Chapter 1 Java Classes and Interfaces

jaguar.util.<object>Holder class

Description

package com.sybase.jaguar.util;
public class <object>Holder  extends Object 

For components that use the Jaguar-JDBC type mappings, holder classes are used to pass INOUT parameters to component method calls. Each holder class has a value field that contains instances of a specific object or base Java type.

Additional holder classes are defined in packages com.sybase.jaguar.util.jdbc102 and com.sybase.jaguar.util.jdbc11.

com.sybase.jaguar.util holder classes are summarized in the Table 1-2.

Constructors

<object>Holder()

Default constructor that assigns the default value specified in Table 1-2.

<object>Holder(<object> initialValue)

Constructor that takes an initial value specified as initialValue. initialValue is an instance of the appropriate datatype as specified in Table 1-2.

value

The current value contained by the holder object. Table 1-2 lists the datatypes and default values for the value field.

Usage

Java component methods on the server receive INOUT parameters as a holder object. The method should set the value field of each holder object before returning.

The examples below illustrate how to construct and use holder objects:

• Each holder object has a default constructor that takes no arguments. For example:

  StringHolder str_holder = new  StringHolder();
  IntegerHolder int_holder = new  IntegerHolder();

• Each holder object has an additional constructor that takes an initial value as a parameter. For example:

  StringHolder  str_holder = 
                   new  StringHolder("hello");
  IntegerHolder  int_holder = new IntegerHolder(43);
  
  float  f = 3.141;
  FloatHolder float_holder = new  FloatHolder(f);

• Each holder object has a value member that allows access to the base object value. For example:

  IntegerHolder  i_hold = new IntegerHolder();
  System.out.println(
    "IntegerHolder  default value is:"
    + i_hold.value);

See Also

jaguar.util.jdbc102.<object>Holder class, jaguar.util.jdbc11.<object>Holder class

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