小编Twe*_*eak的帖子

我的实体有一个像

@Column(name = "workflow_status", columnDefinition = "nvarchar(255)")
private String workflow_status;

所以在我的控制器中，我想通过 获取条目workflow_status，我编写了 JPA 提供的查询方法

List<Programme> findByWorkflow_status(String workflow_status);

但这给出了错误

Caused by: java.lang.IllegalArgumentException: Failed to create query method public abstract java.util.List com.taap.backend.programmes.repositories.ProgRepo.findByWorkflow_status(java.lang.String)! No property workflow found for type Programme!
at org.springframework.data.jpa.repository.query.PartTreeJpaQuery.<init>(PartTreeJpaQuery.java:76) ~[spring-data-jpa-1.11.9.RELEASE.jar:na]
at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:101) ~[spring-data-jpa-1.11.9.RELEASE.jar:na]
at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$CreateIfNotFoundQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:207) ~[spring-data-jpa-1.11.9.RELEASE.jar:na]
at org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy$AbstractQueryLookupStrategy.resolveQuery(JpaQueryLookupStrategy.java:77) ~[spring-data-jpa-1.11.9.RELEASE.jar:na]
at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.<init>(RepositoryFactorySupport.java:451) ~[spring-data-commons-1.13.9.RELEASE.jar:na]
at org.springframework.data.repository.core.support.RepositoryFactorySupport.getRepository(RepositoryFactorySupport.java:224) ~[spring-data-commons-1.13.9.RELEASE.jar:na]
at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.initAndReturn(RepositoryFactoryBeanSupport.java:277) ~[spring-data-commons-1.13.9.RELEASE.jar:na]
at org.springframework.data.repository.core.support.RepositoryFactoryBeanSupport.afterPropertiesSet(RepositoryFactoryBeanSupport.java:263) ~[spring-data-commons-1.13.9.RELEASE.jar:na]
at org.springframework.data.jpa.repository.support.JpaRepositoryFactoryBean.afterPropertiesSet(JpaRepositoryFactoryBean.java:101) ~[spring-data-jpa-1.11.9.RELEASE.jar:na]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1687) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1624) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
... 48 common frames omitted
Caused by: org.springframework.data.mapping.PropertyReferenceException: …

我正在尝试将String转换为char数组,以便我可以在其中搜索char:

char[] arr = new char[str.length()];
for (i = 0; i < str.length(); i++) {
    arr[i] = str.charAt(i);
}
do {
    //   Something
} while (arr[i] != " ");

但最后一行在Eclipse中出现此错误:

不兼容的操作数类型Char和String

即使我使用方法toCharArray,错误仍然存​​在.谁能解释一下为什么？