Class PropertiesConfigurationLayout
- java.lang.Object
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- org.apache.commons.configuration2.PropertiesConfigurationLayout
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- All Implemented Interfaces:
EventListener<ConfigurationEvent>
public class PropertiesConfigurationLayout extends java.lang.Object implements EventListener<ConfigurationEvent>
A helper class used by
PropertiesConfiguration
to keep the layout of a properties file.Instances of this class are associated with a
PropertiesConfiguration
object. They are responsible for analyzing properties files and for extracting as much information about the file layout (e.g. empty lines, comments) as possible. When the properties file is written back again it should be close to the original.The
PropertiesConfigurationLayout
object associated with aPropertiesConfiguration
object can be obtained using thegetLayout()
method of the configuration. Then the methods provided by this class can be used to alter the properties file's layout.Implementation note: This is a very simple implementation, which is far away from being perfect, i.e. the original layout of a properties file won't be reproduced in all cases. One limitation is that comments for multi-valued property keys are concatenated. Maybe this implementation can later be improved.
To get an impression how this class works consider the following properties file:
# A demo configuration file # for Demo App 1.42 # Application name AppName=Demo App # Application vendor AppVendor=DemoSoft # GUI properties # Window Color windowColors=0xFFFFFF,0x000000 # Include some setting include=settings.properties # Another vendor AppVendor=TestSoft
For this example the following points are relevant:
- The first two lines are set as header comment. The header comment is determined by the last blanc line before the first property definition.
- For the property
AppName
one comment line and one leading blanc line is stored. - For the property
windowColors
two comment lines and two leading blanc lines are stored. - Include files is something this class cannot deal with well. When saving the properties configuration back, the included properties are simply contained in the original file. The comment before the include property is skipped.
- For all properties except for
AppVendor
the "single line" flag is set. This is relevant only forwindowColors
, which has multiple values defined in one line using the separator character. - The
AppVendor
property appears twice. The comment lines are concatenated, so thatlayout.getComment("AppVendor");
will result inApplication vendor<CR>Another vendor
, with<CR>
meaning the line separator. In addition the "single line" flag is set to false for this property. When the file is saved, two property definitions will be written (in series).
- Since:
- 1.3
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Constructor Summary
Constructors Constructor Description PropertiesConfigurationLayout()
Creates a new, empty instance ofPropertiesConfigurationLayout
.PropertiesConfigurationLayout(PropertiesConfigurationLayout c)
Creates a new instance ofPropertiesConfigurationLayout
and copies the data of the specified layout object.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description int
getBlancLinesBefore(java.lang.String key)
Returns the number of blanc lines before this property key.java.lang.String
getCanonicalComment(java.lang.String key, boolean commentChar)
Returns the comment for the specified property key in a canonical form.java.lang.String
getCanonicalFooterCooment(boolean commentChar)
Returns the footer comment of the represented properties file in a canonical form.java.lang.String
getCanonicalHeaderComment(boolean commentChar)
Returns the header comment of the represented properties file in a canonical form.java.lang.String
getComment(java.lang.String key)
Returns the comment for the specified property key.java.lang.String
getFooterComment()
Returns the footer comment of the represented properties file.java.lang.String
getGlobalSeparator()
Returns the global separator.java.lang.String
getHeaderComment()
Returns the header comment of the represented properties file.java.util.Set<java.lang.String>
getKeys()
Returns a set with all property keys managed by this object.java.lang.String
getLineSeparator()
Returns the line separator.java.lang.String
getSeparator(java.lang.String key)
Returns the separator for the property with the given key.boolean
isForceSingleLine()
Returns the "force single line" flag.boolean
isSingleLine(java.lang.String key)
Returns a flag whether the specified property is defined on a single line.void
load(PropertiesConfiguration config, java.io.Reader in)
Reads a properties file and stores its internal structure.void
onEvent(ConfigurationEvent event)
The event listener callback.void
save(PropertiesConfiguration config, java.io.Writer out)
Writes the properties file to the given writer, preserving as much of its structure as possible.void
setBlancLinesBefore(java.lang.String key, int number)
Sets the number of blanc lines before the given property key.void
setComment(java.lang.String key, java.lang.String comment)
Sets the comment for the specified property key.void
setFooterComment(java.lang.String footerComment)
Sets the footer comment for the represented properties file.void
setForceSingleLine(boolean f)
Sets the "force single line" flag.void
setGlobalSeparator(java.lang.String globalSeparator)
Sets the global separator for properties.void
setHeaderComment(java.lang.String comment)
Sets the header comment for the represented properties file.void
setLineSeparator(java.lang.String lineSeparator)
Sets the line separator.void
setSeparator(java.lang.String key, java.lang.String sep)
Sets the separator to be used for the property with the given key.void
setSingleLine(java.lang.String key, boolean f)
Sets the "single line flag" for the specified property key.
