即使我知道 foo 不为空这一事实,该断言也能编译但失败:
import static org.hamcrest.Matchers.is; // see http://stackoverflow.com/a/27256498/2848676
import static org.hamcrest.Matchers.not;
import static org.hamcrest.MatcherAssert.assertThat;
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...
assertThat(foo, is(not(null)));
Run Code Online (Sandbox Code Playgroud) 我有一个地图,Map<String, Object> map = new HashMap<>(); 我在此地图中存储多种类型的数据。1.) 原始类型 2.) 用户定义类的对象作为此映射中的值。当我将任何原始类型值转换为对象并存储在 Map 中时,它工作正常,但在用户定义的情况下则不然。在此映射中存储用户定义类型数据时,我收到以下错误:-
**ERROR [WebExceptionHandler] Error occurred while serving request. Response is as [Response(
description=Type definition error: [simple type, class com.yyz.util.Abc];
nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException:
No serializer found for class com.yyz.util.Abc
and no properties discovered to create BeanSerializer
(to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)
(through reference chain: com.xyz.api.web.model.BuResponse["rows"]->java.util.ArrayList[0]->com.xyz.api.web.model.BuRow["children"]->java.util.ArrayList[11]->com.com.xyz.api.web.model.BuRow["[anySetter]"]->java.util.HashMap["column6"]), executionTime=0, responseEntity=<204 No Content,{}>,** responseStatus=ResponseStatus(hasError=true, responseKey=process-exception))]
org.springframework.http.converter.HttpMessageConversionException: Type definition error: [simple type, class com.yyz.util.Abc]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class …Run Code Online (Sandbox Code Playgroud) 为什么,如果我的类有一个org字段,我不能使用@Slf4jLombok 日志注释。以下代码将在第 #3 行产生编译错误:
MyClass.java:[3,1] 无法从静态上下文引用非静态变量 org
import lombok.extern.slf4j.Slf4j;
@Slf4j
class MyClass {
String org;
void printDebug() { log.debug("Org: " + org); }
}
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Lombok 文档 ( projectlombok.org/features/log ) 声称它添加了一个log字段。为什么它与 冲突org?