Package edu.wpi.first.wpilibj
Class Preferences
- java.lang.Object
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- edu.wpi.first.wpilibj.Preferences
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public final class Preferences extends Object
The preferences class provides a relatively simple way to save important values to the roboRIO to access the next time the roboRIO is booted.This class loads and saves from a file inside the roboRIO. The user can not access the file directly, but may modify values at specific fields which will then be automatically saved to the file by the NetworkTables server.
This class is thread safe.
This will also interact with
NetworkTable
by creating a table called "Preferences" with all the key-value pairs.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
containsKey(String key)
Returns whether or not there is a key with the given name.boolean
getBoolean(String key, boolean backup)
Returns the boolean at the given key.double
getDouble(String key, double backup)
Returns the double at the given key.float
getFloat(String key, float backup)
Returns the float at the given key.static Preferences
getInstance()
Returns the preferences instance.int
getInt(String key, int backup)
Returns the int at the given key.Vector<String>
getKeys()
Gets the vector of keys.long
getLong(String key, long backup)
Returns the long at the given key.String
getString(String key, String backup)
Returns the string at the given key.void
putBoolean(String key, boolean value)
Puts the given boolean into the preferences table.void
putDouble(String key, double value)
Puts the given double into the preferences table.void
putFloat(String key, float value)
Puts the given float into the preferences table.void
putInt(String key, int value)
Puts the given int into the preferences table.void
putLong(String key, long value)
Puts the given long into the preferences table.void
putString(String key, String value)
Puts the given string into the preferences table.void
remove(String key)
Remove a preference.void
removeAll()
Remove all preferences.
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Method Detail
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getInstance
public static Preferences getInstance()
Returns the preferences instance.- Returns:
- the preferences instance
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putString
public void putString(String key, String value)
Puts the given string into the preferences table.- Parameters:
key
- the keyvalue
- the value- Throws:
NullPointerException
- if value is null
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putInt
public void putInt(String key, int value)
Puts the given int into the preferences table.- Parameters:
key
- the keyvalue
- the value
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putDouble
public void putDouble(String key, double value)
Puts the given double into the preferences table.- Parameters:
key
- the keyvalue
- the value
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putFloat
public void putFloat(String key, float value)
Puts the given float into the preferences table.- Parameters:
key
- the keyvalue
- the value
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putBoolean
public void putBoolean(String key, boolean value)
Puts the given boolean into the preferences table.- Parameters:
key
- the keyvalue
- the value
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putLong
public void putLong(String key, long value)
Puts the given long into the preferences table.- Parameters:
key
- the keyvalue
- the value
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containsKey
public boolean containsKey(String key)
Returns whether or not there is a key with the given name.- Parameters:
key
- the key- Returns:
- if there is a value at the given key
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remove
public void remove(String key)
Remove a preference.- Parameters:
key
- the key
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removeAll
public void removeAll()
Remove all preferences.
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getString
public String getString(String key, String backup)
Returns the string at the given key. If this table does not have a value for that position, then the given backup value will be returned.- Parameters:
key
- the keybackup
- the value to return if none exists in the table- Returns:
- either the value in the table, or the backup
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getInt
public int getInt(String key, int backup)
Returns the int at the given key. If this table does not have a value for that position, then the given backup value will be returned.- Parameters:
key
- the keybackup
- the value to return if none exists in the table- Returns:
- either the value in the table, or the backup
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getDouble
public double getDouble(String key, double backup)
Returns the double at the given key. If this table does not have a value for that position, then the given backup value will be returned.- Parameters:
key
- the keybackup
- the value to return if none exists in the table- Returns:
- either the value in the table, or the backup
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getBoolean
public boolean getBoolean(String key, boolean backup)
Returns the boolean at the given key. If this table does not have a value for that position, then the given backup value will be returned.- Parameters:
key
- the keybackup
- the value to return if none exists in the table- Returns:
- either the value in the table, or the backup
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getFloat
public float getFloat(String key, float backup)
Returns the float at the given key. If this table does not have a value for that position, then the given backup value will be returned.- Parameters:
key
- the keybackup
- the value to return if none exists in the table- Returns:
- either the value in the table, or the backup
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getLong
public long getLong(String key, long backup)
Returns the long at the given key. If this table does not have a value for that position, then the given backup value will be returned.- Parameters:
key
- the keybackup
- the value to return if none exists in the table- Returns:
- either the value in the table, or the backup
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