这篇文章主要讲解了“SpringBean和Controller如何实现动态注册与注销”，文中的讲解内容简单清晰，易于学习与理解，下面请大家跟着小编的思路慢慢深入，一起来研究和学习“SpringBean和Controller如何实现动态注册与注销”吧！
部分场景下可能需要下载远程jar包，然后注册jar包中的Bean和Controller
说明
这里的Bean 一般特指 Service层的服务类，Controller本质上也是Bean
注册和注销工具类
这里用了一些 hutool的工具类，hutools是一个不错的基础工具集。
package cn.guzt.utils;
import cn.hutool.extra.spring.SpringUtil;
import org.springframework.beans.factory.support.BeanDefinitionBuilder;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.util.ClassUtils;
import org.springframework.util.ReflectionUtils;
import org.springframework.web.servlet.mvc.method.RequestMappingInfo;
import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping;
import java.lang.reflect.Method;
/**
* 动态注册注销Spring Bean
*
* @author guzt
*/
@SuppressWarnings("unused")
public class DynamicRegistUtil {
/**
* 动态注册Bean
*
* @param beanName bean名称
* @param targetClass bean对应的类
*/
public static void registerBeanDefinition(String beanName, Class<?> targetClass) {
ApplicationContext applicationContext = SpringUtil.getApplicationContext();
//获取BeanFactory
DefaultListableBeanFactory defaultListableBeanFactory =
(DefaultListableBeanFactory) applicationContext.getAutowireCapableBeanFactory();
//创建bean信息.
BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder.genericBeanDefinition(targetClass);
//动态注册bean.
defaultListableBeanFactory.registerBeanDefinition(beanName, beanDefinitionBuilder.getBeanDefinition());
}
/**
* 动态卸载Bean
*
* @param beanName bean名称
*/
public static void unRegisterBeanDefinition(String beanName) {
ApplicationContext applicationContext = SpringUtil.getApplicationContext();
if (!applicationContext.containsBean(beanName)) {
return;
}
//获取BeanFactory
DefaultListableBeanFactory defaultListableBeanFactory =
(DefaultListableBeanFactory) applicationContext.getAutowireCapableBeanFactory();
defaultListableBeanFactory.removeBeanDefinition(beanName);
}
/**
* 动态注册Controller
*
* @param controllerBeanName controller的beanName
* @throws Exception 反射异常
*/
public static void registerController(String controllerBeanName)
throws Exception {
final RequestMappingHandlerMapping requestMappingHandlerMapping =
SpringUtil.getBean(RequestMappingHandlerMapping.class);
if (requestMappingHandlerMapping != null) {
Object controller = SpringUtil.getBean(controllerBeanName);
if (controller == null) {
return;
}
//注册Controller
Method method = requestMappingHandlerMapping.getClass().getSuperclass().getSuperclass().
getDeclaredMethod("detectHandlerMethods", Object.class);
//将private改为可使用
method.setAccessible(true);
method.invoke(requestMappingHandlerMapping, controllerBeanName);
}
}
/**
* 动态去掉Controller的Mapping
*
* @param controllerBeanName controller的beanName
*/
public static void unregisterController(String controllerBeanName) {
final RequestMappingHandlerMapping requestMappingHandlerMapping
= SpringUtil.getBean("requestMappingHandlerMapping");
if (requestMappingHandlerMapping != null) {
Object controller = SpringUtil.getBean(controllerBeanName);
if (controller == null) {
return;
}
final Class<?> targetClass = controller.getClass();
ReflectionUtils.doWithMethods(targetClass, method -> {
Method specificMethod = ClassUtils.getMostSpecificMethod(method, targetClass);
try {
Method createMappingMethod = RequestMappingHandlerMapping.class.