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Constructor Detail
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PropertiesConfigurationLayout
public PropertiesConfigurationLayout()
Creates a new, empty instance ofPropertiesConfigurationLayout
.
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PropertiesConfigurationLayout
public PropertiesConfigurationLayout(PropertiesConfigurationLayout c)
Creates a new instance ofPropertiesConfigurationLayout
and copies the data of the specified layout object.- Parameters:
c
- the layout object to be copied
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Method Detail
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getCanonicalComment
public java.lang.String getCanonicalComment(java.lang.String key, boolean commentChar)
Returns the comment for the specified property key in a canonical form. "Canonical" means that either all lines start with a comment character or none. If thecommentChar
parameter is false, all comment characters are removed, so that the result is only the plain text of the comment. Otherwise it is ensured that each line of the comment starts with a comment character. Also, line breaks in the comment are normalized to the line separator "\n".- Parameters:
key
- the key of the propertycommentChar
- determines whether all lines should start with comment characters or not- Returns:
- the canonical comment for this key (can be null)
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getComment
public java.lang.String getComment(java.lang.String key)
Returns the comment for the specified property key. The comment is returned as it was set (either manually by callingsetComment()
or when it was loaded from a properties file). No modifications are performed.- Parameters:
key
- the key of the property- Returns:
- the comment for this key (can be null)
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setComment
public void setComment(java.lang.String key, java.lang.String comment)
Sets the comment for the specified property key. The comment (or its single lines if it is a multi-line comment) can start with a comment character. If this is the case, it will be written without changes. Otherwise a default comment character is added automatically.- Parameters:
key
- the key of the propertycomment
- the comment for this key (can be null, then the comment will be removed)
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getBlancLinesBefore
public int getBlancLinesBefore(java.lang.String key)
Returns the number of blanc lines before this property key. If this key does not exist, 0 will be returned.- Parameters:
key
- the property key- Returns:
- the number of blanc lines before the property definition for this key
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setBlancLinesBefore
public void setBlancLinesBefore(java.lang.String key, int number)
Sets the number of blanc lines before the given property key. This can be used for a logical grouping of properties.- Parameters:
key
- the property keynumber
- the number of blanc lines to add before this property definition
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getCanonicalHeaderComment
public java.lang.String getCanonicalHeaderComment(boolean commentChar)
Returns the header comment of the represented properties file in a canonical form. With thecommentChar
parameter it can be specified whether comment characters should be stripped or be always present.- Parameters:
commentChar
- determines the presence of comment characters- Returns:
- the header comment (can be null)
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getHeaderComment
public java.lang.String getHeaderComment()
Returns the header comment of the represented properties file. This method returns the header comment exactly as it was set usingsetHeaderComment()
or extracted from the loaded properties file.- Returns:
- the header comment (can be null)
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setHeaderComment
public void setHeaderComment(java.lang.String comment)
Sets the header comment for the represented properties file. This comment will be output on top of the file.- Parameters:
comment
- the comment
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getCanonicalFooterCooment
public java.lang.String getCanonicalFooterCooment(boolean commentChar)
Returns the footer comment of the represented properties file in a canonical form. This method works likegetCanonicalHeaderComment()
, but reads the footer comment.- Parameters:
commentChar
- determines the presence of comment characters- Returns:
- the footer comment (can be null)
- Since:
- 2.0
- See Also:
getCanonicalHeaderComment(boolean)
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getFooterComment
public java.lang.String getFooterComment()
Returns the footer comment of the represented properties file. This method returns the footer comment exactly as it was set usingsetFooterComment()
or extracted from the loaded properties file.- Returns:
- the footer comment (can be null)
- Since:
- 2.0
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setFooterComment
public void setFooterComment(java.lang.String footerComment)
Sets the footer comment for the represented properties file. This comment will be output at the bottom of the file.- Parameters:
footerComment
- the footer comment- Since:
- 2.0
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isSingleLine
public boolean isSingleLine(java.lang.String key)
Returns a flag whether the specified property is defined on a single line. This is meaningful only if this property has multiple values.- Parameters:
