试图遵循这个Java教程.
大约63页,您被告知如何创建表单("New.jsp")来提交新事件.
当我尝试访问该页面时,出现以下错误:
HTTP Status 500 -
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Filter execution threw an exception
com.opensymphony.sitemesh.webapp.SiteMeshFilter.obtainContent(SiteMeshFilter.java:129)
com.opensymphony.sitemesh.webapp.SiteMeshFilter.doFilter(SiteMeshFilter.java:77)
org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
root cause
java.lang.NoClassDefFoundError: Could not initialize class freemarker.template.Configuration
org.apache.struts2.views.freemarker.FreemarkerManager.createConfiguration(FreemarkerManager.java:294)
org.apache.struts2.views.freemarker.FreemarkerManager.init(FreemarkerManager.java:255)
org.apache.struts2.views.freemarker.FreemarkerManager.getConfiguration(FreemarkerManager.java:238)
org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:734)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:506)
org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
com.opensymphony.sitemesh.webapp.SiteMeshFilter.obtainContent(SiteMeshFilter.java:129)
com.opensymphony.sitemesh.webapp.SiteMeshFilter.doFilter(SiteMeshFilter.java:77)
org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
note The full stack trace of the root cause is available in the Apache Tomcat/6.0.29 logs.
Apache Tomcat/6.0.29
我在D:\ education\java.metadata.plugins\org.eclipse.wst.server.core\tmp1\logs\localhost_access_log.2010-09-26.txt找到了这个日志
127.0.0.1 - …我目前正在开发一个 C# 解决方案，它将集成 Azure Key Vault。
如果互联网出现故障（我在柏林工作，所以并非完全不可能），或者如果我想在调试解决方案时排除网络连接问题，有没有办法设置本地实例？
我有以下方法：
[SuppressMessage("Reliability", "CA2000:Dispose objects before losing scope", Justification = "If we dispose of the csvWriter, it won't be available to write.")]
public static MemoryStream CreateCsvStream(IEnumerable<object> records)
{
MemoryStream memoryStream = new();
StreamWriter streamWriter = new(memoryStream);
CsvWriter csvWriter = new(streamWriter, CultureInfo.InvariantCulture);
csvWriter.Context.TypeConverterCache.AddConverter<bool>(new CollendaBooleanConverter());
csvWriter.Context.TypeConverterCache.AddConverter<bool?>(new CollendaBooleanConverter());
csvWriter.Context.TypeConverterCache.AddConverter<DateOnly>(new CollendaDateOnlyConverter());
csvWriter.Context.TypeConverterCache.AddConverter<DateOnly?>(new CollendaDateOnlyConverter());
csvWriter.Context.TypeConverterCache.AddConverter<decimal>(new CollendaDecimalConverter());
csvWriter.Context.TypeConverterCache.AddConverter<decimal?>(new CollendaDecimalConverter());
csvWriter.WriteRecords(records);
streamWriter.Flush();
return memoryStream;
}
这是可行的，但正如 中所暗示的SuppressMessage，如果我使用usingso MemoryStream、StreamWriter和/或CsvWriter，当我稍后执行以下代码时，它们将被释放：
private void Upload(MemoryStream memoryStream)
{
_sftpClient.Connect();
_ = memoryStream.Seek(0, SeekOrigin.Begin);
string …我有以下带有属性的C#类Id，我想使用 GUID 设置该属性，如果消费者调用尚未设置此值的 myClass.Id 实例的值，则返回该属性，否则保留并返回现有价值。
public class IdentifiableClass{
public string Id {
get {
if (this.Id == null) {
this.Id = Guid.NewGuid().ToString();
Console.WriteLine("########## Id : " + this.Id );
}
return this.Id;
}
set => this.Id = value;
}
}
在C＃中，这样做不是工作，而是我得到一个计算器（不是这个网站，很明显）。最好的猜测是，在同一属性的 getter 中调用 this.Id 似乎会导致循环逻辑。
在Salesforce Apex 中，使用类似的代码，它确实按照我的预期工作，将 this.Id 的值评估为 null，将值分配给新的 Guid，显示值，然后返回值：
public class IdentifiableClass {
public string Id {
get { …我有以下方法：
private async Task<(bool, string)> Relay(
WorkflowTask workflowTask,
MontageUploadConfig montageData,
File sourceFile,
CancellationToken cancellationToken
)
{
try
{
byte[] fileContent = await _httpClient.GetByteArrayAsync(sourceFile.Url, cancellationToken);
await _attachmentController.TryUploadAttachment(montageData.EventId, fileContent, sourceFile.Name);
return (true, null);
}
catch (Exception exception)
{
_logger.LogError(exception, $"File cannot be uploaded: {sourceFile.Name}", workflowTask);
return (false, exception.ToString());
}
}
我想重构它以使用TryAsyncfrom LanguageExt.Core（或其他一些功能Try类型）。
我已成功将上述方法重构为：
private TryAsync<bool> Relay(
MontageUploadConfig montageData,
File sourceFile,
CancellationToken cancellationToken
) => new(async () =>
{
byte[] fileContent = await _httpClient.GetByteArrayAsync(sourceFile.Url, cancellationToken);
return await _attachmentController.TryUploadAttachment(montageData.EventId, …我有一个枚举：
pub enum BoxColour {
Red,
Blue,
}
我不仅希望将此值作为 string 获取，而且还希望将该值转换为小写。
这有效：
impl Display for BoxColour {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
fmt.write_str(match self {
BoxColour::Red => "red",
BoxColour::Blue => "blue",
})?;
Ok(())
}
}
当颜色列表增加时，该列表需要更新。
如果我使用write!宏，似乎不可能操纵结果，因为write!返回一个实例()而不是一个String：
impl Display for BoxColour {
fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
write!(formatter, "{:?}", self)
}
}
这表明这是通过副作用起作用的，也许我们可以在内存中破解该值的相同位置，但即使这是可能的，也可能不是一个好主意......
我正在尝试在JSP中设置本地.
我以为我能做的事情如下:
<fmt:setLocale value="${param['local']}" scope="session"/>
关于这个主题的Java自己的页面似乎说得非常多.
但是,当我去执行它时,我得到:
HTTP Status 500 -
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: /pages/ResourceBundlesJSTL.jsp(11,0) According to TLD or attribute directive in tag file, attribute value does not accept any expressions
org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:40)
org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:407)
org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:148)
org.apache.jasper.compiler.Validator$ValidateVisitor.checkXmlAttributes(Validator.java:1232)
org.apache.jasper.compiler.Validator$ValidateVisitor.visit(Validator.java:868)
org.apache.jasper.compiler.Node$CustomTag.accept(Node.java:1539)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2376)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2428)
org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2434)
org.apache.jasper.compiler.Node$Root.accept(Node.java:475)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2376)
org.apache.jasper.compiler.Validator.validateExDirectives(Validator.java:1787)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:211)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:360)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:327)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:594)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:316)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
note The full stack trace of the root cause …