NumberConverter (Java EE 5 SDK)

javax.faces.convert Class NumberConverter

java.lang.Object
  javax.faces.convert.NumberConverter

所有已实现的接口:

StateHolder, Converter

public class NumberConverter

extends Object

implements Converter, StateHolder

Converter implementation for java.lang.Number values.

The getAsObject() method parses a String into an java.lang.Double or java.lang.Long, according to the following algorithm:

• If the specified String is null, return a null. Otherwise, trim leading and trailing whitespace before proceeding.
• If the specified String - after trimming - has a zero length, return null.
• If the locale property is not null, use that Locale for managing parsing. Otherwise, use the Locale from the UIViewRoot.
• If a pattern has been specified, its syntax must conform the rules specified by java.text.DecimalFormat. Such a pattern will be used to parse, and the type property will be ignored.
• If a pattern has not been specified, parsing will be based on the type property, which expects a currency, a number, or a percent. The parse pattern for currencies, numbers, and percentages is determined by calling the getCurrencyInstance(), getNumberInstance(), or getPercentInstance() method of the java.text.NumberFormat class, passing in the selected Locale.
• If the integerOnly property has been set to true, only the integer portion of the String will be parsed. See the JavaDocs for the setParseIntegerOnly() method of the java.text.NumberFormat class for more information.

The getAsString() method expects a value of type java.lang.Number (or a subclass), and creates a formatted String according to the following algorithm:

• If the specified value is null, return a zero-length String.
• If the specified value is a String, return it unmodified.
• If the locale property is not null, use that Locale for managing formatting. Otherwise, use the Locale from the FacesContext.
• If a pattern has been specified, its syntax must conform the rules specified by java.text.DecimalFormat. Such a pattern will be used to format, and the type property (along with related formatting options described in the next paragraph) will be ignored.
• If a pattern has not been specified, formatting will be based on the type property, which formats the value as a currency, a number, or a percent. The format pattern for currencies, numbers, and percentages is determined by calling the percentages is determined by calling the getCurrencyInstance(), getNumberInstance(), or getPercentInstance() method of the java.text.NumberFormat class, passing in the selected Locale. In addition, the following properties will be applied to the format pattern, if specified:
  • If the groupingUsed property is true, the setGroupingUsed(true) method on the corresponding NumberFormat instance will be called.
  • The minimum and maximum number of digits in the integer and fractional portions of the result will be configured based on any values set for the maxFractionDigits, maxIntegerDigits, minFractionDigits, and minIntegerDigits properties.
  • If the type is set to currency, it is also possible to configure the currency symbol to be used, using either the currencyCode or currencySymbol properties. If both are set, the value for currencyCode takes precedence on a JDK 1.4 (or later) JVM; otherwise, the value for currencySymbol takes precedence.

CONVERTER_ID

public static final String CONVERTER_ID

The standard converter id for this converter.

另请参见:

常量字段

CURRENCY_ID

public static final String CURRENCY_ID

The message identifier of the FacesMessage to be created if the conversion to Number fails. The message format string for this message may optionally include the following placeholders:

• {0} replaced by the unconverted value.
• {1} replaced by an example value.
• {2} replaced by a String whose value is the label of the input component that produced this message.

另请参见:

常量字段

NUMBER_ID

public static final String NUMBER_ID

The message identifier of the FacesMessage to be created if the conversion to Number fails. The message format string for this message may optionally include the following placeholders:

• {0} replaced by the unconverted value.
• {1} replaced by an example value.
• {2} replaced by a String whose value is the label of the input component that produced this message.

另请参见:

常量字段

PATTERN_ID

public static final String PATTERN_ID

The message identifier of the FacesMessage to be created if the conversion to Number fails. The message format string for this message may optionally include the following placeholders:

• {0} replaced by the unconverted value.
• {1} replaced by an example value.
• {2} replaced by a String whose value is the label of the input component that produced this message.

另请参见:

常量字段

PERCENT_ID

public static final String PERCENT_ID

The message identifier of the FacesMessage to be created if the conversion to Number fails. The message format string for this message may optionally include the following placeholders:

• {0} replaced by the unconverted value.
• {1} replaced by an example value.
• {2} replaced by a String whose value is the label of the input component that produced this message.

另请参见:

常量字段

STRING_ID

public static final String STRING_ID

The message identifier of the FacesMessage to be created if the conversion of the Number value to String fails. The message format string for this message may optionally include the following placeholders:

• {0} relaced by the unconverted value.
• {1} replaced by a String whose value is the label of the input component that produced this message.

另请参见:

常量字段

NumberConverter

public NumberConverter()

getCurrencyCode

public String getCurrencyCode()

Return the ISO 4217 currency code used by getAsString() with a type of currency. If not set, the value used will be based on the formatting Locale.

setCurrencyCode

public void setCurrencyCode(String currencyCode)

Set the ISO 4217 currency code used by getAsString() with a type of currency.

参数:

currencyCode - The new currency code

getCurrencySymbol

public String getCurrencySymbol()

Return the currency symbol used by getAsString() with a type of currency. If not set, the value used will be based on the formatting Locale.

setCurrencySymbol

public void setCurrencySymbol(String currencySymbol)

Set the currency symbol used by getAsString() with a type of currency.

