import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.annotation.Autowired;

import java.lang.reflect.Proxy;

/**
 * @Title：相對(duì)于BeanFactory這個(gè)大工廠,這是一個(gè)小工廠，專門(mén)用于創(chuàng)建某種類型的bean(默認(rèn)創(chuàng)建的是單例bean)
 * @Description 創(chuàng)建代理對(duì)象
 * @Version
 */
public class HttpProxyFactoryBean<T> implements FactoryBean<T> {

    /**
     *【注意】
     * 這里之所以可以進(jìn)行自動(dòng)裝配，是因?yàn)楫?dāng)前的這個(gè)HttpProxyFactoryBean是會(huì)被注冊(cè)到Spring中的
     * 只不過(guò)它的注冊(cè)方式 跟一般的不一樣（一般會(huì)在類上，加一個(gè)如@Component、@Service這樣的注解 ）
     * 它是通過(guò)注冊(cè)BeanDefinition的方式注冊(cè)的，可能會(huì)注冊(cè)多個(gè)，而其中的每一個(gè)HttpProxyFactoryBean實(shí)例都會(huì)被自動(dòng)裝配同一個(gè)HttpProxyInvocationHandler實(shí)例
     *
     * 也有等價(jià)的做法是：
     * 利用ApplicationContextAware接口的setApplicationContext獲取到applicationContext，
     * 然后把a(bǔ)pplicationContext 作為屬性設(shè)置到當(dāng)前類中
     *  再利用applicationContext的getBean方法來(lái)獲取InvocationHandler的實(shí)例
     */
    @Autowired
    private HttpProxyInvocationHandler httpProxyInvocationHandler;

    private Class<T> rpcInterface;

    public HttpProxyFactoryBean(Class<T> rpcInterface){
        this.rpcInterface = rpcInterface;
    }


    @Override
    public T getObject() throws Exception {
        //這里應(yīng)該放ComputerService接口
        return (T)Proxy.newProxyInstance(rpcInterface.getClassLoader(),new Class[]{rpcInterface} ,httpProxyInvocationHandler);
    }

    @Override
    public Class<?> getObjectType() {
        return rpcInterface;
    }

}

import cn.hutool.http.HttpRequest;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

/**
 * @Description 把服務(wù)方法的調(diào)用轉(zhuǎn)換為對(duì)遠(yuǎn)程服務(wù)的http請(qǐng)求
 * @Version
 */
@Component
public class HttpProxyInvocationHandler implements InvocationHandler {

    @Value("${proxy.serverUrl}")
    private String serverUrl;

    @Value("${proxy.project}")
    private String serverProject;

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        Class<?> declaringClass = method.getDeclaringClass();
        if (Object.class.equals(declaringClass)) {
            return method.invoke(this, args);
        }

        String methodName = method.getName();
        String name = method.getDeclaringClass().getName();

        //拼接請(qǐng)求地址
        String url = serverUrl + name + "/" + methodName;
//        String url = "http://test:8080/soa/com.rdd.TestService/createActivity";
        HashMap<String, String> paramMap = new HashMap<>();
    
//        String result = HttpRequest.post(url).headerMap(paramMap, true).body("[" + JSONObject.toJSONString(args) + "]").execute().body();
        String result = HttpRequest.post(url).headerMap(paramMap, true).body(JSONObject.toJSONString(args)).execute().body();

        System.out.println(">>>" + url + "的響應(yīng)結(jié)果為:" + result);

        //將響應(yīng)結(jié)果轉(zhuǎn)換為接口方法的返回值類型
        Class<?> returnType = method.getReturnType();
        if (returnType.isPrimitive() || String.class.isAssignableFrom(returnType)) {
            if (returnType == int.class || returnType == Integer.class) {
                return Integer.valueOf(result);
            } else if (returnType == long.class || returnType == Long.class) {
                return Long.valueOf(result);
            }
            return result;
        } else if (Collection.class.isAssignableFrom(returnType)) {
            return JSONArray.parseArray(result, Object.class);
        } else if (Map.class.isAssignableFrom(returnType)) {
            return JSON.parseObject(result, Map.class);
        } else {
            return JSONObject.parseObject(result, returnType);
        }
    }
}

import cn.hutool.core.io.file.FileReader;
import org.apache.commons.lang.StringUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.*;
import org.springframework.context.annotation.PropertySource;
import org.springframework.stereotype.Component;

import java.util.HashSet;
import java.util.List;
import java.util.Set;

/**
 * @Title：bean工廠的后置處理器，用于動(dòng)態(tài)注冊(cè)bean
 * @Date 2021/3/23 10:13
 * @Description
 * @Version
 */
@Component
@PropertySource("classpath:application.properties")
public class HttpProxyRegistryPostProcessor implements BeanDefinitionRegistryPostProcessor {

    /**
     * 該方法用來(lái)注冊(cè)更多的bean到spring容器中
     *
     * @param beanDefinitionRegistry
     * @throws BeansException
     */
    @Override
    public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry beanDefinitionRegistry) throws BeansException {
        //默認(rèn)UTF-8編碼，可以在構(gòu)造中傳入第二個(gè)參數(shù)做為編碼
        FileReader fileReader = new FileReader("proxy.txt");
        List<String> classStrList = fileReader.readLines();
        Set<Class<?>> proxyClazzSet = new HashSet<>();
        for (String s : classStrList) {
            if (StringUtils.isBlank(s)) {
                continue;
            }
            try {
                Class<?> aClass = Class.forName(s);
                proxyClazzSet.add(aClass);
            } catch (ClassNotFoundException e) {
                e.printStackTrace();
            }
        }

        for (Class<?> targetClazz : proxyClazzSet) {
            BeanDefinitionBuilder beanDefinitionBuilder = BeanDefinitionBuilder.genericBeanDefinition(targetClazz);
            GenericBeanDefinition definition = (GenericBeanDefinition) beanDefinitionBuilder.getRawBeanDefinition();
            //設(shè)置構(gòu)造方法的參數(shù)  對(duì)于Class<?>,既可以設(shè)置為Class,也可以傳Class的完全類名
            //definition.getConstructorArgumentValues().addGenericArgumentValue(targetClazz);
            definition.getConstructorArgumentValues().addGenericArgumentValue(targetClazz.getName());

            //Bean的類型，指定為某個(gè)代理接口的類型
            definition.setBeanClass(HttpProxyFactoryBean.class);
            //表示 根據(jù)代理接口的類型來(lái)自動(dòng)裝配
            definition.setAutowireMode(AbstractBeanDefinition.AUTOWIRE_BY_TYPE);
            beanDefinitionRegistry.registerBeanDefinition(targetClazz.getName(),definition);
        }
    }

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory configurableListableBeanFactory) throws BeansException {

    }
}