VariableAccess

All Known Subinterfaces:

VariableAccessArray_ifc

All Known Implementing Classes:

ByteDataSymbolicAccess.Variable, VariableAccessWithBitmask, VariableAccessWithIdx
```
public interface VariableAccess_ifc
```
This interface describes the access to any form of variable. A variable may be a field gotten with reflection, see implementation org.vishia.reflect.FieldJcVariableAccess (srcJava_vishiaRun). A variable may be a entity in a byte-datagram, see ByteDataSymbolicAccess.Variable. The quality of a variable and the kind of access is described in the implementation. The user can access to a substantial variable with this interface.

It is possible to have one list or index with variables which are found in several data storage types, for example in Java-data using org.vishia.reflect.FieldJcVariableAccess (srcJava_vishiaRun) or in data from files. use Container List < VariableAccess_ifc > or Map < String,VariableAccess_ifc >. To work as integral whole, this interface supports all of them.

Variables may assembled in an array structure. The implementation knows about the array property of any variable. To support an indexed access all methods can have additional index parameter. If they are not need, let it empty. If indices are given but they are not expected, an IndexOutOfBoundsException or an IllegalArgumentException may be thrown.

Field Summary

Fields
Modifier and Type Field and Description

static int version
Version, history and license.

Fields
Modifier and Type	Field and Description
`static int`	`version` Version, history and license.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`double`	`getDouble()` Gets the value from this variable.
`float`	`getFloat()` Gets the value from this variable.
`int`	`getInt()` Gets a integer value from this variable.
`long`	`getLastRefreshTime()` Gets the time stamp when this variable was refreshed lastly.
`int[]`	`getLastRefreshTimeShort()` Returns a pair of timeShort and timeShortAdd (see `Timeshort`) of the last refresh time if timeAbs is not available or the necessary resolution should be finer than 1 ms.
`long`	`getLong()` Gets a long value from this variable.
`java.lang.String`	`getString()` Gets the value from this variable.
`char`	`getType()` Returns the type of the variable:
`boolean`	`isRefreshed()` Returns true if the variable was refreshed after it was requested.
`boolean`	`isRequestedValue(long timeEarlyRequested, boolean retryFaultyVariables)` Returns true if the request is newer than the last refresh.
`void`	`requestValue()` Requests a new value from the target device with the `System.currentTimeMillis()`
`void`	`requestValue(long timeRequested)` Requests a new value from the target device.
`void`	`requestValue(long timeRequested, java.lang.Runnable run)` Requests a new value from the target device.
`double`	`setDouble(double value)` Sets the value from this variable.
`float`	`setFloat(float value)` Sets the value from this variable.
`int`	`setInt(int value)` Sets the value into the variable.
`long`	`setLong(long value)` Sets the value into the variable.
`void`	`setRefreshed(long time)`
`java.lang.String`	`setString(java.lang.String value)` Sets the value into the variable

- Field Detail
  - version
```
static final int version
```
    Version, history and license.
    - 2016-01-23 Hartmut new getLastRefreshTimeShort()
    - 2016-01-23 Hartmut chg: isRequestedValue(long, boolean) with time parameter for earliest request.
    - 2014-05-22 Hartmut new: isRefreshed(), implemented in all implementors.
    - 2014-01-10 Hartmut new enhancement of #requestValue(long, Runnable) with Runnable.
    - 2013-12-10 Hartmut new Separate {@link VariableAccessArray_ifc} and this interface. All simple accesses and especially {@link VariableAccessWithIdx} need this interface. All implementations need the {@link VariableAccessArray_ifc} if they support arrays.
    - 2012-09-24 Hartmut new {@link #getLong(int...)} and {@link #setLong(long, int...)}
    - 2012-04-25 Hartmut new {@link #requestValue(long)}, {@link #getLastRefreshTime()}: A variable should be refreshed by determined call of {@link #requestValue(long)} if it holds a value from a remote device.
    - 2012-03-31 Hartmut enhanced {@link #getType()}
    - 2010-06-00 Hartmut created to access values in an UDP-telegram with given positions. The interface permits an access independent of the concrete implementation.
    Copyright/Copyleft: For this source the LGPL Lesser General Public License, published by the Free Software Foundation is valid. It means:
    1. You can use this source without any restriction for any desired purpose.
    2. You can redistribute copies of this source to everybody.
    3. Every user of this source, also the user of redistribute copies with or without payment, must accept this license for further using.
    4. But the LPGL ist not appropriate for a whole software product, if this source is only a part of them. It means, the user must publish this part of source, but don't need to publish the whole source of the own product.
    5. You can study and modify (improve) this source for own using or for redistribution, but you have to license the modified sources likewise under this LGPL Lesser General Public License. You mustn't delete this Copyright/Copyleft inscription in this source file.
    If you are intent to use this sources without publishing its usage, you can get a second license subscribing a special contract with the author.
    See Also:
    
    Constant Field Values
- Method Detail
  - getInt
```
int getInt()
```
    Gets a integer value from this variable. The variable contains the information, whether it is long, short etc. If the variable contains a long value greater as the integer range, an IllegalArgumentException may be thrown or not, it depends on the implementation. If the variable is a float or double it may be convert to the integer format. If the variable is a boolean, it is converted to 0 or 1.
    
