SpringBoot @ControllerAdvice的三种使用场景
1.概述
@ControllerAdvice 有三个方面的功能：
- 全局异常处理
- 全局数据绑定
- 全局数据预处理
2.全局异常处理
（一）返回字符串
MyGlobalException.java
package com.zhuantai.fileupload.controller;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.multipart.MaxUploadSizeExceededException;
/**
* 全局异常处理类
* @author ANTIA1
* @date 2021/7/7 23:21
*/
//@ControllerAdvice //@Controller 返回视图
@RestControllerAdvice //@RestController 返回JSON数据...
public class MyGlobalException {
@ExceptionHandler(MaxUploadSizeExceededException.class)
public String customException(MaxUploadSizeExceededException e){
return "上传文件大小超出限制";
}
}
01.html
<!DOCTYPE html>
<html lang="zh">
<head>
<title>Title</title>
</head>
<body>
<form action="/upload" method="post" enctype="multipart/form-data">
<input type="file" name="file">
<input type="submit" value="上传">
</form>
</body>
</html>
application.properties
# 应用名称
spring.application.name=fileupload
# 应用服务 WEB 访问端口
server.port=8080
# 设置文件最大值
spring.servlet.multipart.max-file-size=1KB
运行结果：
（二）返回页面
MyGlobalException.java
package com.zhuantai.fileupload.controller;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;
import org.springframework.web.multipart.MaxUploadSizeExceededException;
import org.springframework.web.servlet.ModelAndView;
/**
* 全局异常处理类
* @author ANTIA1
* @date 2021/7/7 23:21
*/
@ControllerAdvice //@Controller 返回视图
public class MyGlobalException {
@ExceptionHandler(MaxUploadSizeExceededException.class)
public ModelAndView customException(MaxUploadSizeExceededException e) {
ModelAndView mv = new ModelAndView("zhuantai");
mv.addObject("error", e.getMessage());
return mv;
}
}
01.html
<!DOCTYPE html>
<html lang="zh">
<head>
<title>Title</title>
</head>
<body>
<form action="/upload" method="post" enctype="multipart/form-data">
<input type="file" name="file">
<input type="submit" value="上传">
</form>
</body>
</html>
templates/zhuantai.html
<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
<title>Title</title>
</head>
<body>
<h1>zhuantai-thymeleaf</h1>
<div th:text="${error}"></div>
</body>
</html>
运行结果：
3.全局数据绑定
MyGlobalData.java
package com.zhuantai.controlleradvice;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ModelAttribute;
import java.util.HashMap;
import java.util.Map;
/**
* 全局数据绑定
* @author ANTIA1
* @date 2021/7/8 0:06
*/
@ControllerAdvice
public class MyGlobalData {
@ModelAttribute("info")//不定义名称默认为map
public Map<String,String> myData(){
Map<String,String> info = new HashMap<>();
info.put("username","zhuantai");
info.put("address","antia1.top");
return info;
}
}
HelloController.java
package com.zhuantai.controlleradvice;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.Map;
/**
* @author ANTIA1
* @date 2021/7/8 0:10
*/
@RestController
public class HelloController {
@GetMapping("/hello")
public void hello(Model model){
Map<String, Object> asMap = model.asMap();
Map<String,String> info = (Map<String, String>) asMap.get("info");
for (String s : info.keySet()){
System.out.println("s = " + s);
}
}
}
运行结果：
4.全局数据预处理
MyGlobalData.java
package com.zhuantai.controlleradvice;
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;
/**
* 全局数据绑定
* @author ANTIA1
* @date 2021/7/8 0:06
*/
@ControllerAdvice
public class MyGlobalData {
@InitBinder("b")
public void b(WebDataBinder binder){
binder.setFieldDefaultPrefix("b.");//设置一个默认的前缀
}
@InitBinder("a")
public void a(WebDataBinder binder){
binder.setFieldDefaultPrefix("a.");//设置一个默认的前缀
}
}
BookController.java
package com.zhuantai.controlleradvice;
import com.zhuantai.controlleradvice.model.Author;
import com.zhuantai.controlleradvice.model.Book;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PostMapping;
/**
* @author ANTIA1
* @date 2021/7/8 0:18
*/
@Controller
public class BookController {
@PostMapping("/book")
public void addBook(@ModelAttribute("b") Book book, @ModelAttribute("a") Author author){
System.out.println("book = " + book);
System.out.println("author = " + author);
}
}
Book.java
package com.zhuantai.controlleradvice.model;
/**
* @author ANTIA1
* @date 2021/7/8 0:17
*/
public class Book {
private String name;
private Double price;
public Book(String name, Double price) {
this.name = name;
this.price = price;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Double getPrice() {
return price;
}
public void setPrice(Double price) {
this.price = price;
}
@Override
public String toString() {
return "Book{" +
"name='" + name + '\'' +
", price=" + price +
'}';
}
}
Author.java
package com.zhuantai.controlleradvice.model;
/**
* @author ANTIA1
* @date 2021/7/8 0:18
*/
public class Author {
private String name;
private Integer age;
public Author(String name, Integer age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "Author{" +
"name='" + name + '\'' +
", age=" + age +
'}';
}
}
测试：
运行结果：