Hashtable Chilkat2 Java Reference Documentation

Hashtable

Current Version: 11.7.0

Markdown version of this page for AI tools (v 11.7.0) · all AI docs

Chilkat.Hashtable

Store, look up, remove, enumerate, import, and serialize key/value pairs.

Chilkat.Hashtable provides a simple key/value collection for storing string and integer values by key. It can add or replace entries, look up values, test whether keys exist, remove entries, count items, enumerate keys, import URL query parameters, serialize values back to a query string, and save or load the table in XML format.

String and integer values

Store values as strings or integers using straightforward add, replace, and lookup methods.

Fast key lookup

Check whether a key exists and retrieve its value without manually scanning a list or parsing text.

Add, replace, and remove

Maintain a mutable collection by adding new entries, replacing existing values, removing individual keys, or clearing the table.

Enumerate keys

Retrieve the set of keys when application logic needs to loop through the stored entries.

Query string helpers

Import URL query parameters into the table and serialize the table back to a query-string representation.

XML persistence

Save the hashtable to XML or reload it from XML when values need to be persisted or transferred in a simple structured format.

Common pattern: Use Hashtable when application code needs a small mutable key/value table, especially for lookup tables, parsed query parameters, or simple string/integer settings. Add values with AddStr or AddInt, retrieve them with LookupStr or LookupInt, and use XML or query-string methods when the table needs to be saved, loaded, or converted.

For an extended overview, see Hashtable Class Overview.

Object Creation

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Hashtable;

try (Hashtable hashtable = new Hashtable()) {
    // ... use hashtable ...
} catch (ChilkatException e) {
    System.out.println(e.getMessage());          // "Hashtable.someMethod failed: <reason>"
    System.out.println(e.getLastErrorText());    // the full log of the failed call
}

public Hashtable()

Creates the underlying native Chilkat object. The native library (chilkat2java) is loaded the first time any Chilkat2 object is created; see the README in the download for where it is looked for (-Dchilkat2.library.path, a classpath resource, or java.library.path).

public void close()

Releases the native object (Hashtable is AutoCloseable, so try-with-resources calls it). Calling it again does nothing; any other method or property accessor called afterwards throws IllegalStateException. An object that is never closed is freed by a background cleaner once it becomes unreachable, but the garbage collector does not see native memory, so closing is the normal path. Objects returned by methods are owned by the caller too.

public boolean isClosed()

Returns true once close() has been called.

Errors

A method that fails throws ChilkatException, an unchecked exception carrying getClassName(), getMethodName(), getReason() (one line, also in the message) and getLastErrorText() (the full log, captured at the moment of the failure). The object remains usable. Methods that look something up and find nothing return null instead of throwing (each such method says so), and methods that answer a question (hasMember, isUnlocked, ...) return a plain boolean. Property accessors do not throw for Chilkat reasons.

A null string or object argument throws NullPointerException naming the parameter (except where a method documents that null is accepted), and a string containing U+0000 throws IllegalArgumentException.

Use an object from one thread at a time; it may be handed from one thread to another. The one cross-thread operation is setting setAbortCurrent(true) on an object that is busy in another thread (on the classes that have AbortCurrent). Unlocking: call new Global().unlockBundle("...") once at startup.

Properties

Count

// read-only
int getCount()

Introduced in version 9.5.0.97

The number of entries currently stored in the hashtable.

Each key contributes one entry regardless of whether its value is a string or an integer. Adding a new key increases Count; replacing the value of an existing key does not. Removing an entry decreases it, and Clear resets it to 0.

Term	Meaning
`Count`	The number of stored entries.
Capacity	The number of hash buckets, not a maximum entry count.

Hashtable Chilkat2 Java Reference Documentation

Hashtable

Current Version: 11.7.0

Store, look up, remove, enumerate, import, and serialize key/value pairs.

String and integer values

Fast key lookup

Add, replace, and remove

Enumerate keys

Query string helpers

XML persistence

Object Creation

Errors

Properties

Count

DebugLogFilePath

LastErrorHtml

LastErrorText

LastErrorXml

LastMethodSuccess

VerboseLogging

Version

Methods

AddFromXmlSb

AddInt

AddQueryParams

AddStr

Clear

ClearWithNewCapacity

Contains

ContainsIntKey

GetKeys

LookupInt

LookupStr

Remove

ToQueryString

ToXmlSb