getDeclaredMethod("getMappingForMethod", Method.class, Class.class);
createMappingMethod.setAccessible(true);
RequestMappingInfo requestMappingInfo = (RequestMappingInfo)
createMappingMethod.invoke(requestMappingHandlerMapping, specificMethod, targetClass);
if (requestMappingInfo != null) {
requestMappingHandlerMapping.unregisterMapping(requestMappingInfo);
}
} catch (Exception e) {
e.printStackTrace();
}
}, ReflectionUtils.USER_DECLARED_METHODS);
}
}
}编写测试用例
创建一个maven项目(dynamic-regist-bean)，里面主要引入spring-boot-starter-web即可
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency>
创建一个service测试类
package org.example.service;
public interface DynamicRegistService {
void serviceDo();
}创建接口对应的实现类，上面无需@Service 注解
package org.example.service.impl;
import lombok.extern.slf4j.Slf4j;
import org.example.service.DynamicRegistService;
@Slf4j
public class DynamicRegistServiceImpl implements DynamicRegistService {
@Override
public void serviceDo() {
log.info("Spring动态注册的Bean dynamicRegistServiceImpl中的 serviceDo 无参方法执行完成...");
}
}创建一个controller测试类，类上面无需 @Controller注解
package org.example.controller;
import org.springframework.web.bind.annotation.*;
import java.util.HashMap;
import java.util.Map;
@ResponseBody
@RequestMapping("dynamicRegistController")
public class DynamicRegistController {
@PostMapping("postTest")
public Map<String, Object> postTest(@RequestBody Map<String, Object> params) {
Map<String, Object> map = new HashMap<>(4);
map.put("code", "0");
map.put("msg", "POST请求测试成功, 传递参数params:" + params.toString());
map.put("data", "");
return map;
}
@GetMapping("getTest/{id}")
public Map<String, Object> getTest(@PathVariable("id") String id) {
Map<String, Object> map = new HashMap<>(4);
map.put("code", "0");
map.put("msg", "GET请求测试成功, 传输的参数id:" + id);
map.put("data", "");
return map;
}
}编译打包
> maven clean package
mavne打包命令生成 dynamic-regist-bean.jar
另外一个SpringBoot中创建测试接口
假设访问BaseUrl为： http://localhost:8081
import cn.guzt.utils.DynamicRegistUtil;
import cn.hutool.core.util.ClassLoaderUtil;
import cn.hutool.core.util.ReflectUtil;
import cn.hutool.extra.spring.SpringUtil;
import com.middol.starter.common.pojo.vo.NoBody;
import com.middol.starter.common.pojo.vo.ResponseVO;
import io.swagger.annotations.Api;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.io.File;
@Api(tags = "动态注册Bean、Controller测试")
@RestController
@RequestMapping("dynamicRegistTestController")
public class DynamicRegistTestController {
private static final Logger logger = LoggerFactory.getLogger(DynamicRegistTestController.class);
/**
* 模拟从远程下载准备要注册Bean的jar文件
*
* @return jar文件
*/
private File getRmoteJarFile() {
return new File("E:/IDEA_HOME/dynamic-regist-bean/dynamic-regist-bean/target/dynamic-regist-bean.jar");
}
@GetMapping("registBean")
public ResponseVO<NoBody> registBean() {
File jarFile = getRmoteJarFile();
// 准备要注册的Bean类名
String className = "org.example.service.impl.DynamicRegistServiceImpl";
// 准备要注册的Bean名称
String beanName = "dynamicRegistServiceImpl";
// 注册完成后调用Bean的测试方法
String invokeMethod = "serviceDo";
Class<?> targetClass = ClassLoaderUtil.loadClass(jarFile, className);
logger.info("本次要注册的bean className = {}", targetClass.getName());
DynamicRegistUtil.registerBeanDefinition(beanName, targetClass);
Object object = SpringUtil.getBean(beanName);
ReflectUtil.invoke(object, invokeMethod);
return ResponseVO.success();
}
@GetMapping("unRegistBean")
public ResponseVO<NoBody> unRegistBean() {
String beanName = "dynamicRegistServiceImpl";
logger.info("本次要卸载的bean beanName = {}", beanName);
DynamicRegistUtil.unRegisterBeanDefinition(beanName);
logger.info("卸载结果：{}", SpringUtil.getApplicationContext().containsBean(beanName) ? "失败" : "成功");
return ResponseVO.success();
}
@GetMapping("registController")
public ResponseVO<NoBody> registController() throws Exception {
File jarFile = getRmoteJarFile();
// 准备要注册的Bean类名
String className = "org.example.controller.DynamicRegistController";
// 准备要注册的Bean名称
String beanName = "dynamicRegistController";
Class<?> targetClass = ClassLoaderUtil.loadClass(jarFile, className);
logger.info("本次要注册的controller className = {}", targetClass.getName());
DynamicRegistUtil.registerBeanDefinition(beanName, targetClass);
DynamicRegistUtil.registerController(beanName);
return ResponseVO.success();
}
@GetMapping("unRegistController")
public ResponseVO<NoBody> unRegistController() {
String beanName = "dynamicRegistController";
logger.info("本次要卸载的Controller beanName = {}", beanName);
DynamicRegistUtil.unregisterController(beanName);
DynamicRegistUtil.unRegisterBeanDefinition(beanName);
logger.info("卸载结果：{}", SpringUtil.getApplicationContext().containsBean(beanName) ? "失败" : "成功");
return ResponseVO.success();
}
}测试结果
注册Service
访问： http://localhost:8081/dynamicRegistTestController/registBean
返回：
{"code":"0","message":"SUCCESS","data":null}日志：
[http-nio-8081-exec-1] c.g.c.DynamicRegistTestController : 本次要注册的bean className = org.example.service.impl.DynamicRegistServiceImpl
[http-nio-8081-exec-1] o.e.s.impl.DynamicRegistServiceImpl : Spring动态注册的Bean dynamicRegistServiceImpl中的 serviceDo 无参方法执行完成...
注册controller
访问：http://localhost:8081/dynamicRegistTestController/registController
返回：
{"code":"0","message":"SUCCESS","data":null}日志：
[http-nio-8081-exec-5] c.g.c.DynamicRegistTestController : 本次要注册的controller className = org.example.controller.DynamicRegistController
测试Controller 是否真的注册成功：
访问： http://localhost:8081/dynamicRegistController/getTest/aaaa 返回：
{"msg":"GET请求测试成功, 传输的参数id:aaaa","data":"","code":"0"}注销Controller
访问：http://localhost:8081/dynamicRegistTestController/unRegistController
然后重新访问： http://localhost:8081/dynamicRegistController/getTest/aaaa
返回：404错误 ，说明注销成功！
Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.Tue Feb 07 14:14:52 CST 2023
There was an unexpected error (type=Not Found, status=404).