No primary or default constructor found for ...Pageable

问题

报错如下Pageable没有主要或默认构造器。环境：springboot 2.2.1.RELEASE

报错日志

2019-11-28 10:10:10.898  INFO 18608 --- [           main] o.s.t.web.servlet.TestDispatcherServlet  : Completed initialization in 1 ms

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.IllegalStateException: No primary or default constructor found for interface org.springframework.data.domain.Pageable

	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014)
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:503)
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
	at org.springframework.test.web.servlet.TestDispatcherServlet.service(TestDispatcherServlet.java:72)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:590)
	at org.springframework.mock.web.MockFilterChain$ServletFilterProxy.doFilter(MockFilterChain.java:167)
	at org.springframework.mock.web.MockFilterChain.doFilter(MockFilterChain.java:134)
	at org.springframework.test.web.servlet.MockMvc.perform(MockMvc.java:183)
	at org.gallant.account.service.AccountInfoControllerTest.queryByPage(AccountInfoControllerTest.java:44)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.springframework.test.context.junit4.statements.RunBeforeTestExecutionCallbacks.evaluate(RunBeforeTestExecutionCallbacks.java:74)
	at org.springframework.test.context.junit4.statements.RunAfterTestExecutionCallbacks.evaluate(RunAfterTestExecutionCallbacks.java:84)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:75)
	at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:86)
	at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:84)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:251)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:97)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
	at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
	at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
	at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:190)
	at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
	at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
	at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
	at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
	at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Caused by: java.lang.IllegalStateException: No primary or default constructor found for interface org.springframework.data.domain.Pageable
	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:219)
	at org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor.createAttribute(ServletModelAttributeMethodProcessor.java:85)
	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.resolveArgument(ModelAttributeMethodProcessor.java:139)
	at org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:121)
	at org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:167)
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134)
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888)
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793)
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
	... 40 more
Caused by: java.lang.NoSuchMethodException: org.springframework.data.domain.Pageable.<init>()
	at java.lang.Class.getConstructor0(Class.java:3082)
	at java.lang.Class.getDeclaredConstructor(Class.java:2178)
	at org.springframework.web.method.annotation.ModelAttributeMethodProcessor.createAttribute(ModelAttributeMethodProcessor.java:216)
	... 52 more

配置文件

首先按照网上所说配置对应的类型解析器PageableHandlerMethodArgumentResolver

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
        // 注册Spring data jpa pageable的参数分解器
        argumentResolvers.add(new PageableHandlerMethodArgumentResolver());
    }
}

配置之后依然不生效，只能断点看源码查找原因。发现实际上下文中运行时解析器集合中压根没有我们追加的这个解析器（实际集合中的解析器列表见下图）。并且通过断点可以看到WebMvcConfig.addArgumentResolvers注册方法已经走到了，也就是扫描配置的路径与配置没问题。为什么？崩溃中

配置流程梳理WebMvcConfigurer

配置文件实现的该接口是在启用了MVC后回调增强配置使用的，即注解：@_EnableWebMvc。_查看EnableWebMvc注解中导入了Mvc配置类DelegatingWebMvcConfiguration。配置类中自动注入了所有WebMvcConfigurer类型配置用于回调增强。其父类WebMvcConfigurationSupport定义了各种bean。bean的定义中回调子类的get方法获取回调返回的增强配置。此时我们暂仅关心参数解析器配置部分requestMappingHandlerAdapter

@Autowired(required = false)
public void setConfigurers(List<WebMvcConfigurer> configurers) {
	if (!CollectionUtils.isEmpty(configurers)) {
		this.configurers.addWebMvcConfigurers(configurers);
	}
}

查看requestMappingHandlerAdapter注册时已经包含了我们自定义的PageableHandlerMethodArgumentResolver解析器并且是多出来了一个。所以我们可以删除多余的WebMvcConfigurer配置，将自定义的解析器追加至WebMvcConfigurationSupport.argumentResolvers，但是对于RequestMappingHandlerAdapter则是设置为了customArgumentResolvers。继续跟踪RequestMappingHandlerAdapter处理经过controller注解类中方法的request请求。可以看到该类中初始化提供了默认的解析器集合如下；正如我们上面截图中看到的解析器集合一样。下面我们可以看到自定义的customArgumentResolvers在不为空的时候回追加至argumentResolvers。

