org.springframework.xd.dirt.stream.completion

Class StacktraceFingerprintingCompletionRecoveryStrategy<E extends java.lang.Exception>

java.lang.Object

org.springframework.xd.dirt.stream.completion.StacktraceFingerprintingCompletionRecoveryStrategy<E>

All Implemented Interfaces:

CompletionRecoveryStrategy<E>

Direct Known Subclasses:

EmptyStartYieldsModulesRecoveryStrategy, ExpandOneDashToTwoDashesRecoveryStrategy, ModulesAfterPipeRecoveryStrategy, OptionNameAfterDashDashRecoveryStrategy, UnfinishedModuleNameRecoveryStrategy, UnfinishedOptionNameRecoveryStrategy

public abstract class StacktraceFingerprintingCompletionRecoveryStrategy<E extends java.lang.Exception>
extends java.lang.Object
implements CompletionRecoveryStrategy<E>

A recovery strategy that will trigger if the parser failure is similar to that of some sample unfinished stream definition. The match is decided by analyzing the top frames of the stack trace emitted by the parser when it encounters the ill formed input. Multiple fingerprints are supported, as the control flow in the parser code may be different depending on the form of the expression. For example, for the rule stream = module (| module)* , the pseudo code for the parser may look like

 
 stream() {
   module();  (1)
   while(moreInput()) {
     swallowPipe();
     module();  (2)
   }
 }
 
 

In that setup, whether we're dealing with the first module, or a subsequent module, stack frames would be different (see (1) and (2)).

Author:

Eric Bottard, Gary Russell

Field Summary

Fields

Modifier and Type	Field and Description
protected XDParser	parser

Constructor Summary

Constructors

Constructor and Description
StacktraceFingerprintingCompletionRecoveryStrategy(XDParser parser, java.lang.Class<E> exceptionClass, java.lang.String... samples) Construct a new StacktraceFingerprintingCompletionRecoveryStrategy given the parser, and the expected exception class to be thrown for sample fragments of a stream definition that is to be parsed.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	shouldTrigger(java.lang.String dslStart, java.lang.Exception exception, CompletionKind kind) Whether this completion should be triggered.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.xd.dirt.stream.completion.CompletionRecoveryStrategy

addProposals

Field Detail

parser

protected final XDParser parser

Constructor Detail

StacktraceFingerprintingCompletionRecoveryStrategy

public StacktraceFingerprintingCompletionRecoveryStrategy(XDParser parser,
                                                  java.lang.Class<E> exceptionClass,
                                                  java.lang.String... samples)

Construct a new StacktraceFingerprintingCompletionRecoveryStrategy given the parser, and the expected exception class to be thrown for sample fragments of a stream definition that is to be parsed.

Parameters:

parser - the parser used to parse the sample fragment stream definitions.

exceptionClass - the expected exception that results from parsing the sample fragment stream definitions. Stack frames from the thrown exception are used to store the fingerprint of this exception thrown by the parser.

samples - the sample fragments of stream definitions.

Method Detail

shouldTrigger

public boolean shouldTrigger(java.lang.String dslStart,
                    java.lang.Exception exception,
                    CompletionKind kind)

Description copied from interface: CompletionRecoveryStrategy

Whether this completion should be triggered.

Specified by:

shouldTrigger in interface CompletionRecoveryStrategy<E extends java.lang.Exception>