前言

先说好，本次因为运用的是上次【mvc的增强】的知识，所以不会去过多的去讲解，本次跟多的是案例。
若有不理解的请看【mvc的增强】

中央控制器 DispactherServlet(按照运行顺序来)

public class DispatcherServlet extends HttpServlet{
	
	
//	private Map<String, action> actionMap = new HashMap<>();//用来存储子控制器的位置
	
	private configModel config = null ;
	
	public void init() {
		try {
			
			//使得调用指定位置的xml文件
			String xmlpath  = this.getInitParameter("xmlpath");
			if(xmlpath==null||"".equals(xmlpath)) {
				config = configModelFactory.build();
			}
			else {
				config = configModelFactory.build(xmlpath);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		
	}
	
	
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		doPost(req, resp);
	}
	
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

		
		init();//使得map里有值
		String requestURI = req.getRequestURI(); //获取请求的路径
		System.out.println("截取前："+requestURI);
		
		String url = requestURI.substring(requestURI.lastIndexOf("/"), requestURI.lastIndexOf("."));//截取
		System.out.println("截取后："+url);
		
		
		actionModel actionModel = config.pop(url);
		if(actionModel==null) {
			throw new RuntimeException("你没有配置相关的action");
		}
		
		try {
			action action = (action)Class.forName(actionModel.getType()).newInstance();//实列化xml中type里面的内容地址
			//calAction
			
			if(action instanceof ModelDirven) {
				ModelDirven modeldirven = (ModelDirven)action;
				Object model = modeldirven.getModel();
				
//				Map<String, String[]> parameterMap = req.getParameterMap();
//				for (Entry<String, String[]> entry : parameterMap.entrySet()) {
//					
//					Field[] declaredFields = model.getClass().getDeclaredFields();
//					for (Field field : declaredFields) {
//						if(entry.getKey().equals(field.getName())) {
//							Field declaredField = model.getClass().getDeclaredField(entry.getKey());
//							declaredField.setAccessible(true);
//							declaredField.set(model, entry.getValue());
//						}
//					}
//					
//				}
//				
				BeanUtils.populate(model, req.getParameterMap());//本行代码意思可以看到上面注释
			}
						//calAction
			String code = action.execute(req, resp);//获取返回路径的名字
			forwardModel forwardModel = actionModel.pop(code);
			
			if(forwardModel==null) {
				throw new RuntimeException("你没有配置对应子控制器action的处理方式");
			}
			
			String jsppath = forwardModel.getPath();//获取返回的路径
			
			if(forwardModel.isRedirect()) {//判断是否要重定向
				resp.sendRedirect(req.getContextPath()+jsppath);
			}
			else  {//判断是否要转发
				req.getRequestDispatcher(jsppath).forward(req, resp);
			}
			
			
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} catch (InvocationTargetException e) {
			e.printStackTrace();
		}  catch (SecurityException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		
	}
	
}

子控制接口 action

public interface action {
	
	String execute(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException;

}

子控制器超类 actionSupper

public class actionSupper implements action {


	public final String execute(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		String code = null;
		try {
			Method Method = this.getClass().getDeclaredMethod(req.getParameter("method"), HttpServletRequest.class,HttpServletResponse.class);
			Method.setAccessible(true);
			code = (String) Method.invoke(this, req,resp);//获取在方法的返回值
			
			
		} catch (NoSuchMethodException e) {
			e.printStackTrace();
		} catch (SecurityException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		} catch (InvocationTargetException e) {
			e.printStackTrace();
		}
		
		return code;
	}

}

总方法集合 StudentAction

public class StudentAction extends actionSupper implements ModelDirven<student>{
	private studentDao sd = new studentDao();
	private student stu = new student ();
	
	public String getAll(HttpServletRequest req,HttpServletResponse resp) {
		
		PageBean page = new PageBean();
		page.setRequest(req);
		List<student> list = sd.getAll(stu, page);
		System.out.println("数量"+list.size());
		req.setAttribute("list", list);
		req.setAttribute("PageBean", page);
		
		return "index";
	}
	
	public String deleteStu(HttpServletRequest req,HttpServletResponse resp) {
		
		int n = sd.deleteStu(stu);
		if(n>0) {
			System.out.println("删除成功");
		}
		else {
			System.out.println("删除失败");
		}
		return "Reindex";
	}
	public String loadStu(HttpServletRequest req,HttpServletResponse resp) {
		
		List<student> list = sd.getAll(stu, null);
		System.out.println(list.size());
		req.setAttribute("stu", list.get(0));
		System.out.println(list.get(0));
		return "preupdate";
	}
	
	public String updateStu(HttpServletRequest req,HttpServletResponse resp) {
		
		int n = sd.updateStu(stu);
		if(n>0) {
			System.out.println("修改成功");
		}
		else {
			System.out.println("修改失败");
		}
		
		return "Reindex";
	}
	public String addStu(HttpServletRequest req,HttpServletResponse resp) {
		
		int n = sd.addStu(stu);
		if(n>0) {
			System.out.println("增加成功");
		}
		else {
			System.out.println("增加失败");
		}
		
		return "Reindex";
	}
	

	@Override
	public student getModel() {
		return stu;
	}

}

自动调用参数的 ModelDirven

public interface ModelDirven<T>{
	T getModel();

}

方法 BeanDao

public class BeanDao<T> {
	
	Connection con = null;
	PreparedStatement pst = null;
	ResultSet rs = null;