key
- the property key- Returns:
- a flag if this property is defined on a single line
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setSingleLine
public void setSingleLine(java.lang.String key, boolean f)
Sets the "single line flag" for the specified property key. This flag is evaluated if the property has multiple values (i.e. if it is a list property). In this case, if the flag is set, all values will be written in a single property definition using the list delimiter as separator. Otherwise multiple lines will be written for this property, each line containing one property value.- Parameters:
key
- the property keyf
- the single line flag
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isForceSingleLine
public boolean isForceSingleLine()
Returns the "force single line" flag.- Returns:
- the force single line flag
- See Also:
setForceSingleLine(boolean)
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setForceSingleLine
public void setForceSingleLine(boolean f)
Sets the "force single line" flag. If this flag is set, all properties with multiple values are written on single lines. This mode provides more compatibility withjava.lang.Properties
, which cannot deal with multiple definitions of a single property. This mode has no effect if the list delimiter parsing is disabled.- Parameters:
f
- the force single line flag
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getSeparator
public java.lang.String getSeparator(java.lang.String key)
Returns the separator for the property with the given key.- Parameters:
key
- the property key- Returns:
- the property separator for this property
- Since:
- 1.7
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setSeparator
public void setSeparator(java.lang.String key, java.lang.String sep)
Sets the separator to be used for the property with the given key. The separator is the string between the property key and its value. For new properties " = " is used. When a properties file is read, the layout tries to determine the separator for each property. With this method the separator can be changed. To be compatible with the properties format only the characters=
and:
(with or without whitespace) should be used, but this method does not enforce this - it accepts arbitrary strings. If the key refers to a property with multiple values that are written on multiple lines, this separator will be used on all lines.- Parameters:
key
- the key for the propertysep
- the separator to be used for this property- Since:
- 1.7
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getGlobalSeparator
public java.lang.String getGlobalSeparator()
Returns the global separator.- Returns:
- the global properties separator
- Since:
- 1.7
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setGlobalSeparator
public void setGlobalSeparator(java.lang.String globalSeparator)
Sets the global separator for properties. With this method a separator can be set that will be used for all properties when writing the configuration. This is an easy way of determining the properties separator globally. To be compatible with the properties format only the characters=
and:
(with or without whitespace) should be used, but this method does not enforce this - it accepts arbitrary strings. If the global separator is set to null, property separators are not changed. This is the default behavior as it produces results that are closer to the original properties file.- Parameters:
globalSeparator
- the separator to be used for all properties- Since:
- 1.7
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getLineSeparator
public java.lang.String getLineSeparator()
Returns the line separator.- Returns:
- the line separator
- Since:
- 1.7
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setLineSeparator
public void setLineSeparator(java.lang.String lineSeparator)
Sets the line separator. When writing the properties configuration, all lines are terminated with this separator. If no separator was set, the platform-specific default line separator is used.- Parameters:
lineSeparator
- the line separator- Since:
- 1.7
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getKeys
public java.util.Set<java.lang.String> getKeys()
Returns a set with all property keys managed by this object.- Returns:
- a set with all contained property keys
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load
public void load(PropertiesConfiguration config, java.io.Reader in) throws ConfigurationException
Reads a properties file and stores its internal structure. The found properties will be added to the specified configuration object.- Parameters:
config
- the associated configuration objectin
- the reader to the properties file- Throws:
ConfigurationException
- if an error occurs
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save
public void save(PropertiesConfiguration config, java.io.Writer out) throws ConfigurationException
Writes the properties file to the given writer, preserving as much of its structure as possible.- Parameters:
config
- the associated configuration objectout
- the writer- Throws:
ConfigurationException
- if an error occurs
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onEvent
public void onEvent(ConfigurationEvent event)
The event listener callback. Here event notifications of the configuration object are processed to update the layout object properly.- Specified by:
onEvent
in interfaceEventListener<ConfigurationEvent>
- Parameters:
event
- the event object
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