参数:

currencySymbol - The new currency symbol

isGroupingUsed

public boolean isGroupingUsed()

Return true if getAsString should include grouping separators if necessary. If not modified, the default value is true.

setGroupingUsed

public void setGroupingUsed(boolean groupingUsed)

Set the flag indicating whether getAsString() should include grouping separators if necessary.

参数:

groupingUsed - The new grouping used flag

isIntegerOnly

public boolean isIntegerOnly()

Return true if only the integer portion of the given value should be returned from getAsObject(). If not modified, the default value is false.

setIntegerOnly

public void setIntegerOnly(boolean integerOnly)

Set to true if only the integer portion of the given value should be returned from getAsObject().

参数:

integerOnly - The new integer-only flag

getMaxFractionDigits

public int getMaxFractionDigits()

Return the maximum number of digits getAsString() should render in the fraction portion of the result.

setMaxFractionDigits

public void setMaxFractionDigits(int maxFractionDigits)

Set the maximum number of digits getAsString() should render in the fraction portion of the result. If not set, the number of digits depends on the value being converted.

参数:

maxFractionDigits - The new limit

getMaxIntegerDigits

public int getMaxIntegerDigits()

Return the maximum number of digits getAsString() should render in the integer portion of the result.

setMaxIntegerDigits

public void setMaxIntegerDigits(int maxIntegerDigits)

Set the maximum number of digits getAsString() should render in the integer portion of the result. If not set, the number of digits depends on the value being converted.

参数:

maxIntegerDigits - The new limit

getMinFractionDigits

public int getMinFractionDigits()

Return the minimum number of digits getAsString() should render in the fraction portion of the result.

setMinFractionDigits

public void setMinFractionDigits(int minFractionDigits)

Set the minimum number of digits getAsString() should render in the fraction portion of the result. If not set, the number of digits depends on the value being converted.

参数:

minFractionDigits - The new limit

getMinIntegerDigits

public int getMinIntegerDigits()

Return the minimum number of digits getAsString() should render in the integer portion of the result.

setMinIntegerDigits

public void setMinIntegerDigits(int minIntegerDigits)

Set the minimum number of digits getAsString() should render in the integer portion of the result. If not set, the number of digits depends on the value being converted.

参数:

minIntegerDigits - The new limit

getLocale

public Locale getLocale()

Return the Locale to be used when parsing numbers. If this value is null, the Locale stored in the UIViewRoot for the current request will be utilized.

setLocale

public void setLocale(Locale locale)

Set the Locale to be used when parsing numbers. If set to null, the Locale stored in the UIViewRoot for the current request will be utilized.

参数:

locale - The new Locale (or null)

getPattern

public String getPattern()

Return the format pattern to be used when formatting and parsing numbers.

setPattern

public void setPattern(String pattern)

Set the format pattern to be used when formatting and parsing numbers. Valid values are those supported by java.text.DecimalFormat. An invalid value will cause a ConverterException when getAsObject() or getAsString() is called.

参数:

pattern - The new format pattern

getType

public String getType()

Return the number type to be used when formatting and parsing numbers. If not modified, the default type is number.

setType

public void setType(String type)

Set the number type to be used when formatting and parsing numbers. Valid values are currency, number, or percent. An invalid value will cause a ConverterException when getAsObject() or getAsString() is called.

参数:

type - The new number style

getAsObject

public Object getAsObject(FacesContext context,
                          UIComponent component,
                          String value)

Description copied from interface: Converter

Convert the specified string value, which is associated with the specified UIComponent, into a model data object that is appropriate for being stored during the Apply Request Values phase of the request processing lifecycle.

规范说明:

getAsObject in interface Converter

参数:

context - FacesContext for the request being processed

component - UIComponent with which this model object value is associated

value - String value to be converted (may be null)

返回:

null if the value to convert is null, otherwise the result of the conversion

抛出异常:

ConverterException - if conversion cannot be successfully performed

NullPointerException - if context or component is null

getAsString

public String getAsString(FacesContext context,
                          UIComponent component,
                          Object value)

Description copied from interface: Converter

Convert the specified model object value, which is associated with the specified UIComponent, into a String that is suitable for being included in the response generated during the Render Response phase of the request processing lifeycle.

规范说明:

getAsString in interface Converter

参数:

context - FacesContext for the request being processed

component - UIComponent with which this model object value is associated

value - Model object value to be converted (may be null)

返回:

a zero-length String if value is null, otherwise the result of the conversion

抛出异常:

ConverterException - if conversion cannot be successfully performed

NullPointerException - if context or component is null

saveState

public Object saveState(FacesContext context)

Description copied from interface: StateHolder

Gets the state of the instance as a Serializable Object.

If the class that implements this interface has references to instances that implement StateHolder (such as a UIComponent with event handlers, validators, etc.) this method must call the StateHolder.saveState(javax.faces.context.FacesContext) method on all those instances as well. This method must not save the state of children and facets. That is done via the StateManager

This method must not alter the state of the implementing object. In other words, after executing this code:

 Object state = component.saveState(facesContext);
 

component should be the same as before executing it.

The return from this method must be Serializable

规范说明:

saveState in interface StateHolder

public void restoreState(FacesContext context,
                         Object state)

public boolean isTransient()

public void setTransient(boolean transientFlag)