一、前言
之前我们通过springMVC前三章讲解了，springMVC的配置以及与mybatis整合的配置运用。这一章是具体的一些操作，可以直接看看项目，下载下来就ok；
二、Controller的返回结果
我们之前都是用modelAndView
1、现在我们看看所有Controller返回方式：void、String、modelAndView
2、
重定向redirect：request无法共享，url变化 用例："redirect:url"
页面转发forword：request共享，url不变化 用例："forward:url"
package com.ycy.controller;
import com.ycy.dto.ItemsCustom;
import com.ycy.service.ItemsService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import java.util.List;
/**
* Created by Administrator on 2015/9/17 0017.
*/
@Controller
@RequestMapping("/items")
public class ItemController {
//注入service
@Autowired
private ItemsService itemsService;
/**
* 商品展示
*
* @param httpServletRequest
* @param httpServletResponse
* @return
* @throws Exception
*/
@RequestMapping("/queryItems")
public ModelAndView queryItems(javax.servlet.http.HttpServletRequest httpServletRequest,
javax.servlet.http.HttpServletResponse httpServletResponse) throws Exception {
//如果是转发：httpServletRequest的数据是可以共享的
ItemsCustom itemsCustom = new ItemsCustom();
itemsCustom.setId(1);
//商品列表
List<ItemsCustom> itemsList = itemsService.findtemsList(null);
//创建modelAndView准备填充数据、设置视图
ModelAndView modelAndView = new ModelAndView();
//填充数据
modelAndView.addObject("itemsList", itemsList);
//视图
modelAndView.setViewName("order/itemsList");
return modelAndView;
}
/**
* 修改商品信息1.1
* @return
* @throws Exception
*/
@RequestMapping("/editItems1")
public ModelAndView editItems() throws Exception {
ModelAndView modelAndView = new ModelAndView();
ItemsCustom itemsCustom = itemsService.getItemsById(1, null);
modelAndView.addObject("item",itemsCustom);
modelAndView.setViewName("order/editItem");
return modelAndView;
}
/**
* 修改商品信息1.2
* @return
* @throws Exception
*/
@RequestMapping("/editItems2")
public String editItems(Model model) throws Exception {
ModelAndView modelAndView = new ModelAndView();
ItemsCustom itemsCustom = itemsService.getItemsById(1, null);
model.addAttribute("item", itemsCustom);
return "order/editItem";
}
/**
* 修改商品信息1.3
* @return
* @throws Exception
*/
@RequestMapping("/editItems")
public void editItems(javax.servlet.http.HttpServletRequest httpServletRequest,
javax.servlet.http.HttpServletResponse httpServletResponse) throws Exception {
ModelAndView modelAndView = new ModelAndView();
ItemsCustom itemsCustom = itemsService.getItemsById(1, null);
httpServletRequest.setAttribute("item", itemsCustom);
httpServletRequest.getRequestDispatcher("/pages/jsp/order/editItem.jsp").forward(httpServletRequest,httpServletResponse);
/**
* 使用此方法，容易输出json、xml格式的数据：
通过response指定响应结果，例如响应json数据如下：
response.setCharacterEncoding("utf-8");
response.setContentType("application/json;charset=utf-8");
response.getWriter().write("json串");
*/
}
/**
* 修改商品属性
* @return
*/
@RequestMapping("/editItemSubmit")
public String editItemSubmit(){
//重定向 request数据无法共享，url地址栏会发生变化的 页面地址：editItemSubmit
return "redirect:queryItems";
//转发 request数据可以共享，url地址栏不会变化 页面地址：queryItems
//return "forward:queryItems";
}
}
三、Controller的参数
来自摘抄：早期springmvc是使用PropertyEditor属性编辑器进行参数绑定(仅支持由字符串传为其它类型)
后期springmvc是使用converter转换器进行参数绑定（支持任意类型转换）
参数类型：1、HttpServletRequest：请求信息
2、HttpServletResponse：处理响应
3、HttpSession：得到session中值
4、Model：通过Model向页面传递数据
5、@RequestParam：对应形参一样自动匹配，否则指定匹配。可以设置默认值，可以设定是否必须传递。
6、简单类型与po类型：int 、double、string、 boolean、 实体UserInfo
示例如下：
@RequestMapping("/testRequestParam")
public void testRequestParam(@RequestParam(value="queryName", required=true,defaultValue = "") String name ){
// 上面的对传入参数指定为queryName，如果前端不传queryName参数名，会报错
// required=false表示不传的话，会给参数赋值为null，required=true就是必须要有
}
@RequestMapping("/testModel")
public String testModel(Model model )throws Exception {
ModelAndView modelAndView = new ModelAndView();
ItemsCustom itemsCustom = itemsService.getItemsById(1, null);
model.addAttribute("item", itemsCustom);
return "order/editItem";
}
@RequestMapping("/testHttpSession")
public void testHttpSession(HttpSession httpSession )throws Exception {
httpSession.getAttribute("username");
}
@RequestMapping("/testHttpSession")
public void testHttprequest(javax.servlet.http.HttpServletRequest httpServletRequest,
javax.servlet.http.HttpServletResponse httpServletResponse)throws Exception {
httpServletRequest.setAttribute("obj", null);
httpServletRequest.getRequestDispatcher("/pages/jsp/XXX/XXXX.jsp").forward(httpServletRequest,httpServletResponse);
}
2.1自定义参数（了解）
例如：springMvc没定义日期类型绑定。需要自定义！！！
2.1.1 Controller内自定义属性编辑器
在每一个Controller类里面加一个这样的方法就可以转换日期格式了哦，或者用在父类写入这个方法，继承一个父类就OK。
//自定义编辑器
/**
* 注册属性编辑器(字符串转换为日期)
*/
@InitBinder
public void initBinder(WebDataBinder binder) throws Exception {
binder.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd HH-mm-ss"),true));
//System.out.println("init binder =======================");
binder.registerCustomEditor(BigDecimal.class, new CustomNumberEditor(BigDecimal.class, false));
binder.registerCustomEditor(Integer.class, null,new CustomNumberEditor(Integer.class, null, true));
binder.registerCustomEditor(Long.class, null, new CustomNumberEditor(Long.class, null, true));
binder.registerCustomEditor(Float.class, new CustomNumberEditor(Float.class, true));
binder.registerCustomEditor(Double.class, new CustomNumberEditor(Double.class, true));
binder.registerCustomEditor(BigInteger.class, new CustomNumberEditor(BigInteger.class, true));
}
2.1.2属性 配置编译器xml
1、编写属性编译器java类：
propertyeditor
package com.ycy.propertyeditor;
import org.springframework.beans.PropertyEditorRegistrar;
import org.springframework.beans.PropertyEditorRegistry;
import org.springframework.beans.propertyeditors.CustomDateEditor;
import org.springframework.beans.propertyeditors.CustomNumberEditor;
import java.beans.PropertyEditor;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.text.SimpleDateFormat;
import java.util.Date;
/**自定义属性编辑器
* Created by Administrator on 2015/9/24 0024.
