1 @ControllerAdvice 3 种用法
处理全局异常预设全局数据请求参数预处理
2 全局异常处理
依赖
<dependency>
<groupId>org.springframework.boot
</groupId>
<artifactId>spring-boot-starter-thymeleaf
</artifactId>
</dependency>
异常页面
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="UTF-8">
<title>异常页面
</title>
</head>
<body>
<div th:text="${error}">
</div>
</body>
</html>
2.1 自定义异常类
package com
.tzb
.exception
;
import org
.springframework
.web
.bind
.annotation
.ControllerAdvice
;
import org
.springframework
.web
.bind
.annotation
.ExceptionHandler
;
import org
.springframework
.web
.multipart
.MaxUploadSizeExceededException
;
import org
.springframework
.web
.servlet
.ModelAndView
;
import javax
.servlet
.http
.HttpServletResponse
;
import java
.io
.IOException
;
import java
.io
.PrintWriter
;
@ControllerAdvice
public class MyException {
@ExceptionHandler(MaxUploadSizeExceededException
.class)
public ModelAndView
myCustomException(MaxUploadSizeExceededException e
) throws IOException
{
ModelAndView mv
= new ModelAndView();
mv
.addObject("error", "上传文件大小超出限制");
mv
.setViewName("myerror");
return mv
;
}
}
2.2 主页
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>多文件上传
</title>
</head>
<body>
<form action="/upload" method="post" enctype="multipart/form-data">
<input type="file" name="file"><br>
<input type="submit" value="提交">
</form>
</body>
</html>
2.3 Controller
package com
.tzb
.controller
;
import org
.springframework
.web
.bind
.annotation
.PostMapping
;
import org
.springframework
.web
.bind
.annotation
.RestController
;
import org
.springframework
.web
.multipart
.MultipartFile
;
import javax
.servlet
.http
.HttpServletRequest
;
import java
.io
.File
;
import java
.io
.IOException
;
import java
.text
.SimpleDateFormat
;
import java
.util
.Date
;
import java
.util
.SimpleTimeZone
;
import java
.util
.UUID
;
@RestController
public class FileUploadController {
SimpleDateFormat sdf
= new SimpleDateFormat("/yyyy/MM/dd/");
@PostMapping("/upload")
public String
upload(MultipartFile file
, HttpServletRequest req
) {
String format
= sdf
.format(new Date());
String realPath
= req
.getServletContext().getRealPath("/img") + format
;
File folder
= new File(realPath
);
if (!folder
.exists()) {
folder
.mkdirs();
}
String oldName
= file
.getOriginalFilename();
String newName
= UUID
.randomUUID().toString() + oldName
.substring(oldName
.lastIndexOf("."));
try {
file
.transferTo(new File(folder
, newName
));
String url
= req
.getScheme() + "://" + req
.getServerName() + ":" + req
.getServerPort() + "/img" + format
+ newName
;
return url
;
} catch (IOException e
) {
e
.printStackTrace();
}
return "error";
}
}
3 预设全局数据
在某个地方设置一个数据，这个数据在任意 Controller 都能访问到。
package com
.tzb
;
import org
.springframework
.web
.bind
.annotation
.ControllerAdvice
;
import org
.springframework
.web
.bind
.annotation
.ModelAttribute
;
import java
.util
.HashMap
;
import java
.util
.Map
;
@ControllerAdvice
public class GlobalData {
@ModelAttribute(value
= "info")
public Map
<String,Object> mydata(){
Map
<String, Object> map
= new HashMap<>();
map
.put("name", "Mike");
map
.put("addr", "Beijing");
return map
;
}
}
Controller
@RestController
public class HelloController {
@GetMapping("/hello")
public String
hello(Model model
){
Map
<String,Object> map
= model
.asMap();
Set
<String> keySet
= map
.keySet();
for (String key
: keySet
) {
System
.out
.println(key
+ ": "+ map
.get(key
));
}
return "success";
}
}
4 请求参数预处理
实体类
Controller
@RestController
public class BookController {
@PostMapping("/book")
public void addBook(@ModelAttribute("b") Book book
,@ModelAttribute("a") Author author
){
System
.out
.println(book
);
System
.out
.println(author
);
}
}
全局数据配置
package com
.tzb
;
import org
.springframework
.web
.bind
.WebDataBinder
;
import org
.springframework
.web
.bind
.annotation
.ControllerAdvice
;
import org
.springframework
.web
.bind
.annotation
.InitBinder
;
import org
.springframework
.web
.bind
.annotation
.ModelAttribute
;
import java
.util
.HashMap
;
import java
.util
.Map
;
@ControllerAdvice
public class GlobalData {
@InitBinder("a")
public void initA(WebDataBinder binder
){
binder
.setFieldDefaultPrefix("a.");
}
@InitBinder("b")
public void initB(WebDataBinder binder
){
binder
.setFieldDefaultPrefix("b.");
}
@ModelAttribute(value
= "info")
public Map
<String,Object> mydata(){
Map
<String, Object> map
= new HashMap<>();
map
.put("name", "Mike");
map
.put("addr", "Beijing");
return map
;
}
}