@Override
public void afterPropertiesSet() {
	...
	if (this.argumentResolvers == null) {
		List<HandlerMethodArgumentResolver> resolvers = getDefaultArgumentResolvers();
		this.argumentResolvers = new HandlerMethodArgumentResolverComposite().addResolvers(resolvers);
	}
	...
}
private List<HandlerMethodArgumentResolver> getDefaultArgumentResolvers() {
	List<HandlerMethodArgumentResolver> resolvers = new ArrayList<>();

	// Annotation-based argument resolution
	resolvers.add(new RequestParamMethodArgumentResolver(getBeanFactory(), false));
	resolvers.add(new RequestParamMapMethodArgumentResolver());
	resolvers.add(new PathVariableMethodArgumentResolver());
	resolvers.add(new PathVariableMapMethodArgumentResolver());
	resolvers.add(new MatrixVariableMethodArgumentResolver());
	resolvers.add(new MatrixVariableMapMethodArgumentResolver());
	resolvers.add(new ServletModelAttributeMethodProcessor(false));
	resolvers.add(new RequestResponseBodyMethodProcessor(getMessageConverters(), this.requestResponseBodyAdvice));
	resolvers.add(new RequestPartMethodArgumentResolver(getMessageConverters(), this.requestResponseBodyAdvice));
	resolvers.add(new RequestHeaderMethodArgumentResolver(getBeanFactory()));
	resolvers.add(new RequestHeaderMapMethodArgumentResolver());
	resolvers.add(new ServletCookieValueMethodArgumentResolver(getBeanFactory()));
	resolvers.add(new ExpressionValueMethodArgumentResolver(getBeanFactory()));
	resolvers.add(new SessionAttributeMethodArgumentResolver());
	resolvers.add(new RequestAttributeMethodArgumentResolver());

	// Type-based argument resolution
	resolvers.add(new ServletRequestMethodArgumentResolver());
	resolvers.add(new ServletResponseMethodArgumentResolver());
	resolvers.add(new HttpEntityMethodProcessor(getMessageConverters(), this.requestResponseBodyAdvice));
	resolvers.add(new RedirectAttributesMethodArgumentResolver());
	resolvers.add(new ModelMethodProcessor());
	resolvers.add(new MapMethodProcessor());
	resolvers.add(new ErrorsMethodArgumentResolver());
	resolvers.add(new SessionStatusMethodArgumentResolver());
	resolvers.add(new UriComponentsBuilderMethodArgumentResolver());

	// Custom arguments
	if (getCustomArgumentResolvers() != null) {
		resolvers.addAll(getCustomArgumentResolvers());
	}

	// Catch-all
	resolvers.add(new RequestParamMethodArgumentResolver(getBeanFactory(), true));
	resolvers.add(new ServletModelAttributeMethodProcessor(true));

	return resolvers;
}

断点跟踪发现初始化完成回调afterPropertiesSet时的RequestMappingHandlerAdapter是包含Pageable解析器的

但是requestMappingHandlerAdapter被创建了两次，并且看到回调invokeHandlerMethod方法时使用的是第二次创建的该bean，已经不包含我们之前看到的Pageable解析器。查看堆栈发现第二次初始化加载bean是由MockMvc的AbstractMockMvcBuilder对象发起的。也就是说mockMvc使用的是自己独立的应用上下文导致出现了我们所看到的异常场景。为了验证推论，我们正常启用应用，发现果然只有一次requestMappingHandlerAdapter创建而且正是我们所需要的bean。使用Advanced REST Client发送请求断点看到的拦截请求的handler中是存在我们所需要的Pageable解析器的，而且解析正常不会出现解析Pageable失败的异常。

问题总结

1. springboot2.x中已经不需要我们为了Pageable的解析再单独配置PageableHandlerMethodArgumentResolver
2. MockMvc的MockMvcBuilders.standaloneSetup(accountInfoController).build()构建事会初始化自己独立的应用上下文。如果使用Pageable参数可以自己根据需求添加配置

MockMvc mockMvc = MockMvcBuilders.standaloneSetup(accountInfoController).setCustomArgumentResolvers(new PageableHandlerMethodArgumentResolver()).build();