<!--?xml version="1.0" encoding="UTF-8"?-->
<!-- 定義約束文件 -->（標(biāo)注）
<!-- ELEMENT 表示元素 -->
<!-- ATTLIST 表示屬性 -->
<!-- CDATA 表示字符串類型 -->
<!-- REQUIRED 表示此屬性必須的寫(xiě) -->
<!-- *代表多個(gè) -->
<!-- IMPLIED 表示此屬性可寫(xiě) -->
<!-- redirect 重定向或轉(zhuǎn)發(fā) -->
 
 
  <!--ELEMENT actions (action)-->
  <!--ELEMENT action (result*)-->（*表示可以多個(gè)）
   
  <!--ATTLIST action name CDATA #REQUIRED
           class CDATA #REQUIRED
    -->
  <!--ATTLIST RESULT name CDATA #IMPLIED
     redirect (true|false) "false"
  -->
]>
<framework>
  <!-- 進(jìn)行測(cè)試 -->
<actions>
  <action name="loginAction" class="cn.hq.Action.LoginAction">
  <result name="success">success.jsp</result>
  <result name="login">index.jsp</result>
  </action>
</actions>
</framework>

/*
 * action節(jié)點(diǎn)不止一個(gè)
 * 用來(lái)來(lái)管理ActionMapping類
 */
public class ActionMappingManager {
  //actionMapping類的集合
  private Map<String,ActionMapping> maps=new HashMap<String,ActionMapping>();
   
  public ActionMapping getActionMapping(String name)
  {
     return maps.get(name);
  }
   
  //解析在src項(xiàng)目下的所有配置文件
  //實(shí)例化完畢后進(jìn)行解析
  public ActionMappingManager(String[] file){
    for (String filename : file) {
      Init(filename);
    }
  }
  //init初始化方法
  //解析xml文檔
  public void Init(String path){
     
    try {
       InputStream is=this.getClass().getResourceAsStream("/"+path);
       //解析xml
       Document doc=new SAXReader().read(is);
       //獲取根節(jié)點(diǎn)
       Element root = doc.getRootElement();
       //獲取actions節(jié)點(diǎn)
       Element actions=(Element)root.elementIterator("actions").next();
       //使用for循環(huán)來(lái)遍歷actions節(jié)點(diǎn)下的所有action節(jié)點(diǎn)
       for(Iterator<Element> action=actions.elementIterator("action");action.hasNext();)
       {
         //獲取到<action>節(jié)點(diǎn)
         Element actionnext = action.next();
         //分別獲取到action節(jié)點(diǎn)中的name屬性和class屬性
         String name = actionnext.attributeValue("name");
         String classname = actionnext.attributeValue("class");
         //將以上兩個(gè)屬性保存到ActionMapping類中
         ActionMapping mapp=new ActionMapping();
         mapp.setClassname(classname);
         mapp.setName(name);
         //由于一個(gè)action節(jié)點(diǎn)下有多個(gè)result節(jié)點(diǎn) 遍歷action下所有的result節(jié)點(diǎn)
         for(Iterator<Element> result=actionnext.elementIterator("result");result.hasNext();)
         {
           //獲取到result節(jié)點(diǎn)
           Element resultnext = result.next();
           //提取result節(jié)點(diǎn)的name屬性值和result節(jié)點(diǎn)中的值
           String resultname = resultnext.attributeValue("name");
           String resultvalue=resultnext.getText();
           //將其分別存入到actionMapping中的雙列集合中去，方便調(diào)用actionMapping類(actionMapping類中就有數(shù)據(jù)了!)
           mapp.addResult(resultname, resultvalue);
           System.out.println(mapp.getName());
         }
         //得到所有action節(jié)點(diǎn)的集合
         maps.put(mapp.getName(), mapp);
       }
        
    } catch (Exception e) {
      // TODO: handle exception
    }
   }
  }

public class ActionManager {
 
  public static Action getActionClass(String classname)
  {
    Class clazz=null;
    Action action=null;
    //獲取當(dāng)前線程的類加載器
    try {
      //如果線程中的有那么一個(gè)類，直接根據(jù)類名獲取該類的類型
      clazz=Thread.currentThread().getContextClassLoader().loadClass(classname);
    } catch (ClassNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    if(clazz==null)
    {
      try {
        //如果該線程中沒(méi)有，那么使用class.forname方法獲取
        clazz=Class.forName(classname);
      } catch (ClassNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
    if(action==null)
    {
      try {
        //將獲取到的類型轉(zhuǎn)換為action，調(diào)用無(wú)參構(gòu)造函數(shù)，某種程度上相當(dāng)于new，不過(guò)new需要指定類型
        action=(Action)clazz.newInstance();
      } catch (InstantiationException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      } catch (IllegalAccessException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
    return action;
  }
}　

public class MyServlet extends HttpServlet {
 
  /**
   *你很菜
   */
  public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
 
    doPost(request, response);
  }<br>
  /**
   *繼續(xù)努力
   */
  ActionMappingManager man=null;
  public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
     
    //獲取ActionMapping對(duì)象
    ActionMapping actionMapping = man.getActionMapping(getPath(request));
    //獲取action接口反射機(jī)制
    Action action = ActionManager.getActionManager(actionMapping.getClassname());
     
    try {
      String message=action.execute(request, response);
      String results = actionMapping.getResults(message);
       
      response.sendRedirect(results);
    } catch (Exception e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }
   
  /*
   * 獲取請(qǐng)求的路徑名
   */
  public String getPath(HttpServletRequest request){
    //項(xiàng)目+請(qǐng)求地址
    String requestURI = request.getRequestURI();
    //項(xiàng)目名稱
    String contextPath = request.getContextPath();
    //具體請(qǐng)求
    String path = requestURI.substring(contextPath.length());
    String filename = path.substring(1,path.lastIndexOf("."));
     
    return filename;
  }
  /*
   *重寫(xiě)init,程序運(yùn)行加載所有類
   *
   */
  @Override
  public void init(ServletConfig config) throws ServletException {
 
    //config對(duì)象是javax.servlet.ServletConfig的對(duì)象，功能是獲得初始化配置信息
    //config.getInitParameter是取得指定名稱的初始化參數(shù)內(nèi)容
    String filename = config.getInitParameter("config");
    String [] filenames=null;
    if(filename==null){
      //如果為空 ,
      filenames=new String[]{"Framework.xml"};
    }else{
      //若果有其他的配置參數(shù)信息，那么以，分隔存入數(shù)組中
      filenames=filename.split(",");
    }
    //使用init方法進(jìn)行初始化
    man=new ActionMappingManager(filenames);
  }
}

public class LoginAction implements Action{
 
  @Override
  public String execute(HttpServletRequest request,
      HttpServletResponse response) throws Exception {
     
    String name = request.getParameter("name");
    String pwd = request.getParameter("pwd");
    if(name.equals("1")&&pwd.equals("1")){
      return SUCCESS;
    }else{
      return LOGIN;
    } 
  }
}