1.自定义注解

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Post {
    String value();
}

@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
public @interface Field {
    String value();
}

2.定义callback

public interface ICallBack<T> {

    void successed(T t);

    void failed(Exception exception);
}

3.定义返回的对象

public class AppInfo {

    private String appName;
    private String appVersion;

}

4.定义动态代理获取方法上的注解和方法上的参数注解

package annomation;

import typeinfo.Log;

import java.lang.annotation.Annotation;
import java.lang.reflect.*;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * Created by xiaoma on 2017/7/18.
 */
public class CreateServiceFactory {

    public static <T> T createService(Class<T> clazz) {
        return (T) Proxy.newProxyInstance(clazz.getClassLoader(), new Class[]{clazz},
                new InvocationHandler() {
                    @Override
                    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                        //获取方法上的注解内容
                        getRequestType(method);
                        //获取方法的参数及类型
                        getRequestParams(method, args);
                        //获取最后一个Callback及返回实例
                        getCallbackInfo(method, args);
                        return null;
                    }
                });
    }

    private static void getCallbackInfo(Method method, Object[] args) {
        Type[] types = method.getGenericParameterTypes();
        //最后一个是Callback类型
        Type type = types[types.length - 1];
        Object obj = args[types.length - 1];
        Type responseType;
        if (obj instanceof ICallBack) {
            if (type instanceof ParameterizedType) {
                ParameterizedType ptype = (ParameterizedType) type;
                responseType = ptype.getActualTypeArguments()[0];
                ICallBack callBack = (ICallBack) obj;
                Log.sop("responseType=" + responseType + "=callback=" + callBack);
            }
        }
    }

    private static void getRequestParams(Method method, Object[] args) {
        Map<String, String> paramsMap = new LinkedHashMap<>();
        Annotation[][] parameterAnnotations = method.getParameterAnnotations();
        Type[] parameterTypes = method.getGenericParameterTypes();
        int j = 0;
        int length = parameterAnnotations.length;
        for (int i = 0; i < length - 1; i++) {
            Annotation[] annotation = parameterAnnotations[i];
            if (annotation != null) {
                for (Annotation anno : annotation) {
                    if (anno instanceof Field) {
                        String key = ((Field) anno).value();
                        paramsMap.put(key, String.valueOf(args[j]));
                        Log.sop("key=" + key + "=value=" + args[j]);
                    }
                }
            }
            j++;
        }
    }

    private static void getRequestType(Method method) {
        Annotation[] annotations = method.getAnnotations();
        for (Annotation annotation : method.getAnnotations()) {
            if (annotation instanceof Post) {
                String type = ((Post) annotation).value();
                Log.sop("请求方式=" + type);
            }
        }
    }
}

5.定义接口

public interface Login {

    @Post("/xiaoma/post")
     void getInfo(@Field(value = "version") String version,@Field(value = "info") String inf,ICallBack<AppInfo> callBack);
}

6.测试

public class TestAnnomation {

    public static void main(String[] args){
        Log.sop("注解测试");
        Login login = CreateServiceFactory.createService(Login.class);
        login.getInfo("xiaoma", "android", new ICallBack<AppInfo>() {
            @Override
            public void successed(AppInfo appInfo) {

            }

            @Override
            public void failed(Exception exception) {

            }
        });
    }

}

7.测试结果

注解测试
请求方式=/xiaoma/post
key=version=value=xiaoma
key=info=value=android
responseType=class annomation.AppInfo=callback=annomation.TestAnnomation$1@1d44bcfa