	
	
	public List<T> executeQuery(String sql ,Class clz ,PageBean page ){
		List<T> lt = new ArrayList<>();
		try {
			con = DBAccess.getConnection(); //连接三部曲
			
			if(page!=null&&page.isPagination()) {//要进行分页的进这里
				
				String countPage = countPage(sql);//获取这个类在数据库的总行数
				pst = con.prepareStatement(countPage);
				rs = pst.executeQuery(); 
				if(rs.next()) {
					page.setTotal(rs.getLong(1)+"");
				}
				
				String getPage = getPage(sql,page);//获取这个页面的页数
				
				pst = con.prepareStatement(getPage);
				rs = pst.executeQuery();
				
			}
			else {
				pst = con.prepareStatement(sql);//连接三部曲
				rs = pst.executeQuery(); //连接三部曲
			}
			while (rs.next()) {
				T t = (T) clz.newInstance();//将传过来的class文件实列化，类型为实现本类的T参数
				Field[] fields = clz.getDeclaredFields();//获取这个类里的所有属性
				for (Field field : fields) { //遍历
					System.out.println(field.getName()+":"+rs.getObject(field.getName()));
					field.setAccessible(true);  //打开权限
						field.set(t, rs.getObject(field.getName()));
				}
				System.out.println(t.toString());
				lt.add(t);//加入到集合内部
			} 
		} catch (IllegalArgumentException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (InstantiationException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		finally {
			DBAccess.close(con, pst, rs);
		}
		return lt;
	}
	
	
	//增 ,删，改
	public int executeUpdate(String sql ,String [] attrs ,T t ){
		int n = 0;
		try {
			
			con = DBAccess.getConnection();  //连接三部曲
			pst = con.prepareStatement(sql); //连接三部曲
			for (int i = 0; i < attrs.length; i++) {
				Field Field = t.getClass().getDeclaredField(attrs[i]);
				Field.setAccessible(true);
				pst.setObject(i+1, Field.get(t));
			}
			n= pst.executeUpdate();
		} catch (IllegalArgumentException e) {
			e.printStackTrace();
		}  catch (SQLException e) {
			e.printStackTrace();
		}catch (NoSuchFieldException e) {
			e.printStackTrace();
		} catch (SecurityException e) {
			e.printStackTrace();
		}catch (IllegalAccessException e) {
			e.printStackTrace();
		}
		finally {
			DBAccess.close(con, pst, rs);
		}
		return n;
	}
	
	
	


private String getPage(String sql, PageBean page) {
	return sql+" limit "+page.getStartIndex()+","+page.getRows();
}


private String countPage(String sql) {
	return "select count(1) from ( "+sql+" ) t";
}
	

}

方法调用 StudentDao

public class studentDao extends BeanDao<student>{
/**
	 * 删除
	 * @param stu
	 * @return
	 */
	public int deleteStu(student stu){
		String sql = "delete from tb_student where sid = ?";
		return super.executeUpdate(sql, new String [] {"sid" }, stu);
	}
	/**
	 * 增加
	 * @param stu
	 * @return
	 */
	public int addStu(student stu){
		String sql = "insert into tb_student(sid,sname,tid,cid,shobby) values(?,?,?,?,?)";
		return super.executeUpdate(sql, new String [] {"sid","sname","tid","cid","shobby" }, stu);
	}
	/**
	 * 修改
	 * @param stu
	 * @return
	 */
	public int updateStu(student stu){
		String sql = "update tb_student set sname=?,tid=?,cid=?,shobby=? where sid = ? ";
		return super.executeUpdate(sql, new String [] {"sname","tid","cid","shobby","sid"}, stu);
	}
	
	
	public List<student> getAll(student stu, PageBean page){
		String sql = " select * from tb_student where 1=1 ";
		
		if(StringUtils.isNotBlank(stu.getSid()+"")&& stu.getSid() !=0) {
			sql += " and sid = "+stu.getSid()+"  ";
		}
		if(StringUtils.isNotBlank(stu.getTid()+"")&& stu.getTid() !=0) {
			sql += " and tid = "+stu.getTid()+"  ";
		}
		if(StringUtils.isNotBlank(stu.getCid()+"")&& stu.getCid() !=0) {
			sql += " and cid = "+stu.getCid()+"  ";
		}
		if(StringUtils.isNotBlank(stu.getShobby())) {
			sql += " and shobby like '%"+stu.getShobby()+"%' ";
		}
		
		return super.executeQuery(sql, student.class, page);
	}

}

xml的配置

<config>
	<action path="/StudentAction" type="com.web.StudentAction">
		<forward name="index" path="/index.jsp" redirect="false" />
		<forward name="Reindex" path="/StudentAction.action?method=getAll" redirect="true" />
		<forward name="preupdate" path="/update.jsp" redirect="false" />
	</action>

</config>

前台调用xml

<filter>
  	<filter-name>encoding</filter-name>
  	<filter-class>com.filer.EncodingFiter</filter-class>
  </filter>
  <filter-mapping>
  	<filter-name>encoding</filter-name>
  	<url-pattern>/*</url-pattern>
  </filter-mapping>
  
  <servlet>
  	<servlet-name>dispatcherServlet</servlet-name>
  	<servlet-class>com.framework.DispatcherServlet</servlet-class>//中央处理器
  </servlet>
  
  <servlet-mapping>
  	<servlet-name>dispatcherServlet</servlet-name>
  	<url-pattern>*.action</url-pattern>
  </servlet-mapping>

调用代码

	href = "StudentAction.action?method=getAll";
	//method就放自己定义好的方法名就行

---

总结

总的来说，代码量还好，理清思路最为关键

Thanks♪(･ω･)ﾉ希望对大家有所帮助