Class ErrorHandler

java.lang.Object

org.eclipse.jetty.server.handler.ErrorHandler

All Implemented Interfaces:

Request.Handler, Invocable

Direct Known Subclasses:

ErrorHandler, ErrorHandler, ReHandlingErrorHandler

@ManagedObject
public class ErrorHandler
extends Object
implements Request.Handler

Handler for Error pages An ErrorHandler is registered with Server.setErrorHandler(Request.Handler). It is called by the Response.writeError(Request, Response, Callback, int, String) to generate an error page.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ErrorHandler.ErrorRequest

Nested classes/interfaces inherited from interface org.eclipse.jetty.util.thread.Invocable

Invocable.Callable, Invocable.InvocationType, Invocable.ReadyTask, Invocable.Task

Nested classes/interfaces inherited from interface org.eclipse.jetty.server.Request.Handler

Request.Handler.AbortException

Field Summary

Fields

Modifier and Type	Field	Description
static final HttpField	ERROR_CACHE_CONTROL
static final String	ERROR_CONTEXT
static final String	ERROR_EXCEPTION
static final String	ERROR_MESSAGE
static final Set<String>	ERROR_METHODS
static final String	ERROR_ORIGIN
static final String	ERROR_STATUS

Fields inherited from interface org.eclipse.jetty.util.thread.Invocable

__nonBlocking, NOOP

Constructor Summary

Constructors

Constructor	Description
ErrorHandler()

Method Summary

Modifier and Type	Method	Description
ByteBuffer	badMessageError(int status, String reason, HttpFields.Mutable fields)	Deprecated, for removal: This API element is subject to removal in a future version. Do not override.
protected int	computeBufferSize(Request request)
boolean	errorPageForMethod(String method)
protected boolean	generateAcceptableResponse(Request request, Response response, Callback callback, String contentType, List<Charset> charsets, int code, String message, Throwable cause)
protected void	generateCacheControl(Response response)
protected void	generateResponse(Request request, Response response, int code, String message, Throwable cause, Callback callback)
int	getBufferSize()
String	getCacheControl()	Get the cacheControl.
String	getDefaultResponseMimeType()
static Request.Handler	getErrorHandler(Server server, ContextHandler context)
boolean	handle(Request request, Response response, Callback callback)	Invoked to handle the passed HTTP request and response.
protected void	htmlRow(Writer writer, String tag, Object value)
boolean	isShowCauses()
boolean	isShowMessageInTitle()
boolean	isShowOrigin()
boolean	isShowStacks()
void	setBufferSize(int bufferSize)
void	setCacheControl(String cacheControl)	Set the cacheControl.
void	setDefaultResponseMimeType(String defaultResponseMimeType)
void	setShowCauses(boolean showCauses)
void	setShowMessageInTitle(boolean showMessageInTitle)	Set if true, the error message appears in page title.
void	setShowOrigin(boolean showOrigin)
void	setShowStacks(boolean showStacks)
String	toString()
protected void	write(Writer writer, String string)
boolean	writeError(Request request, Response response, Callback callback, int code)	Write an error response, or signal that the error will be handled by a down stream handler.
protected void	writeErrorHtml(Request request, Writer writer, Charset charset, int code, String message, Throwable cause)
protected void	writeErrorHtmlBody(Request request, Writer writer, int code, String message, Throwable cause)
protected void	writeErrorHtmlHead(Request request, Writer writer, int code, String message)
protected void	writeErrorHtmlMessage(Request request, Writer writer, int code, String message, Throwable cause, String uri)
protected void	writeErrorHtmlMeta(Request request, Writer writer, Charset charset)
protected void	writeErrorHtmlStacks(Request request, Writer writer)
protected void	writeErrorJson(Request request, PrintWriter writer, int code, String message, Throwable cause)
protected void	writeErrorOrigin(String origin, Consumer<String> consumer)
protected void	writeErrorPlain(Request request, PrintWriter writer, int code, String message, Throwable cause)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.eclipse.jetty.server.Request.Handler

getInvocationType

Field Details

ERROR_STATUS

public static final String ERROR_STATUS

See Also:

• Constant Field Values

ERROR_MESSAGE

public static final String ERROR_MESSAGE

See Also:

• Constant Field Values

ERROR_EXCEPTION

public static final String ERROR_EXCEPTION

See Also:

• Constant Field Values

ERROR_CONTEXT

public static final String ERROR_CONTEXT

See Also:

• Constant Field Values

ERROR_ORIGIN

public static final String ERROR_ORIGIN

See Also:

• Constant Field Values

ERROR_METHODS

public static final Set<String> ERROR_METHODS

ERROR_CACHE_CONTROL

public static final HttpField ERROR_CACHE_CONTROL

Constructor Details

ErrorHandler

public ErrorHandler()

Method Details

errorPageForMethod

public boolean errorPageForMethod(String method)

writeError

public boolean writeError(Request request,
 Response response,
 Callback callback,
 int code)

Write an error response, or signal that the error will be handled by a down stream handler.

The default implementation calls Response.writeError(Request, Response, Callback, int) and returns true.

ErrorHandler extensions may override this method to modify the state of the Request and/or Response so that when the method returns false an error page will be generated by a subsequent Handler. For example, Servlet implementations override this method to set attributes that trigger a Servlet `sendError` call when the ServletHandler invokes the ServletChannel.

Parameters:

request - The request.

response - The response.

callback - The callback to call when the response is written.

code - The error status code.

Returns:

true if the error response was written; false if the state of the request and/or response has been changed so that by continuing normal handling an error response will be generated by a down stream handler.

handle

public boolean handle(Request request,
 Response response,
 Callback callback)
               throws Exception

Description copied from interface: Request.Handler

Invoked to handle the passed HTTP request and response.

The request is accepted by returning true, then handling must be concluded by completing the passed callback. The handling may be asynchronous, i.e. this method may return true and complete the given callback later, possibly from a different thread. If this method returns false, then the callback must not be invoked and any mutation on the response reversed.

Exceptions thrown by this method may be subsequently handled by an error Request.Handler, if present, otherwise a default HTTP 500 error is generated and the callback completed while writing the error response.

The simplest implementation is:

 public boolean handle(Request request, Response response, Callback callback)
 {
     callback.succeeded();
     return true;
 }
 

A HelloWorld implementation is:

 public boolean handle(Request request, Response response, Callback callback)
 {
     response.write(true, ByteBuffer.wrap("Hello World\n".getBytes(StandardCharsets.UTF_8)), callback);
     return true;
 }
 

Specified by:

handle in interface Request.Handler

Parameters:

request - the HTTP request to handle

response - the HTTP response to handle

callback - the callback to complete when the handling is complete

Returns:

True if and only if the request will be handled, a response generated and the callback eventually called. This may occur within the scope of the call to this method, or asynchronously some time later. If false is returned, then this method must not generate a response, nor complete the callback.

Throws:

Exception - if there is a failure during the handling. Catchers cannot assume that the callback will be called and thus should attempt to complete the request as if a false had been returned.

See Also:

• Request.Handler.AbortException

generateCacheControl

protected void generateCacheControl(Response response)

generateResponse

protected void generateResponse(Request request,
 Response response,
 int code,
 String message,
 Throwable cause,
 Callback callback)
                         throws IOException

Throws:

IOException

generateAcceptableResponse

protected boolean generateAcceptableResponse(Request request,
 Response response,
 Callback callback,
 String contentType,
 List<Charset> charsets,
 int code,
 String message,
 Throwable cause)
                                      throws IOException

Throws:

IOException

computeBufferSize

protected int computeBufferSize(Request request)

writeErrorHtml

protected void writeErrorHtml(Request request,
 Writer writer,
 Charset charset,
 int code,
 String message,
 Throwable cause)
                       throws IOException

Throws:

IOException

writeErrorHtmlMeta

protected void writeErrorHtmlMeta(Request request,
 Writer writer,
 Charset charset)
                           throws IOException

Throws:

IOException

writeErrorHtmlHead

protected void writeErrorHtmlHead(Request request,
 Writer writer,
 int code,
 String message)
                           throws IOException

Throws:

IOException

writeErrorHtmlBody

protected void writeErrorHtmlBody(Request request,
 Writer writer,
 int code,
 String message,
 Throwable cause)
                           throws IOException

Throws:

IOException

writeErrorHtmlMessage

protected void writeErrorHtmlMessage(Request request,
 Writer writer,
 int code,
 String message,
 Throwable cause,
 String uri)
                              throws IOException

Throws:

IOException

htmlRow

protected void htmlRow(Writer writer,
 String tag,
 Object value)
                throws IOException

Throws:

IOException

writeErrorPlain

protected void writeErrorPlain(Request request,
 PrintWriter writer,
 int code,
 String message,
 Throwable cause)

writeErrorOrigin

protected void writeErrorOrigin(String origin,
 Consumer<String> consumer)

writeErrorJson

protected void writeErrorJson(Request request,
 PrintWriter writer,
 int code,
 String message,
 Throwable cause)

writeErrorHtmlStacks

protected void writeErrorHtmlStacks(Request request,
 Writer writer)
                             throws IOException

Throws:

IOException

badMessageError

@Deprecated(since="12.0.8",
            forRemoval=true)
public ByteBuffer badMessageError(int status,
 String reason,
 HttpFields.Mutable fields)

Deprecated, for removal: This API element is subject to removal in a future version.

Do not override. No longer invoked by Jetty.

Bad Message Error body

Generate an error response body to be sent for a bad message. In this case there is something wrong with the request, so either a request cannot be built, or it is not safe to build a request. This method allows for a simple error page body to be returned and some response headers to be set.

Parameters:

status - The error code that will be sent

reason - The reason for the error code (may be null)

fields - The header fields that will be sent with the response.

Returns:

The content as a ByteBuffer, or null for no body.

getCacheControl

@ManagedAttribute("The value of the Cache-Control response header")
public String getCacheControl()

Get the cacheControl.

Returns:

the cacheControl header to set on error responses.

setCacheControl

public void setCacheControl(String cacheControl)

Set the cacheControl.

Parameters:

cacheControl - the cacheControl header to set on error responses.

isShowStacks

@ManagedAttribute("Whether the error page shows the stack trace")
public boolean isShowStacks()

Returns:

True if stack traces are shown in the error pages

setShowStacks

public void setShowStacks(boolean showStacks)

Parameters:

showStacks - True if stack traces are shown in the error pages

isShowCauses

@ManagedAttribute("Whether the error page shows the exception causes")
public boolean isShowCauses()

Returns:

True if exception causes are shown in the error pages

setShowCauses

public void setShowCauses(boolean showCauses)

Parameters:

showCauses - True if exception causes are shown in the error pages

isShowMessageInTitle

@ManagedAttribute("Whether the error message is shown in the error page title")
public boolean isShowMessageInTitle()

setShowMessageInTitle

public void setShowMessageInTitle(boolean showMessageInTitle)

Set if true, the error message appears in page title.

Parameters:

showMessageInTitle - if true, the error message appears in page title

isShowOrigin

public boolean isShowOrigin()

setShowOrigin

public void setShowOrigin(boolean showOrigin)

getDefaultResponseMimeType

@ManagedAttribute("Mime type to be used when a client does not specify an Accept header, or the request did not fully parse")
public String getDefaultResponseMimeType()

Returns:

The mime type to be used when a client does not specify an Accept header, or the request did not fully parse

setDefaultResponseMimeType

public void setDefaultResponseMimeType(String defaultResponseMimeType)

Parameters:

defaultResponseMimeType - The mime type to be used when a client does not specify an Accept header, or the request did not fully parse

write

protected void write(Writer writer,
 String string)
              throws IOException

Throws:

IOException

getErrorHandler

public static Request.Handler getErrorHandler(Server server,
 ContextHandler context)

getBufferSize

@ManagedAttribute("Buffer size for entire error response")
public int getBufferSize()

Returns:

Buffer size for entire error response. If error page is bigger than buffer size, it will be truncated. With a -1 meaning that a heuristic will be used (e.g. min(8K, httpConfig.bufferSize))

setBufferSize

public void setBufferSize(int bufferSize)

Parameters:

bufferSize - Buffer size for entire error response. If error page is bigger than buffer size, it will be truncated. With a -1 meaning that a heuristic will be used (e.g. min(8K, httpConfig.bufferSize))

toString

public String toString()

Overrides:

toString in class Object