查看“SpringMVC：注解开发”的源代码

[[category:SpringMVC]]

== @RequestMapping 使用==
通过RequestMapping注解可以定义不同的处理器映射规则。

=== URL路径映射 ===
<syntaxhighlight lang="java" inline>@RequestMapping(value="/item")</syntaxhighlight>或<syntaxhighlight lang="java" inline>@RequestMapping("/item")</syntaxhighlight>
value的值是数组，可以将多个url映射到同一个方法，如：
<syntaxhighlight lang="java">
@RestController
@RequestMapping("/home ")
public class IndexController {

    @RequestMapping(value = {
        " ",
        "/page ",
        "page* ",
        "view/*,**/msg "
    })
    String indexMultipleMapping() {
        return "Hello from index multiple mapping. ";
    }
}
</syntaxhighlight>
如下的这些 URL 都会由 indexMultipleMapping() 来处理：
* localhost:8080/home
* localhost:8080/home/
* localhost:8080/home/page
* localhost:8080/home/pageabc
* localhost:8080/home/view/
* localhost:8080/home/view/view

=== 窄化请求映射 ===
在class上添加@RequestMapping(url)指定通用请求前缀， 限制此类下的所有方法请求url必须以请求前缀开头，通过此方法对url进行分类管理。<br/>
<syntaxhighlight lang="java">
@Controller
@RequestMapping("/items")
public class ItemsController {

	@Autowired
	private ItemsService itemsService;

	// 商品查询
	@RequestMapping("/queryItems")
	public ModelAndView queryItems(HttpServletRequest request) throws Exception {

		List<ItemsCustom> itemsList = itemsService.findItemsList(null);
		
		ModelAndView modelAndView = new ModelAndView();
		modelAndView.addObject("itemsList", itemsList);
		modelAndView.setViewName("items/itemsList");

		return modelAndView;
	}
...
}
</syntaxhighlight>
商品列表请求路径为：“/items/queryItems.action”。

=== 限定请求方法 ===
出于安全性考虑，对http的链接进行方法限制。<br/>
* HTTP 请求的方法：<syntaxhighlight lang="java" inline>RequestMethod.GET</syntaxhighlight>、<syntaxhighlight lang="java" inline>RequestMethod.POST</syntaxhighlight>、<syntaxhighlight lang="java" inline>RequestMethod.DELETE</syntaxhighlight>、<syntaxhighlight lang="java" inline>RequestMethod.PUT</syntaxhighlight>、<syntaxhighlight lang="java" inline>RequestMethod.PATCH</syntaxhighlight>

<syntaxhighlight lang="java">
//商品信息修改页面显示
@RequestMapping(value="/editItems",method={RequestMethod.POST,RequestMethod.GET})
public ModelAndView editItems()throws Exception {
	
	ItemsCustom itemsCustom = itemsService.findItemsById(1);
	
	ModelAndView modelAndView = new ModelAndView();
	modelAndView.addObject("itemsCustom", itemsCustom);
	modelAndView.setViewName("items/editItems");
	
	return modelAndView;
}
</syntaxhighlight>
如果限制请求为post方法（method={RequestMethod.GET}），进行get请求，报错：
[[File:RequestMapping请求限定.png|400px]]

=== 带有@RequestParam的RequestMapping ===
@RequestParam 的使用：
# 通过在@RequestParam里边指定request传入参数名称和形参进行绑定；
#: <syntaxhighlight lang="java" inline>@RequestParam(value="id") Integer items_id</syntaxhighlight>
# 通过required属性指定参数是否必须要传入；
#: <syntaxhighlight lang="java" inline>@RequestParam(value="id",required=true) Integer items_id</syntaxhighlight>
# 通过defaultValue可以设置默认值，如果形参没有传入，将默认值和形参绑定；
#: <syntaxhighlight lang="java" inline>@RequestParam(value="id",required=true,defaultValue="10001") Integer items_id</syntaxhighlight>
<syntaxhighlight lang="java">
//商品信息修改页面显示
@RequestMapping(value="/editItems",method={RequestMethod.POST,RequestMethod.GET})
public String editItems(Model model,@RequestParam(value="id",required=true) Integer items_id)throws Exception {
	
	ItemsCustom itemsCustom = itemsService.findItemsById(items_id);
	
	//通过形参中的model将model数据传到页面
	//相当于modelAndView.addObject方法
	model.addAttribute("itemsCustom", itemsCustom);
	
	return "items/editItems";
}
</syntaxhighlight>

== Handler方法返回值 ==
=== ModelAndView ===
=== void ===
=== 字符串 ===
==== 逻辑视图名 ====
==== Redirect重定向 ====
==== forward转发 ====

== 参数绑定 ==
=== 默认支持的参数类型 ===
=== 简单类型 ===
=== pojo ===
=== 集合 ===
=== 自定义参数绑定 ===

== 示例代码 ==
=== 需求 ===
=== dao ===
=== service ===
=== controller ===
=== 页面 ===