org.yarnandtail.andhow.load

Class BaseFixedValueLoader

java.lang.Object

org.yarnandtail.andhow.load.BaseLoader

org.yarnandtail.andhow.load.BaseFixedValueLoader

All Implemented Interfaces:

Loader, ReadLoader

Direct Known Subclasses:

StdFixedValueLoader

public abstract class BaseFixedValueLoader
extends BaseLoader
implements ReadLoader

Abstract loader that can load Property values from Property and value pairs.

Two types of Property-value pairs are supported: PropertyValue's (a direct reference to a Property and a typed value) and named properties (a Property canonical name or alias and a value for it).

To implement a non-abstract class, override the Loader.load(PropertyConfigurationInternal, LoaderEnvironment, ValidatedValuesWithContext) method with a call to load(PropertyConfigurationInternal, Map, List) and supply your own values for one or both of the two collections. For a simple example, see the StdFixedValueLoader.

By default, this loader does not trim incoming values for String type properties and will throw a RuntimeException if passed unrecognized properties. Both of these behaviours can be changed by modifying the return values of isTrimmingRequiredForStringValues() and isUnknownPropertyAProblem().

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	unknownPropertyAProblem

Constructor Summary

Constructors

Constructor and Description
BaseFixedValueLoader()

Method Summary

Modifier and Type	Method and Description
String	getLoaderDialect() The type dialect of the loader.
String	getLoaderType() The type of the loader, such as JNDI, PropertyFile, SystemProperty, etc..
String	getSpecificLoadDescription() For this particular load, where was info loaded from? This may vary from run to run based on config params.
boolean	isFlaggable() Returns true if this loader supports FlaggableType's.
boolean	isTrimmingRequiredForStringValues() If true, values for string properties are trimmed by the Trimmer of the property they are associated with.
boolean	isUnknownPropertyAProblem() If true, an unrecognized name is considered a problem that will stop application startup.
LoaderValues	load(PropertyConfigurationInternal runtimeDef, Map<String,Object> fixedNamedValues, List<PropertyValue<?>> fixedPropertyValues) Load from the passed collections of property values.
void	releaseResources() Release any resources held by this loader.
void	setUnknownPropertyAProblem(boolean isAProblem) If true, an unrecognized property name is considered a problem/error.

Methods inherited from class org.yarnandtail.andhow.load.BaseLoader

attemptToAdd, attemptToAdd, attemptToAdd, attemptToAddIfNotDuplicate, createValue, findDuplicateProperty, getClassConfig, getConfigSamplePrinter, getInstanceConfig, mapNametoProperty

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.yarnandtail.andhow.api.Loader

getClassConfig, getConfigSamplePrinter, getInstanceConfig, load

Field Detail

unknownPropertyAProblem

protected boolean unknownPropertyAProblem

Constructor Detail

BaseFixedValueLoader

public BaseFixedValueLoader()

Method Detail

load

public LoaderValues load(PropertyConfigurationInternal runtimeDef,
                         Map<String,Object> fixedNamedValues,
                         List<PropertyValue<?>> fixedPropertyValues)

Load from the passed collections of property values.

All arguements must be non-null.

Parameters:

runtimeDef - The definition of all known Properties and naming metadata

fixedNamedValues - Fixed values referenced by name

fixedPropertyValues - Fixed values reference by Property reference

Returns:

The Property values loaded by this loader and/or the problems discovered while attempting to load those Property values.

isTrimmingRequiredForStringValues

public boolean isTrimmingRequiredForStringValues()

Description copied from interface: Loader

If true, values for string properties are trimmed by the Trimmer of the property they are associated with. If false, no trimming is done. Non-String type property values (like Integer or Date type values) are not affected by this. Loaders that read from text files need to trim values to separate white space and carriage returns from the value. Loaders that read from more tightly defined sources, like reading properties from java.lang.System.getProperties(), can assume that trimming has already happened.

Specified by:

isTrimmingRequiredForStringValues in interface Loader

Returns:

isFlaggable

public boolean isFlaggable()

Description copied from interface: Loader

Returns true if this loader supports FlaggableType's.

Loaders that support FlaggableType give special 'is present' meaning to a property being present without a value, similar to a 'nix command line flag. If a Loader supports flags, it should call FlaggableType.parseFlag(String) instead of ValueType.parse(String) when a Property's ValueType is a FlaggableType. See FlagProp for an example type.

Note: Returning true from this method is only potentially applicable to Loaders that parse strings. Loaders that directly load from rich values do not parse, so the loader logic would ignore the value here.

Examples:
Loading a non-null value from the properties file entry 'name = ' would be unexpected, so a properties file Loader should return 'false' here.
However, a command line loader would be expected to support flags, so should return 'true'.

Specified by:

isFlaggable in interface Loader

Returns:

true if this loader support 'nix style flag semantics for FlaggableType Properties.

getSpecificLoadDescription

public String getSpecificLoadDescription()

Description copied from interface: Loader

For this particular load, where was info loaded from? This may vary from run to run based on config params. For instance, The PropFileLoader will look multiple places to find a properties file. This method should return the actual location it was found. Assume the text is prefixed with "This loader loaded from: ". An example would be "/home/user/config/my-props.properties" No ending punctuation should be used.

Specified by:

getSpecificLoadDescription in interface Loader

Returns:

getLoaderType

public String getLoaderType()

Description copied from interface: Loader

The type of the loader, such as JNDI, PropertyFile, SystemProperty, etc.. The actual return value is arbitrary, but should be consistent between loaders of the same type. The values returned by getLoaderType and getLoaderDialect are used to removed duplicate loader types when printing sample files. If two loader instances are of the same type and dialect, only one will print the sample file.

Specified by:

getLoaderType in interface Loader

Returns:

Must never returns null.

getLoaderDialect

public String getLoaderDialect()

Description copied from interface: Loader

The type dialect of the loader. For property files, this might be either KeyValuePair or xml for example. The actual return value is arbitrary, but should be consistent between loaders of the same type and dialect. The values returned by getLoaderType and getLoaderDialect are used to removed duplicate loader types when printing sample files. If two loader instances are of the same type and dialect, only one will print the sample file.

Specified by:

getLoaderDialect in interface Loader

Returns:

May return null if there is no meaningful dialect for this type.

setUnknownPropertyAProblem

public void setUnknownPropertyAProblem(boolean isAProblem)

Description copied from interface: ReadLoader

If true, an unrecognized property name is considered a problem/error.

Specified by:

setUnknownPropertyAProblem in interface ReadLoader

isUnknownPropertyAProblem

public boolean isUnknownPropertyAProblem()

Description copied from interface: ReadLoader

If true, an unrecognized name is considered a problem that will stop application startup. This is a safety feature because a unrecognized property name in a properties file could be a typo. For other property sources, however, like System.properties, there are many non-AndHow related values that are expected to be present, so this rule cannot be enforced.

Specified by:

isUnknownPropertyAProblem in interface ReadLoader

Returns:

releaseResources

public void releaseResources()

Description copied from interface: Loader

Release any resources held by this loader. Loaders have done their job after loading values to properties. However, they may be held in memory for auditing and reporting. To prevent holding additional resources in memory, this method is called after loading is complete.

Specified by:

releaseResources in interface Loader

Overrides:

releaseResources in class BaseLoader