Java——反射调用类和方法时依赖注入失效问题排查与解决

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引言

  在开发过程中，使用反射进行类的方法调用时，遇到了依赖注入问题，通过demo进行问题复现和还原并记录。

基础代码

controller类

package com.test.selfcoding.controller;




import com.test.selfcoding.service.HelloWorldService;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * @Description controller
 * @Author LiaoJy
 * @Date 2023/6/22
 */
@RestController
@RequestMapping("/hello/world")
public class HelloWorldController {

    @Autowired
    private HelloWorldService helloWorldService;


    @GetMapping("")
    public String testGetHelloWorld() {
        return helloWorldService.getHelloWolrd();
    }

}

HelloWorldService类

package com.test.selfcoding.service.impl;




import com.test.selfcoding.service.HelloWorldService;

import com.test.selfcoding.utils.RandomStrUtils;
import com.test.selfcoding.utils.SpringContextUtil;
import lombok.SneakyThrows;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;


import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;


/**
 * @Description HelloWorldService
 * @Author LiaoJy
 * @Date 2023/6/22
 */
@Slf4j
@Service
public class HelloWorldService {

    public String getHelloWolrd() {
        String result = this.getStr("getHelloWolrd()");
        if (result.contains("hugh")) {
            String random = RandomStrUtils.getRandomStr(1);
            return result + random;
        }
        return "hi, someone, hello world!";
    }

    @SneakyThrows
    private String getStr(String methodName) {
        log.info("{} get str success.", methodName);
        return "hi " + this.getName() + " welcome!";
    }

    private String getName() throws ClassNotFoundException, NoSuchMethodException, InvocationTargetException, IllegalAccessException, InstantiationException {
        String classPath = "com.test.selfcoding.service.AaService";
        String methodName = "getBbStr";
        String param = "hugh";
        //TODO 反射调用AaService类
    }
}

AaService类

package com.test.selfcoding.service;





import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

/**
 * @Description AaService
 * @Author LiaoJy
 * @Date 2023/6/22
 */
@Service
public class AaService {

    @Autowired
    private BbService bbService;



    public String getBbStr(String s) {
        return s + bbService.getBbStr();
    }


}

BbService类

package com.test.selfcoding.service;





import org.springframework.stereotype.Service;

/**
 * @Description BbService
 * @Author LiaoJy
 * @Date 2023/6/22
 */
@Service
public class BbService {


    public String getBbStr() {
        return ", hello world！";
    }




}

反射实践

反射调用

在helloWorldService类中编写反射调用

private String getName() throws ClassNotFoundException, NoSuchMethodException, InvocationTargetException, IllegalAccessException, InstantiationException {
    String classPath = "com.test.selfcoding.service.AaService";
    String methodName = "getBbStr";
    String param = "hugh";
    //反射
    Class clazz = Class.forName(classPath);
    Method method = clazz.getMethod(methodName, String.class);
    Object obj = SpringContextUtil.getBean(clazz);
    String result = (String) method.invoke(obj, param);
    System.out.println("result: " + result);
    return result;
}

报错：未实例化

  1. 浏览器访问地址：http:localhost:8001/hello/world
    image.png
  2. 控制台报错：java.lang.IllegalArgumentException: object is not an instance of declaring class
java.lang.IllegalArgumentException: object is not an instance of declaring class
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_301]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_301]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_301]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_301]
	at com.test.selfcoding.service.impl.HelloWorldServiceImpl.getName(HelloWorldServiceImpl.java:47) ~[classes/:na]
	at com.test.selfcoding.service.impl.HelloWorldServiceImpl.getStr(HelloWorldServiceImpl.java:37) ~[classes/:na]
	at com.test.selfcoding.service.impl.HelloWorldServiceImpl.getHelloWolrd(HelloWorldServiceImpl.java:26) ~[classes/:na]
	at com.test.selfcoding.controller.HelloWorldController.testGetHelloWorld(HelloWorldController.java:23) ~[classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_301]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_301]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_301]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_301]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:655) ~[tomcat-embed-core-9.0.64.jar:4.0.FR]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) ~[tomcat-embed-core-9.0.64.jar:4.0.FR]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.21.jar:5.3.21]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.21.jar:5.3.21]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.21.jar:5.3.21]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1787) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_301]

尝试解决：进行实例化

Class clazz = Class.forName(classPath);

Method method = clazz.getMethod(methodName, String.class);

Object obj = clazz.newInstance();
String result = (String) method.invoke(obj, param);

报错：空指针

  1. 浏览器访问地址：http:localhost:8001/hello/world
    image.png
  2. 控制台报错：java.lang.NullPointerException: null
java.lang.NullPointerException: null
	at com.test.selfcoding.service.AaService.getBbStr(AaService.java:18) ~[classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_301]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_301]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_301]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_301]
	at com.test.selfcoding.service.impl.HelloWorldServiceImpl.getName(HelloWorldServiceImpl.java:48) ~[classes/:na]
	at com.test.selfcoding.service.impl.HelloWorldServiceImpl.getStr(HelloWorldServiceImpl.java:37) ~[classes/:na]
	at com.test.selfcoding.service.impl.HelloWorldServiceImpl.getHelloWolrd(HelloWorldServiceImpl.java:26) ~[classes/:na]
	at com.test.selfcoding.controller.HelloWorldController.testGetHelloWorld(HelloWorldController.java:23) ~[classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_301]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_301]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_301]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_301]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:150) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:117) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:895) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:808) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1067) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:655) ~[tomcat-embed-core-9.0.64.jar:4.0.FR]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.3.21.jar:5.3.21]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) ~[tomcat-embed-core-9.0.64.jar:4.0.FR]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.21.jar:5.3.21]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.21.jar:5.3.21]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.3.21.jar:5.3.21]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) ~[spring-web-5.3.21.jar:5.3.21]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) ~[tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1787) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.64.jar:9.0.64]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_301]

debug查看

image.png
bbService中未注入进来，为空。

排查bean是否有

查看启动时上下文context中的beanFactory-》beanDefinitionMap

image.png
有aaService和bbService

image.png

最终解决方案

反射调用时，在上下文中获取bean，解决依赖注入问题

SpringContextUtil工具类


/**
 * @Description 上下文工具类
 * @Author LiaoJy
 * @Date 2023/6/22
 */
@Component
public class SpringContextUtil implements ApplicationContextAware {


    private static ApplicationContext applicationContext;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        SpringContextUtil.applicationContext = applicationContext;
    }




    public static <T> T getBean(Class<T> clazz) {
        // 先判断是否存在上下文对象
        if (applicationContext == null) {
            return null;
        }
        return applicationContext.getBean(clazz);
    }

    public static <T> T getBean(String beanName, Class<T> clazz) {
        // 先判断是否存在上下文对象
        if (applicationContext == null) {
            return null;
        }
        return applicationContext.getBean(beanName, clazz);
    }

}

反射调用时通过上下文获取bean

Class clazz = Class.forName(classPath);

Method method = clazz.getMethod(methodName, String.class);

Object obj = SpringContextUtil.getBean(clazz);
String result = (String) method.invoke(obj, param);

运行结果

  1. 浏览器访问地址：http:localhost:8001/hello/world
    image.png
  2. 控制台信息
2023-06-22 18:07:29.189  INFO 19952 --- [nio-8001-exec-1] c.t.s.s.impl.HelloWorldServiceImpl       : getHelloWolrd() get str success.
result: hugh, hello world！

至此，问题解决！

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