Java Program to List all declared methods in a class.

The Java Class Library (JCL) is a set of dynamically loadable libraries that Java applications can call at run time. Because the Java Platform is not dependent on a specific operating system, applications cannot rely on any of the platform-native libraries. Instead, the Java Platform provides a comprehensive set of standard class libraries, containing the functions common to modern operating systems.

JCL serves three purposes within the Java Platform:

Like other standard code libraries, they provide the programmer a well-known set of useful facilities, such as container classes and regular expression processing.
The library provides an abstract interface to tasks that would normally depend heavily on the hardware and operating system, such as network access and file access.
Some underlying platforms may not support all of the features a Java application expects. In these cases, the library implementation can either emulate those features or provide a consistent way to check for the presence of a specific feature.

Collections and Utilities : built-in Collection data structures, and utility classes, for Regular expressions, Concurrency, logging and Data compression.
Sound: interfaces and classes for reading, writing, sequencing, and synthesizing of sound data.
XML: SAX, DOM, StAX, XSLT transforms, XPath and various APIs for Web services, as SOAP protocol and JAX-WS.
CORBA and RMI APIs, including a built-in ORB

Keyword list. Like the light makes things visible, keywords make a Java program meaningful. Each term tells us what a part of the program does.

abstract
boolean
break
byte
case
catch
class
continue
default
do
double
else
enum
extends
false
final
finally
float
for
if
implements
import
int
interface
long
new
null
package
private
protected
public
return
short
static
super
switch
this
throw
throws
true
try
void
while

Common classes. Programs use classes to create complex models and perform various tasks. With keywords we specify and create these classes. Here are some important classes.
ArrayDeque
ArrayList
Arrays
BitSet
BufferedReader
BufferedWriter
Character
Calendar
Collections
Comparable
Comparator
Date
EnumMap
Exception
Files
HashMap
HashSet
Hashtable
InputStream
InputStreamReader
Integer
IntStream
Matcher
Math
Object
Objects
Optional
Pattern
PriorityQueue
Process
ProcessBuilder
Random
Runtime
Stack
StackOverflowError
Stream
String
StringBuffer
StringBuilder
TreeMap
URI
URL
Vector