    Parameters:
    
    ixArray - unused if it isn't an indexed variable.
    
    Returns:
    
    the value.
  - setInt
```
int setInt(int value)
```
    Sets the value into the variable. If the variable is of byte or short type and the value is not able to present, an IllegalArgumentException may be thrown or not, it depends on the implementation.
    
    Parameters:
    
    value - The value given as int.
    
    ixArray - unused if it isn't an indexed variable.
    
    Returns:
    
    The value really set (maybe more imprecise).
  - getLong
```
long getLong()
```
    Gets a long value from this variable. The variable contains the information, whether it is long, short etc. If the variable is a float or double it may be convert to the long format. If the value is not able to present, an IllegalArgumentException may be thrown or not, it depends on the implementation. If the variable is a boolean, it is converted to 0 or 1.
    
    Parameters:
    
    ixArray - unused if it isn't an indexed variable.
    
    Returns:
    
    the value.
  - setLong
```
long setLong(long value)
```
    Sets the value into the variable. If the variable is of byte, short or int type and the value is not able to present, an IllegalArgumentException may be thrown or not, it depends on the implementation.
    
    Parameters:
    
    value - The value given as int.
    
    ixArray - unused if it isn't an indexed variable.
    
    Returns:
    
    The value really set (maybe more imprecise).
  - getFloat
```
float getFloat()
```
    Gets the value from this variable. If the variable is in another format than float, a conversion to be will be done.
    
    Parameters:
    
    ixArray - unused if it isn't an indexed variable.
    
    Returns:
    
    the value.
  - setFloat
```
float setFloat(float value)
```
    Sets the value from this variable.
    
    Parameters:
    
    ixArray - unused if it isn't an indexed variable.
    
    Returns:
    
    the value.
  - getDouble
```
double getDouble()
```
    Gets the value from this variable. If the variable is in another format than double, a conversion to be will be done.
    
    Parameters:
    
    ixArray - unused if it isn't an indexed variable.
    
    Returns:
    
    the value.
  - setDouble
```
double setDouble(double value)
```
    Sets the value from this variable. If the variable is from float type, and the range (exponent) is able to present in float, the value will be stored in float with truncation of digits.
    
    Parameters:
    
    ixArray - unused if it isn't an indexed variable.
    
    Returns:
    
    the value.
  - getString
```
java.lang.String getString()
```
    Gets the value from this variable. If the variable is numerical, it is converted to a proper representation.
    
    Parameters:
    
    ixArray - unused if it isn't an indexed variable.
    
    Returns:
    
    the value.
  - setString
```
java.lang.String setString(java.lang.String value)
```
    Sets the value into the variable
    
    Parameters:
    
    value - The value given as String.
    
    ixArray - unused if it isn't an indexed variable.
    
    Returns:
    
    The value really set (maybe shortened).
  - requestValue
```
void requestValue(long timeRequested)
```
    Requests a new value from the target device.
    
    Parameters:
    
    timeRequested - the current time, used to mark the request.
  - requestValue
```
void requestValue()
```
    Requests a new value from the target device with the System.currentTimeMillis()
  - requestValue
```
void requestValue(long timeRequested,
                  java.lang.Runnable run)
```
    Requests a new value from the target device.
    
    Parameters:
    
    timeRequested - the current time
    
    run - method which should be invoked if the request is resolved, optional operation.
  - isRequestedValue
```
boolean isRequestedValue(long timeEarlyRequested,
                         boolean retryFaultyVariables)
```
    Returns true if the request is newer than the last refresh.
    
    Parameters:
    
    timeEarlyRequested - The earliest time where the variable is requested. If the request time is more early, it is not regarded. This is since 2016-01. An old request should be ignored but the time stamp of the request should be visible for debug or view the state.
    
    retryFaultyVariables - A variable which is set to invalid is requested though.
    
    Returns:
    
    true if a new value should be gotten from target.
  - isRefreshed
```
boolean isRefreshed()
```
    Returns true if the variable was refreshed after it was requested. false if the variable was never requested or it was requested and not refreshed after them.
  - setRefreshed
```
void setRefreshed(long time)
```
  - getLastRefreshTime
```
long getLastRefreshTime()
```
    Gets the time stamp when this variable was refreshed lastly.
    
    Returns:
    
    -1 if this function is not supported, 0 if this variable was never set.
  - getLastRefreshTimeShort
```
int[] getLastRefreshTimeShort()
```
    Returns a pair of timeShort and timeShortAdd (see Timeshort) of the last refresh time if timeAbs is not available or the necessary resolution should be finer than 1 ms.
    
    Returns:
    
    null if this operation is not supported. Elsewhere an array with at least 2 elements. The first element[0] is the timeShort, the second [1] is timeShortAdd. The timeShortAdd may be 0.
  - getType
```
char getType()
```
    Returns the type of the variable:
    
    Returns:
    
    B, S, I, J, F, D, s for byte, short, integer, long, float, double and string.

Interface VariableAccess_ifc

Field Summary

Method Summary

Field Detail

version

Method Detail

getInt

setInt

getLong

setLong

getFloat

setFloat

getDouble

setDouble

getString

setString

requestValue

requestValue

requestValue

isRequestedValue

isRefreshed

setRefreshed

getLastRefreshTime

getLastRefreshTimeShort

getType