*/
public class CustomPropertyEditor implements PropertyEditorRegistrar {
@Override
public void registerCustomEditors(PropertyEditorRegistry binder) {
binder.registerCustomEditor(Date.class, new CustomDateEditor(new SimpleDateFormat("yyyy-MM-dd HH-mm-ss"),true));
//System.out.println("init binder =======================");
binder.registerCustomEditor(BigDecimal.class, new CustomNumberEditor(BigDecimal.class, false));
binder.registerCustomEditor(Integer.class, null,new CustomNumberEditor(Integer.class, null, true));
binder.registerCustomEditor(Long.class, null, new CustomNumberEditor(Long.class, null, true));
binder.registerCustomEditor(Float.class, new CustomNumberEditor(Float.class, true));
binder.registerCustomEditor(Double.class, new CustomNumberEditor(Double.class, true));
binder.registerCustomEditor(BigInteger.class, new CustomNumberEditor(BigInteger.class, true));
}
}
2、在handlerAdapter适配器中加入我们的属性适配器
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-4.0.xsd ">
<!--1、=========================dispatcher已经在web.xml里面配置==================================-->
<!-- 使用spring组件扫描 -->
<context:component-scan base-package="com.ycy.controller"/>
<!-- 2、3 通过annotation-driven可以替代下边的处理器映射器和适配器 -->
<!-- <mvc:annotation-driven conversion-service="conversionService"></mvc:annotation-driven>-->
<!--2、=======================使用注解RequestMappingInfoHandlerMapping映射器======================-->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/>
<!--3、=============================处理器适配器HandlerAdapter====================================-->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
<!--注解适配器:加入我们的属性解析器 -->
<property name="webBindingInitializer" ref="customBinder"></property>
</bean>
<!--4、============================视图解析器ViewResolver======================================-->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
<property name="prefix" value="/pages/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>
<!--5、视图view与hanlder需要自己实现-->
<!-- ================================自定义webBinder:属性编辑器===================================-->
<bean id="customBinder"
class="org.springframework.web.bind.support.ConfigurableWebBindingInitializer">
<property name="propertyEditorRegistrars">
<list>
<!-- 注册属性编辑器 -->
<bean id="customPropertyEditor" class="com.ycy.propertyeditor.CustomPropertyEditor" />
</list>
</property>
</bean>
</beans>
2.2参数转换器（必须掌握）
2.2.1 配置方式 1 针对不使用 <mvc:annotation-driven>
1首先编写java转换器
package com.ycy.controller.converter;
import org.springframework.core.convert.converter.Converter;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
* Created by Administrator on 2015/9/24 0024.
*/
public class CustomDateConverter implements Converter<String, Date> {
@Override
public Date convert(String source) {
try {
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
return simpleDateFormat.parse(source);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}</span>
2其次根据写的Jva类配置springMcv.xml
<bean id="customBinder"
class="org.springframework.web.bind.support.ConfigurableWebBindingInitializer">
<property name="conversionService" ref="conversionService" />
</bean>
<!-- conversionService -->
<bean id="conversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
<!-- 转换器 -->
<property name="converters">
<list>
<bean class="com.ycy.controller.converter.CustomDateConverter"/>
</list>
</property>
</bean>
3加入适配器
<!--3、=============================处理器适配器HandlerAdapter====================================-->
<bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
<!--注解适配器:加入我们的属性解析器 -->
<property name="webBindingInitializer" ref="customBinder"></property>
</bean>
2.2.2 配置方式2针对使用<mvc:annotation-driven>的配置
1首先编写java转换器同上<!-- conversionService -->
<bean id="conversionService"
class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
<!-- 转换器 -->
<property name="converters">
<list>
<bean class="com.ycy.controller.converter.CustomDateConverter"/>
</list>
</property>
</bean>
3加入适配器
<mvc:annotation-driven conversion-service="conversionService"> </mvc:annotation-driven>
四、Controller的总结
这一讲主要讲解Controlleer的返回结果，传入参数。加上mybatis的缓存等等（看mybatis篇先），基本上能够应对你的项目开发的全部。但是发现没有，你熟悉的Json转换器怎么不出现在参数转换与结果返回里面？？下一章开始进行中级讲解，就会有一些好用的图片上传、拦截器之类的。
