No primary or default constructor found for ...Pageable

問題

報錯如下Pageable沒有主要或默認構造器。環境：springboot 2.2.1.RELEASE

報錯日誌

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

首先按照網上所說配置對應的類型解析器PageableHandlerMethodArgumentResolver

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
    @Override
    public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
        // 註冊Spring data jpa pageable的參數分解器
        argumentResolvers.add(new PageableHandlerMethodArgumentResolver());
    }
}

配置之後依然不生效，只能斷點看源碼查找原因。發現實際上下文中運行時解析器集合中壓根沒有我們追加的這個解析器（實際集合中的解析器列表見下圖）。並且通過斷點可以看到WebMvcConfig.addArgumentResolvers註冊方法已經走到了，也就是掃描配置的路徑與配置沒問題。爲什麼？崩潰中

配置流程梳理WebMvcConfigurer

配置文件實現的該接口是在啓用了MVC後回調增強配置使用的，即註解：@_EnableWebMvc。_查看EnableWebMvc註解中導入了Mvc配置類DelegatingWebMvcConfiguration。配置類中自動注入了所有WebMvcConfigurer類型配置用於回調增強。其父類WebMvcConfigurationSupport定義了各種bean。bean的定義中回調子類的get方法獲取回調返回的增強配置。此時我們暫僅關心參數解析器配置部分requestMappingHandlerAdapter

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

查看requestMappingHandlerAdapter註冊時已經包含了我們自定義的PageableHandlerMethodArgumentResolver解析器並且是多出來了一個。所以我們可以刪除多餘的WebMvcConfigurer配置，將自定義的解析器追加至WebMvcConfigurationSupport.argumentResolvers，但是對於RequestMappingHandlerAdapter則是設置爲了customArgumentResolvers。繼續跟蹤RequestMappingHandlerAdapter處理經過controller註解類中方法的request請求。可以看到該類中初始化提供了默認的解析器集合如下；正如我們上面截圖中看到的解析器集合一樣。下面我們可以看到自定義的customArgumentResolvers在不爲空的時候回追加至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;
}

斷點跟蹤發現初始化完成回調afterPropertiesSet時的RequestMappingHandlerAdapter是包含Pageable解析器的

但是requestMappingHandlerAdapter被創建了兩次，並且看到回調invokeHandlerMethod方法時使用的是第二次創建的該bean，已經不包含我們之前看到的Pageable解析器。查看堆棧發現第二次初始化加載bean是由MockMvc的AbstractMockMvcBuilder對象發起的。也就是說mockMvc使用的是自己獨立的應用上下文導致出現了我們所看到的異常場景。爲了驗證推論，我們正常啓用應用，發現果然只有一次requestMappingHandlerAdapter創建而且正是我們所需要的bean。使用Advanced REST Client發送請求斷點看到的攔截請求的handler中是存在我們所需要的Pageable解析器的，而且解析正常不會出現解析Pageable失敗的異常。

問題總結

1. springboot2.x中已經不需要我們爲了Pageable的解析再單獨配置PageableHandlerMethodArgumentResolver
2. MockMvc的MockMvcBuilders.standaloneSetup(accountInfoController).build()構建事會初始化自己獨立的應用上下文。如果使用Pageable參數可以自己根據需求添加配置

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