1. 创建注解

@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Component
public @interface Match {String value();
}

2. 处理 match 的工具类

import com.google.common.collect.Maps;
import org.apache.commons.collections4.MapUtils;
import org.springframework.aop.support.AopUtils;
import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Component;import javax.annotation.Resource;
import java.lang.reflect.InvocationTargetException;
import java.util.Iterator;
import java.util.Map;/*** @date:2024/3/5*/
@Component
public class HandlerMatcher {private LazyMap<Class, Map<String, Object>> handlerPool;private Matcher equalMatcher;@Resourceprivate ApplicationContext applicationContext;public HandlerMatcher(ApplicationContext applicationContext) {this.handlerPool = new NamelessClass();this.equalMatcher = new DefaultMatcher(null);this.applicationContext = applicationContext;}public <T> T match(Class<T> targetClass, String key) {return this.match(targetClass, key, this.equalMatcher);}public <T> T match(Class<T> handlerClass, String key, Matcher matcher) {Map<String, Object> map =this.handlerPool.get(handlerClass);if (MapUtils.isEmpty(map)) {return null;} else {return (T) matcher.match(map, key);}}private <T> Map<String, T> getHandlers(Class<T> contract) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {Map<String, T> handlerMap = Maps.newHashMap();Map<String, T> beanMap = this.applicationContext.getBeansOfType(contract);Iterator var4 = beanMap.entrySet().iterator();while (var4.hasNext()) {Map.Entry<String, T> entry = (Map.Entry) var4.next();T handler = entry.getValue();Class clazz = !AopUtils.isAopProxy(handler) && !AopUtils.isCglibProxy(handler) ? handler.getClass() : AopUtils.getTargetClass(handler);Match match = (Match) clazz.getAnnotation(Match.class);if (match != null) {handlerMap.put(match.value(), handler);}}return handlerMap;}private class DefaultMatcher implements Matcher<Object, Object> {private DefaultMatcher() {}public DefaultMatcher(NamelessClass namelessClass) {}@Overridepublic Object match(Map<Object, Object> map, Object key) {return map.get(key);}}class NamelessClass extends LazyMap<Class, Map<String, Object>> {NamelessClass() {}@Overrideprotected Map<String, Object> load(Class key) {try {return HandlerMatcher.this.getHandlers(key);} catch (Exception var3) {throw new RuntimeException(var3);}}}}

3. LazyMap 类

public abstract class LazyMap<K, V> {private ConcurrentMap<K, V> map = Maps.newConcurrentMap();public LazyMap() {}public V get(K key) {V value = this.map.get(key);if (value != null) {return value;} else {value = this.load(key);V existsValue = value == null ? null : this.map.putIfAbsent(key, value);return existsValue == null ? value : existsValue;}}protected abstract V load(K var1);
}

4. 适配方法接口

public interface Matcher<T, F> {T match(Map<Object, Object> var1, F var2);
}

5. 定义适配器接口

public interface TemplateBuilderInterface {String build(String Type);
}

6. 实现适配器的具体类

@Match("xml")
public class XmlBuilderInterface implements TemplateBuilderInterface {@Overridepublic String build(String Type) {return "xml";}
}@Match("json")
public class JsonBuilderInterface implements TemplateBuilderInterface {@Overridepublic String build(String Type) {return "json";}
}

7. 调用方法

@Service
public class MatchService {@Resourceprivate HandlerMatcher handlerMatcher;public String match(String content,String type){TemplateBuilderInterface builder = handlerMatcher.match(TemplateBuilderInterface.class,type);return builder.build(content);}
}

8. 测试 controller

    @RequestMapping("match")@ResponseBodypublic String match(String type) {return matchService.match("test",type);}

9. 演示效果：

请求：ip:port/test/match?type=json
返回： json

请求：ip:port/test/match?type=xml
返回：xml