnValue = method.invoke(controller, args);

        // 处理返回值
        handleReturnValue(returnValue, response);

        return null;
    }

    private Object[] handleParameters(HttpServletRequest request, Method method) {
        List<Object> args = new ArrayList<>();

        // 请求参数KV集合
        Map<String, String[]> parameterMap = request.getParameterMap();

        // 方法参数数组
        Parameter[] parameters = method.getParameters();
        for (Parameter parameter : parameters) {
            // 取出参数名称（需要特殊处理，否则获取到的就是arg0,arg1这样的参数名称）
            String name = parameter.getName();
            Class<?> type = parameter.getType();
            // 方法参数名称一定要和请求的Key保持一致
            String[] strings = parameterMap.get(name);
            Object valueToUse = resolveValue(strings, type);
            args.add(valueToUse);
        }
        return args.toArray();
    }

    private Object resolveValue(String[] strings, Class<?> type) {
        if (type == Integer.class) {
            return Integer.parseInt(strings[0]);
        } else if (type == String.class) {
            return strings[0];
        }
        return null;
    }

    private void handleReturnValue(Object value, HttpServletResponse response) throws Exception {
        if (value instanceof String) {
            response.setContentType("text/plain;charset=utf-8");
            response.getWriter().write(value.toString());
        } else if (value instanceof Map) {
            response.setContentType("application/json;charset=utf-8");
            response.getWriter().write(JsonUtils.object2Json(value));
        }
    }
}

DispatcherServlet.properties新增配置

com.yw.springmvc.framework.mapping.HandlerMapping=com.yw.springmvc.framework.mapping.impl.BeanNameUrlHandlerMapping,\
  com.yw.springmvc.framework.mapping.impl.RequestMappingHandlerMapping

com.yw.springmvc.framework.adapter.HandlerAdapter=com.yw.webmvc.framework.adapter.impl.HttpRequestHandlerAdapter,\
  com.yw.springmvc.framework.adapter.impl.SimpleControllerHandlerAdapter,\
  com.yw.springmvc.framework.adapter.impl.RequestMappingHandlerAdapter

测试

定义控制器：

/**
 * 注意：
 * SpringMvc中的处理器在该类中到底指的是谁？
 * 是Controller类呢？还是其他的？
 * 真正的处理器是Controller中的某个使用RequestMapping注解标记的方法
 * 也就是Controller对象+Method对象==> HandlerMethod对象（真正的处理器）
 */
@Controller
@RequestMapping("user")
public class UserController {

    @RequestMapping("query")
    @ResponseBody
    public Map<String, Object> query(Integer id, String name) {
        Map<String, Object> map = new HashMap<>(2);
        map.put("id", id);
        map.put("name", name);
        return map;
    }

    @RequestMapping("save")
    @ResponseBody
    public String save() {
        return "OK";
    }
}

代码实现github地址

https://github.com/shouwangyw/ssm/tree/main/springmvc-framework-custom

JavaEE 企业级分布式高级架构师（四）SpringMVC学习笔记（2）手写框架篇

SpringMVC学习笔记

手写框架篇

需求分析

自定义SpringMVC框架V1版本

定义处理器

定义处理器映射器

定义处理器适配器

定义前端控制器

配置web.xml

自定义SpringMVC框架V2版本

修改自定义Spring框架整合

修改处理器映射器

修改前端控制器

测试

自定义SpringMVC框架V3版本

自定义注解

定义RequestMappingHandlerMapping

定义RequestMappingHandlerAdapter

DispatcherServlet.properties新增配置

测试

代码实现github地址

继续阅读

SSM框架整合（一）：SSM环境的搭建

用Idea搭建一个简单的SSM框架2

Maven+SSM框架搭建测试（三）

SSM整合之环境搭建

spring_Aop

PDF报表操作05~~SSM整合JasperReport+barcode4j制作动态报表(数据库交互)案例

spring注解的开端（@Component替代bean标签的使用）一、介绍二、简单例子讲解总结：

SpringMVC框架的常用注解1、RequestParam2、RequestBody3、PathVaribale4、RequestHeader5、CookieValue6、ModelAttribute7、SessionAttributes

SpringMVC-4—SpringMVC常用注解一、RequestMapping 注解二、RequestParam注解三、RequestBody注解四、PathVaribale注解五、RequestHeader注解六、CookieValue注解七、SessionAttribute注解

Spring MVC框架搭建

从你的WEB世界路过之--0.初识0) 前言1) WEB基本概念2) 响应数据3. 结语

如何搭建一个SSM框架

spring配置文件拆分细节注意

基于SSM 技术的服装店管理系统

SSM框架（二）------------表现层的SpringMVC

Intellij idea基于Maven 的SSM 框架整合