<dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>servlet-api</artifactId>
      <version>2.5</version>
      <scope>provided</scope>
 </dependency>

     <servlet>
        <servlet-name>appServlet</servlet-name>
        <servlet-class>com.wangcw.cwframework.sevlet.CwDispatcherServlet</servlet-class>
        <init-param>
          <param-name>contextConfigLocation</param-name>
          <param-value>application.properties</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
      </servlet>
      <servlet-mapping>
        <servlet-name>appServlet</servlet-name>
        <url-pattern>/*</url-pattern>
     </servlet-mapping>

 scanPackage=com.wangcw

/*
* 創(chuàng)建一個(gè)類似@Controller作用的注解類
*/
 
import java.lang.annotation.*;
 
@Target({ElementType.TYPE})         
@Retention(RetentionPolicy.RUNTIME)  
@Documented
public @interface CwController {
 
    String value() default "";
}

/*
* 創(chuàng)建一個(gè)類似@Autowried作用的注解類
*/
 
import java.lang.annotation.*;
 
@Target({ElementType.FIELD})        
@Retention(RetentionPolicy.RUNTIME)  
@Documented
public @interface CwAutowried {
 
    String value() default "";
}

/*
* 創(chuàng)建一個(gè)類似@RequestMapping作用的注解類
*/
 
import java.lang.annotation.*;
 
@Target({ElementType.TYPE, ElementType.METHOD})          
@Retention(RetentionPolicy.RUNTIME) 
@Documented
public @interface CwRequestMapping {
 
    String value() default "";
}

/*
* 創(chuàng)建一個(gè)類似@RequsetParam作用的注解類
*/
 
import java.lang.annotation.*;
 
@Target({ElementType.PARAMETER})        
@Retention(RetentionPolicy.RUNTIME)  
@Documented
public @interface CwRequestParam {
 
    String value() default "";
}

/*
* 創(chuàng)建一個(gè)類似@Service作用的注解類
*/
 
import java.lang.annotation.*;
 
@Target({ElementType.TYPE})         
@Retention(RetentionPolicy.RUNTIME) 
@Documented
public @interface CwService {
 
    String value() default "";
}

@CwController  
@CwRequestMapping("/demo")
public class Controller {  
  
    @CwAutowried
    private Service service;  
  
   @CwRequestMapping("/query")
    public void query(HttpServletRequest req, HttpServletResponse resp,@CwRequestParam("name") String name) throws IOException {  
            resp.getWriter().write(service.query(name));  
    }  
  
    @CwRequestMapping("/add") 
    public void add(HttpServletRequest req, HttpServletResponse resp, @CwRequestParam("a") Integer a, @CwRequestParam("b") Integer b) throws IOException {  
        resp.getWriter().write("a+b="+(a+b));  
    }  
}  

public interface Service {
 
         String query(String name);
 
}

@CwService
public class ServiceImpl implements Service{  
  
    @Override  
    public String query(String name) {  
  
        return "I am "+name;  
    }  
}  

 @Override
    public void init(ServletConfig config)  {
 
        /* 1.加載配置文件*/
        doLoadConfig(config.getInitParameter("contextConfigLocation"));
  
        /* 2.掃描scanPackage配置的路徑下所有相關(guān)的類*/
        doScanner(contextConfig.getProperty("scanPackage"));
  
        /* 3.初始化所有相關(guān)聯(lián)的實(shí)例，放入IOC容器中*/
        doInstance();
  
        /*4.實(shí)現(xiàn)自動(dòng)依賴注入 DI*/
        doAutowired();
  
        /*5.初始化HandlerMapping  */
        initHandlerMapping();
 
    }

private Properties contextConfig = new Properties();

String  scanFileDir = contextConfig.getProperty("scanPackage");
 /* 用于存放掃描到的類 */
    private List<String> classNames = new ArrayList<String>();
  /*掃描獲取到對(duì)應(yīng)的class名，便于后面反射使用*/
                String  className = scanPackage + "." + file.getName().replace(".class", "");
                classNames.add(className);

 /* 創(chuàng)建一個(gè)IOC容器 */
    private Map<String, Object> IOC = new HashMap<String, Object>();
 for (String classNme : classNames){
                if( 對(duì)加了 @CwController 注解的類進(jìn)行初始化){
                       /* 對(duì)于初始化的類還需要放入IOC容器，
                          對(duì)于存入IOC的實(shí)例,key值是有一定規(guī)則的,默認(rèn)類名首字母小寫；*/    
   /* toLowerFirstCase是自定義的一個(gè)工具方法，用于將傳入的字符串首字母小寫 */
                    String beanName = toLowerFirstCase(clazz.getSimpleName());
                    IOC.put(beanName, clazz.newInstance());
                } else if (對(duì)加了 @CwService 注解的類進(jìn)行初始化){
                    /* 對(duì)于存入IOC的實(shí)例,key值是有一定規(guī)則的,而Service層的規(guī)則相對(duì)上面更復(fù)雜一些，因?yàn)樽⒔饪梢杂凶远x實(shí)例名，并且可能是接口實(shí)現(xiàn)類 */
      IOC.put(beanName, instance);
                    
                } else {
                    //對(duì)于掃描到的沒有注解的類，忽略初始化行為
                    continue;
                }
            }

  /*遍歷IOC中的所有實(shí)例*/
        for(Map.Entry<String, Object> entry : IOC.entrySet()){
           /* 使用getDeclaredFields暴力反射 */
           Field [] fields = entry.getValue().getClass().getDeclaredFields();
           for (Field field : fields){
               /*1.判斷屬性是否有加注解@CwAutowried.對(duì)于有注解的屬性才需要賦值*/
    ....
    
               /*屬性授權(quán)*/
               field.setAccessible(true);
      field.set(entry.getValue(), IOC.get(beanName));
           }
        }

 /* 創(chuàng)建HandlerMapping存放url,method的匹配關(guān)系 
  其中類Handler是我自己定義的一個(gè)利用正則去匹配url和method，
  只要用戶傳入url，Handler就可以響應(yīng)出其對(duì)應(yīng)的method*/
  private List<Handler> handlerMapping = new ArrayList<Handler>();
 
  /* 遍歷IOC容器 */
  for (Map.Entry<String, Object> entry : IOC.entrySet()){
      Class<?> clazz = entry.getValue().getClass();
      /* 只對(duì)帶有CwController注解的類進(jìn)行處理 */
     
     定義一個(gè)url，由帶有CwController的實(shí)例類上的@CwRequestMapping注解的值和Method上@CwRequestMapping注解的值組成
     
        /* (1).判斷類上是否有CwRequestMapping注解 ，進(jìn)行拼接 url*/
      
 
        /* (2).遍歷實(shí)例下每個(gè)Method,并且需要判斷該方法是否有【 @CwRequestMapping 】注解,拼接url*/
   
     
 
       /* 最后將匹配關(guān)系以正則的形式，放到HandlerMapping集合中 */
       String regex = (url);
       Pattern pattern = Pattern.compile(regex);
       handlerMapping.add(new Handler(pattern,method));
      }

/* 利用反射執(zhí)行其所匹配的方法 */
        handler.method.invoke(handler.controller, paramValues);