net.sf.duro

Class LocalSession

java.lang.Object

net.sf.duro.DSession

net.sf.duro.LocalSession

public class LocalSession
extends DSession

Method Summary

Modifier and Type	Method and Description
void	close() Closes the session.
java.lang.Object	evaluate(java.lang.String expr) Evaluates a Duro D/T expression.
<T> T	evaluate(java.lang.String expr, java.lang.Class<T> destClass) Evaluates expr, stores the result in an instance of class destClass and returns that instance.
void	evaluate(java.lang.String expr, java.lang.Object dest) Evaluates the expression expr and stores the value in dest.
void	execute(java.lang.String code) Executes Duro D/T code.
void	setVar(java.lang.String name, java.lang.Object v) Assigns a value to a variable.

Methods inherited from class net.sf.duro.DSession

createSession, createSession

Methods inherited from class java.lang.Object

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

Method Detail

close

public void close()

Closes the session.

Overrides:

close in class DSession

Throws:

DException - If a Duro error occurs

execute

public void execute(java.lang.String code)

Description copied from class: DSession

Executes Duro D/T code.

User-defined operators implemented in Java can be created by using the OPERATOR statement with the EXTERN keyword.

Creating a user-defined read-only operator implemented by a Java method:

OPERATOR <opname>(<parameter_list>) RETURNS <type>
EXTERN 'Java' '<classname>.<methodname>';
END OPERATOR;

The method must be static. Parameter types and return type map to Java types as described in evaluate.

Creating a user-defined update operator implemented by a Java method:

OPERATOR <opname>(<parameter_list>) UPDATES { <update_param_list> }
EXTERN 'Java' '<classname>.<methodname>';
END OPERATOR;

The method must be static. Non-update parameter types map to Java types as described in evaluate. Update parameter types map to Java classes as follows:

boolean

UpdatableBoolean

string

java.lang.StringBuilder

integer

UpdatableInteger

float

UpdatableDouble

binary

ByteArray

tuple { ... }

Tuple

relation { ... }

java.util.Set

array

java.util.ArrayList

types with declared possible representations

PossrepObject

Specified by:

execute in class DSession

Parameters:

code - The code to execute

evaluate

public java.lang.Object evaluate(java.lang.String expr)

Description copied from class: DSession

Evaluates a Duro D/T expression.

Duro types map to Java classes as follows:

boolean

java.lang.Boolean

string

java.lang.String

integer

java.lang.Integer

float

java.lang.Double

binary

byte[]

tuple { ... }

Tuple

relation { ... }

java.util.Set

array

Duro arrays map to Java arrays. For example, array integer is converted to java.lang.Integer[].

types with declared possible representations

PossrepObject

Specified by:

evaluate in class DSession

Parameters:

expr - The expression to evaluate

Returns:

an object representing the result value.

evaluate

public void evaluate(java.lang.String expr,
                     java.lang.Object dest)

Description copied from class: DSession

Evaluates the expression expr and stores the value in dest. The type of expr must have possreps and dest must have a setter for each property.

Specified by:

evaluate in class DSession

Parameters:

expr - the expression to evaluate

dest - the destination object

evaluate

public <T> T evaluate(java.lang.String expr,
                      java.lang.Class<T> destClass)

Description copied from class: DSession

Evaluates expr, stores the result in an instance of class destClass and returns that instance. If destClass is an interface, a dynamic proxy is created. Otherwise, the default constructor of destClass is called.

Specified by:

evaluate in class DSession

Parameters:

expr - the expression to evaluate

destClass - the class or interface the returned object is an instance of.

Returns:

an object of class destClass representing the result value.

setVar

public void setVar(java.lang.String name,
                   java.lang.Object v)

Assigns a value to a variable.

Specified by:

setVar in class DSession

Parameters:

name - The name of the variable

v - The value

Throws:

DException - If a Duro error occurs.

java.lang.IllegalArgumentException - If v does not match the type of the variable.