com.goldencode.p2j.persist

Class FQLExpression

java.lang.Object

com.goldencode.p2j.persist.FQLExpression

public class FQLExpression
extends java.lang.Object

Represents an FQL expression: FQL where clause, FQL statement or FQL snippet. It allows to concatenate a string containing substitution parameters and then emit resulting string with proper placeholders, e.g. with placeholders for JPA-style positional parameters which have throughout numeration. Example of usage:

FQLExpression fql = new FQLExpression("where ");
fql.append("a = ", true);
fql.append(" and b");
fql.append(' = ", true);
fql.toFinalExpression; -> "where a = ?0 and b = ?1"

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	endsWithSubst true if the FQL expression ends with a substitution.
private boolean	hasLastPart Flag indicating if lastPart is used.
private java.lang.StringBuilder	lastPart String builder to speed up sequential concatenations.
private boolean	multiplexed By default, FQL expressions, including the empty ones are not (yet) multiplexed.
private java.util.List<java.lang.String>	parts Parts of the FQL expression separated by substitutions.

Constructor Summary

Constructors

Constructor and Description
FQLExpression() Create an empty FQL expression.
FQLExpression(FQLExpression starting) Create an FQL expression starting with the specified sub-expression.
FQLExpression(java.lang.String starting) Create an FQL expression starting with the specified sub-expression.
FQLExpression(java.lang.String starting, boolean endsWithSubst) Create an FQL expression starting with the specified sub-expression.

Method Summary

Modifier and Type	Method and Description
FQLExpression	append(FQLExpression subExpression) Append the expression with the specified sub-expression.
FQLExpression	append(java.lang.String subExpression) Append the expression with the specified sub-expression.
FQLExpression	append(java.lang.String subExpression, boolean endsWithSubst) Append the expression with the specified sub-expression.
boolean	isEmpty() If this expression is empty.
void	setMultiplexed(boolean multiplexed) Sets the expression's multiplexed property.
java.lang.String	toFinalExpression() Returns the final form of the FQL expression with placeholders emitted.
java.lang.String	toFinalExpression(boolean jpaStyle) Returns the final form of the FQL expression with placeholders emitted.
java.lang.String	toString() Returns the string representation of this expression.
FQLExpression	trim() Trim the expression.
boolean	wasMultiplexed() Test whether the multiplex check was added to this expression.
private void	writeLastPart() If the last part of the expression is contained in lastPart buffer, flush it to parts.

Methods inherited from class java.lang.Object

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

Field Detail

parts

private java.util.List<java.lang.String> parts

Parts of the FQL expression separated by substitutions.

endsWithSubst

private boolean endsWithSubst

true if the FQL expression ends with a substitution.

lastPart

private java.lang.StringBuilder lastPart

String builder to speed up sequential concatenations. Can be null or contain the last part for parts.

hasLastPart

private boolean hasLastPart

Flag indicating if lastPart is used.

multiplexed

private boolean multiplexed

By default, FQL expressions, including the empty ones are not (yet) multiplexed.

Constructor Detail

FQLExpression

public FQLExpression()

Create an empty FQL expression.

FQLExpression

public FQLExpression(FQLExpression starting)

Create an FQL expression starting with the specified sub-expression.

Parameters:

starting - Staring sub-expression.

FQLExpression

public FQLExpression(java.lang.String starting)

Create an FQL expression starting with the specified sub-expression.

Parameters:

starting - Staring sub-expression.

FQLExpression

public FQLExpression(java.lang.String starting,
                     boolean endsWithSubst)

Create an FQL expression starting with the specified sub-expression.

Parameters:

starting - Staring sub-expression.

endsWithSubst - true if the starting sub-expression ends with a substitution.

Method Detail

append

public FQLExpression append(java.lang.String subExpression)

Append the expression with the specified sub-expression.

Parameters:

subExpression - Sub-expression to append.

Returns:

this expression.

append

public FQLExpression append(java.lang.String subExpression,
                            boolean endsWithSubst)

Append the expression with the specified sub-expression.

Parameters:

subExpression - Sub-expression to append.

endsWithSubst - true if the appended sub-expression ends with a substitution.

Returns:

this expression.

append

public FQLExpression append(FQLExpression subExpression)

Append the expression with the specified sub-expression.

Parameters:

subExpression - Sub-expression to append.

Returns:

this expression.

toFinalExpression

public java.lang.String toFinalExpression()

Returns the final form of the FQL expression with placeholders emitted. Placeholders are for JPA-style positional parameters, i.e. ?0, ?1 etc.

Returns:

See above.

toFinalExpression

public java.lang.String toFinalExpression(boolean jpaStyle)

Returns the final form of the FQL expression with placeholders emitted. Placeholders are for JPA-style positional parameters, i.e. ?0, ?1 etc. if jpsStyle is true; otherwise, simple substitution placeholders (i.e., ?) are emitted.

Parameters:

jpaStyle - true to emit JPA-style positional parameter placeholders; false to emit simple placeholders.

Returns:

See above.

isEmpty

public boolean isEmpty()

If this expression is empty.

Returns:

true if this expression is empty.

trim

public FQLExpression trim()

Trim the expression.

Returns:

this expression.

toString

public java.lang.String toString()

Returns the string representation of this expression.

Overrides:

toString in class java.lang.Object

Returns:

the string representation of this expression.

writeLastPart

private void writeLastPart()

If the last part of the expression is contained in lastPart buffer, flush it to parts.

wasMultiplexed

public boolean wasMultiplexed()

Test whether the multiplex check was added to this expression.

Returns:

true if this expression was marked as multiplexed after the condition was added.

setMultiplexed

public void setMultiplexed(boolean multiplexed)

Sets the expression's multiplexed property. Normally, it makes sense to call this only with true parameter, after adding the multiplex check condition to expression. The opposite would be useful if the expression is cleared, but this feature is not currently available.

Parameters:

multiplexed - The new value of the property.