标签：告诉 err 帮助 public except form表单 field 上传图片 for
使用 @RequestParam 可以传递查询参数。例如：http://localhost:8092/category/detail?id=1
@RequestMapping("/detail")
public String detail(@RequestParam("id") int id,Model model){
Category category=new Category();
category.setCateId(id);
category.setCateName("测试分类"+id);
model.addAttribute("cate",category);
return "detail.html";
}
使用 @PathVariable可以传递路径参数。例如：http://localhost:8092/category/edit/1
@RequestMapping(value = "/edit/{id}",method = RequestMethod.GET)
public String edit(@PathVariable("id") int id,Model model) {
//todo:get category from db
Category category=new Category();
category.setCateId(id);
category.setCateName("测试分类"+id);
model.addAttribute("cate",category);
return "edit.html";
}
1.首先定义实体类。
public class Category{
public Category(){}
@NotNull
@Min(1)
private int cateId;
@NotNull
private String cateName;
public int getCateId() {
return cateId;
}
public void setCateId(int cateId) {
this.cateId = cateId;
}
public String getCateName() {
return cateName;
}
public void setCateName(String cateName) {
this.cateName = cateName;
}
}
2.表单edit.html
<form method="post" th:object="${cate}" th:action="@{/category/save}" enctype="multipart/form-data">
<table>
<tr>
<td>id:</td>
<td><input type="text" th:field="*{cateId}"></td>
</tr>
<tr>
<td>name:</td>
<td><input type="text" th:field="*{cateName}"></td>
</tr>
<tr>
<td colspan="2">
<input type="submit" value="提交">
</td>
</tr>
</table>
</form>
3.通过给action方法的参数添加@Valid注解，这会告知Spring，需要确保这个对象满足校验限制
@RequestMapping(value = "/save",method = RequestMethod.POST)
public String save( @Valid Category category, Errors errors) throws IOException {...}
错误可以通过Errors对象进行访问，现在这个对象已作为processRegistration()方法的参数。（很重要一点需要注意，Errors参数要紧跟在带有@Valid注解的参数后面，@Valid注解所标注的就是要检验的参数。
1.设置web.xml配置
web.xml配置multipart-config
<servlet>
<servlet-name>springmvc</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
<multipart-config>
<location></location>
<max-file-size>2097152</max-file-size>
<max-request-size>4194304</max-request-size>
</multipart-config>
</servlet>
2.from表单
form要将enctype属性设置为multipart/form-data，这就告诉浏览器以multipart数据的形式提交表单
input标签要把type设置为file，这能够让用户选择要上传的图片文件。accept属性用来将文件类型限制为JPEG、PNG以及GIF图片。根据其name属性，图片数据将会发送到multipart请求中的profilePicture part之中
<form method="post" th:object="${cate}" th:action="@{/category/save}" enctype="multipart/form-data">
<table>
<tr>
<td>id:</td>
<td><input type="text" th:field="*{cateId}"></td>
</tr>
<tr>
<td>name:</td>
<td><input type="text" th:field="*{cateName}"></td>
</tr>
<tr>
<td>file:</td>
<td>
<input type="file" accept="image/jpeg,image/png,image/jpg" name="picture">
</td>
</tr>
<tr>
<td colspan="2">
<input type="submit" value="提交">
</td>
</tr>
</table>
</form>
3.controller:
@RequestPart ：图片对应的参数要添加该注解
spring提供了Multipart MultipartFile对象，它为处理multipart数据提供了内容更为丰富的对象
transferTo() ，它能够帮助我们将上传的文件写入到文件系统中
@RequestMapping(value = "/save",method = RequestMethod.POST)
public String save(@RequestPart("picture") MultipartFile picture, @Valid Category category, Errors errors) throws IOException {
//todo:save file to image server
String filepath=request.getRealPath("/")+"upload/"+picture.getOriginalFilename();
picture.transferTo(new File(filepath));
if(errors.hasErrors()){
return "edit.html";
}
//todo:save category to db
return "redirect:/category/detail?id="+category.getCateId();
}
标签：告诉 err 帮助 public except form表单 field 上传图片 for
原文地址：http://www.cnblogs.com/janes/p/6933723.html
