springmvc部分要点笔记

要点笔记"/>

springmvc部分要点笔记

RequestMapping

一、参数

value

method(get post delete put)

(异常 404 资源不存在 405 参数有问题 500程序有异常)、

params 参数是强制限定请求参数的名称或者值，或者名称和值

二、请求风格

传统url：localhost：8080/hello?id=12&name=tom

restful url : localhost：8080/hello/12/tom

@RequestMapping("/test2/{id}/{name}")
public String test2(@PathVariable("id") Integer id ,@PathVariable("name") String name){System.out.println("name : " + name + "id : " + id);return SUCCESS;
}

三、映射cookie

@RequestMapping("/getcookie")
public String test3(@CookieValue("JSESSIONID") String sessionId){System.out.println("JSESSIONID" + sessionId);return SUCCESS;
}

四、获取模型对象数据

直接在方法参数中定义一个pojo变量，支持级联赋值

@RequestMapping("/adduser")
public String test4(User user){System.out.println(user);return SUCCESS;
}

<form action="/hello/adduser" method="post"><table><tr><td>姓名：</td><td><input type="text" name="name"></td></tr><tr><td>id :</td><td><input type="text" name="id"></td></tr><tr><td>编码 :</td><td><input type="text" name="address.code"></td></tr><tr><td>值 :</td><td><input type="text" name="address.value"></td></tr><tr><td></td><td><input type="submit" value="提交"></td></tr></table>
</form>

支持级联赋值，但必须要求包含的类有无参构造，否则无法创建会出现下面异常

org.springframework.beans.NullValueInNestedPathException: Invalid property 'address' of bean class [com.zw.entity.User]: Could not instantiate property type [com.zw.entity.Address] to auto-grow nested property path; nested exception is java.lang.NoSuchMethodException: com.zw.entity.Address.<init>()

乱码问题解决：

<filter><filter-name>EncodingFilter</filter-name><filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class><init-param><param-name>encoding</param-name><param-value>UTF-8</param-value></init-param>
</filter>
<filter-mapping><filter-name>EncodingFilter</filter-name><url-pattern>/*</url-pattern>
</filter-mapping>

五、重定向

redirect:物理路径

forward：物理路径

否则会无限次重新访问

@RequestMapping("/test2/{id}/{name}")
public String test2(@PathVariable("id") Integer id ,@PathVariable("name") String name){System.out.println("name : " + name + "id : " + id);return "redirect:/index.jsp";
}

@RequestMapping("/test2/{id}/{name}")
public String test2(@PathVariable("id") Integer id ,@PathVariable("name") String name){System.out.println("name : " + name + "id : " + id);return "forward:/index.jsp";
}

数据绑定

基本数据类型

这里的请求id不能为空

http://localhost:8080/hello/baseType?id=12

@RequestMapping("/baseType")
@ResponseBody
public String test5(int id){return "id:"+id;
}

http://localhost:8080/hello/baseType

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http://localhost:8080/hello/baseType?id=a

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包装类

@RequestMapping("/packageType")
@ResponseBody
public String test6(Integer id){return "id:"+id;
}

请求参数可以为空显示为null

@RequestMapping("/paramrequire")
@ResponseBody
public String test7(@RequestParam(value = "id",required = true,defaultValue = "0") Integer id){return "id:"+id;
}

设置requestParam注解参数，设置其为必须，默认值为0

数组绑定

把请求参数中的names属性都添加到数组中去

@RequestMapping("/arrayType")
@ResponseBody
public String test8(String[] names){StringBuffer buffer = new StringBuffer();for(String name : names){buffer.append(name+" ");}return buffer.toString();
}

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绑定对象

@Data
public class User {private Integer id ;private String name ;<