SpringMVC进阶

1.springmvc（注解版本）

注解扫描

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd

       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <!--让spring容器去扫描注释-->
    <context:component-scan base-package="com.juaner.app14"/>

    <!--视图解析器-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

Action类

@Controller
public class HelloAction {
    public HelloAction(){
        System.out.println(this .hashCode() );
    }
    @RequestMapping(value = "/hello.action")
    public String hello(Model model)throws Exception{
        System.out.println("hello");
        model.addAttribute("message","this is the first....");
        return "success";
    }

    @RequestMapping(value = "/bye.action")
    public String bye(Model model)throws Exception{
        System.out.println("bye");
        model.addAttribute("message","bye");
        return "success";
    }
}

2.一个Action中，写多个类似的业务控制方法

@Controller
@RequestMapping(value="/user")
public class UserAction {

    @RequestMapping(value = "/register")
    public String register(Model model)throws Exception{
        model.addAttribute("message","注册成功");
        return "/jsp/success.jsp";
    }
    @RequestMapping(value = "/login")
    public String login(Model model)throws Exception{
        model.addAttribute("message","登录成功");
        return "/jsp/success.jsp";
    }
}

3.在业务控制方法中写入普通变量收集参数，限定某个业务控制方法，只允许GET或POST请求方式访问

@Controller
@RequestMapping(value="/user")
public class UserAction {

    @RequestMapping(method= RequestMethod.POST,value = "/register")
    public String register(Model model,String username,double salary)throws Exception{
        System.out.println(username+salary);
        model.addAttribute("message","注册成功");
        return "/jsp/success.jsp";
    }
    @RequestMapping(value = "/login", method= {RequestMethod.POST,RequestMethod.GET})
    public String login(Model model,String username,double salary)throws Exception{
        System.out.println(username+salary);
        model.addAttribute("message","登录成功");
        return "/jsp/success.jsp";
    }
}

4.在业务控制方法中写入HttpServletRequest，HttpServletResponse，Model等传统web参数

@Controller
@RequestMapping(value="/user")
public class UserAction {

    @RequestMapping(method= RequestMethod.POST,value = "/register" )
    public void  register(HttpServletRequest request, HttpServletResponse response)throws Exception{
        String username = request.getParameter("username");
        String salary = request.getParameter("salary");

        System.out.println(username+salary);
        request.setAttribute("message","转发参数");
//        response.sendRedirect(request.getContextPath()+"/jsp/success.jsp");
        request.getRequestDispatcher("/jsp/success.jsp").forward(request,response);
    }
}

5.在业务控制方法中写入模型变量收集参数，且使用@InitBind来解决字符串转日期类型

　　jsp中的元素name属性不用加user.前缀

@Controller
@RequestMapping(value="/user")
public class UserAction {

    @InitBinder
    protected void initBinder(HttpServletRequest request, ServletRequestDataBinder binder) throws Exception {
        //向springmvc中注册一个自定义的类型转换器
        //参数一：将string转成什么类型的字节码
        //参数二：自定义转换规则
        binder.registerCustomEditor(Date.class,
                new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd"),true));
    }
    @RequestMapping(method= RequestMethod.POST,value = "/register" )
    public String   register(User user, Model model)throws Exception{
        System.out.println("用户注册");
        model.addAttribute("user",user);
        System.out.println(new Timestamp(user.getHiredate().getTime()));

        return "/jsp/success.jsp";
    }
}

　　在业务控制方法中写入User，Admin多个模型收集参数，需要更大的模型包装User，Admin

6.在业务控制方法中收集数组参数

@Controller
@RequestMapping(value = "/emp")
public class EmpAction {
    @RequestMapping(value = "/deleteAll",method = RequestMethod.POST)
    public String deleteAll(Model model,int[] id)throws Exception{
        for(int i:id)
        {
            System.out.println(i);
        }
        model.addAttribute("message","批量删除员工成功");
        return "/jsp/success.jsp";
    }
}

jsp

<form action="${pageContext.request.contextPath}/emp/deleteAll.action" method="post">
    <table>
        <tr><th>
            编号
        </th><th>
            姓名
        </th></tr>

        <tr>
            <td>
                <input type="checkbox" name="id" value="1123">
            </td>
            <td>哈哈</td>
        </tr>
        <tr>
            <td>
                <input type="checkbox" name="id" value="2123">
            </td>
            <td>嘻嘻</td>
        </tr>
        <tr>
            <td>
                <input type="checkbox" name="id" value="3">
            </td>
            <td>呵呵</td>
        </tr>
        <tr>
            <td colspan="2">
                <input type="submit" value="提交">
            </td>
        </tr>
    </table>
</form>

