SpringBoot报错：Failed to instantiate [java.util.List]: Specified class is an interface解决

Dear 丶 2024-04-03 11:29 19阅读 0赞

## 报错 ##

Failed to instantiate [java.util.List]: Specified class is an interface

> **原因：因为指定的参数是一个接口，无法实例化 \[java.util.List\]。**

完整报错如下：

Failed to instantiate [java.util.List]: Specified class is an interface
    org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:99)
    org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:141)
    org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor.createAttribute(ServletModelAttributeMethodProcessor.java:81)
    org.springframework.web.method.annotation.ModelAttributeMethodProcessor.resolveArgument(ModelAttributeMethodProcessor.java:101)
    org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:121)
    org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:158)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:128)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    org.springframework.boot.web.filter.ApplicationContextHeaderFilter.doFilterInternal(ApplicationContextHeaderFilter.java:55)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:123)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:110)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    org.springframework.boot.actuate.autoconfigure.MetricsFilter.doFilterInternal(MetricsFilter.java:106)
    org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
    org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
    org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
    org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
    org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
    org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:478)
    org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
    org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80)
    org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
    org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
    org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:799)
    org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
    org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:861)
    org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1455)
    org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
    java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    java.lang.Thread.run(Thread.java:745)

## 解决 ##

1、当List<>中的泛型是一个自定义类时使用`@RequestBody` ，示例如下

test(@RequestBody List<TestDTO> list)

2、当List<>中的泛型是String或其它基本数据类型（或者基本数据类型的包装类）时使用`@RequestParam`，示例如下

test(@RequestParam  List<Long> ids)

## 扩展 ##

在SpringMvc后台进行获取数据，一般有三种：

> 1.request.getParameter(“参数名”)
> 
> 2.用@RequestParam注解获取
> 
> 3.Springmvc默认支持的数据类型接收参数，可直接通过controller方法参数对应jsp中请求参数name直接获取

![在这里插入图片描述][5e1b731011d04f1b8b5bb34319048090.png]

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[5e1b731011d04f1b8b5bb34319048090.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/03/769da038ed374155999ed390a656e794.png