Java Program to List all declared methods in a class. смотреть онлайн

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.

java.lang contains fundamental classes and interfaces closely tied to the language and runtime system.
I/O and networking access the platform file system, and more generally networks through the java.io, java.nio and java.net packages. For networking, SCTP is available through com.sun.nio.sctp.
Mathematics package: java.math provides mathematical expressions and evaluation, as well as arbitrary-precision decimal and integer number datatypes.
Collections and Utilities : built-in Collection data structures, and utility classes, for Regular expressions, Concurrency, logging and Data compression.
GUI and 2D Graphics: the AWT package (java.awt) basic GUI operations and binds to the underlying native system. It also contains the 2D Graphics API. The Swing package (javax.swing) is built on AWT and provides a platform-independent widget toolkit, as well as a Pluggable look and feel. It also deals with editable and non-editable text components.
Sound: interfaces and classes for reading, writing, sequencing, and synthesizing of sound data.
Text: java.text deals with text, dates, numbers, and messages.
Image package: java.awt.image and javax.imageio provide APIs to write, read, and modify images.
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
Security is provided by java.security and encryption services are provided by javax.crypto.
Databases: access to SQL databases via java.sql
Access to Scripting engines: The javax.script package gives access to any conforming Scripting language.
Applets: java.applet allows applications to be downloaded over a network and run within a guarded sandbox
Java Beans: java.beans provides ways to manipulate reusable components.
Introspection and reflection: java.lang.Class represents a class, but other classes such as Method and Constructor are available in java.lang.reflect.


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