7.在业务控制方法中收集List<JavaBean>参数

bean

public class Bean {
    private List<Emp> empList = new ArrayList<Emp>();
    public  Bean(){}

    public List<Emp> getEmpList() {
        return empList;
    }

    public void setEmpList(List<Emp> empList) {
        this.empList = empList;
    }
}

action

@Controller
@RequestMapping(value = "/emp")
public class EmpAction {
    @RequestMapping(value = "/addAll",method = RequestMethod.POST)
    public String addAll(Model model,Bean bean)throws Exception{
        for(Emp emp:bean.getEmpList())
        {
            System.out.println(emp);
        }
        model.addAttribute("message","批量添加员工成功");
        return "/jsp/success.jsp";
    }
}

jsp

<form action="${pageContext.request.contextPath}/emp/addAll.action" method="post">
    <table>
        <tr>
            <td><input name="empList[0].username" type="text" value="哈哈"></td>
            <td><input name="empList[0].salary" type="text" value="6000"></td>
        </tr>
        <tr>
            <td><input name="empList[1].username" type="text" value="呵呵"></td>
            <td><input name="empList[1].salary" type="text" value="7000"></td>
        </tr>
        <tr>
            <td><input name="empList[2].username" type="text" value="嘻嘻"></td>
            <td><input name="empList[2].salary" type="text" value="8000"></td>
        </tr>
        <tr>
            <td colspan="2" align="center"><input  type="submit" value="注册"></td>
        </tr>
    </table>
</form>

8.结果的转发和重定向

@Controller
@RequestMapping(value="/emp")
public class EmpAction {

    @RequestMapping(value="/find")
    public String findEmpById(int id,Model model) throws Exception{
        System.out.println("查询"+id+"号员工信息");

        //转发到EmpAction的另一个方法中去，即再次发送请求
        return "forward:/emp/update.action";

        //重定向到EmpAction的另一个方法中去，即再次发送请求
        //return "redirect:/emp/update.action?id=" + id;

    }

    @RequestMapping(value="/update")
    public String updateEmpById(int id,Model model) throws Exception{
        System.out.println("更新" + id +"号员工信息");
        model.addAttribute("message","更新员工信息成功");
        return "/jsp/ok.jsp";
    }

}

9.异步发送表单数据到JavaBean，并响应JSON文本返回

1.导入包jackson-core-asl-1.9.11、jackson-mapper-asl-1.9.11

2.配置json转换器

    <!--json转换器-->
    <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
        <property name="messageConverters">
            <list>
                <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter"/>
            </list>
        </property>
    </bean>

3.方法名中加注解

    /**
     * @ResponseBody Emp 表示让springmvc将Emp对象转成json文本
     */
    @RequestMapping(value="/bean2json")
    public @ResponseBody Emp bean2json() throws Exception{
        //创建Emp对象
        Emp emp = new Emp();
        emp.setId(1);
        emp.setUsername("哈哈");
        emp.setSalary(7000D);
        emp.setHiredate(new Date());
        return emp;
    }

    @RequestMapping(value="/listbean2json")
    public @ResponseBody List<Emp> listbean2json() throws Exception{
        //创建List对象
        List<Emp> empList = new ArrayList<Emp>();
        //向List对象中添加三个Emp对象
        empList.add(new Emp(1,"哈哈",7000D,new Date()));
        empList.add(new Emp(2,"呵呵",8000D,new Date()));
        empList.add(new Emp(3,"嘻嘻",9000D,new Date()));
        //返回需要转JSON文本的对象
        return empList;
    }

    @RequestMapping(value="/map2json")
    public @ResponseBody Map<String,Object> map2json() throws Exception{
        //创建List对象
        List<Emp> empList = new ArrayList<Emp>();
        //向List对象中添加三个Emp对象
        empList.add(new Emp(1,"哈哈",7000D,new Date()));
        empList.add(new Emp(2,"呵呵",8000D,new Date()));
        empList.add(new Emp(3,"嘻嘻",9000D,new Date()));
        //创建Map对象
        Map<String,Object> map = new LinkedHashMap<String,Object>();
        //向Map对象中绑定二个变量
        map.put("total",empList.size());
        map.put("rows",empList);
        //返回需要转JSON文本的对象
        return map;
    }