Java first course-Java Introduction

Java is a new-generation object-oriented programming language released by Sun. It features simplicity, stability, platform independence, security, interpretation and execution, and multithreading, is currently the most widely used network programming language, mainly used for network application development.
Java can be used to generate two types of programs: Application and applet ).
Java is both an interpreted and executed language.
Java virtual machine is the core of Java programming language.
JDK provides multiple tools, which are located in the bin directory of JDK.
Pay attention to the differences and connections with C ++ when learning Java, and master the coding specifications of Java programs.

 

Java features
1. Simple
2 object-oriented
3 distributed
4 robustness
5. Security
6. Neutral Architecture
7 portability
8. Explain and execute
9 High Performance
10 Multithreading
11 dynamic

 

Java Development Tools
I. JDK
JDK (Java developer's kit) is a Java programming toolkit developed by Sun. It can be downloaded from Sun's homepage for free, includes the javac compiler, interpreter Java, debugger jdb, anti-assembler javap, Document Manager javadoc, and Applet previewer appletviewer.

JDK has several versions suitable for the following platforms
· ISCSI Solaris
· X86 Solaris
· Windows NT
· Windows 95
· Macintosh

Ii. JBuilder
The Java development tool developed by Borland is a very user-friendly and fully compatible tool with JDK. It can complete various Java, J2EE, and J2EE development work.

3. jcreator
This software is relatively small and does not have high hardware requirements. It is completely written in C ++ with fast speed and high efficiency. It was rated as "Sparrow is small but dirty ". Many functions are designed in jcreator.

Iv. Eclipse
Led by IBM, The Eclipse project has developed into a huge eclipse alliance, with more than 150 software companies involved in the Eclipse project, these include Borland, Rational Software, red hat, and Sybase. Eclipse is a development source code project. Anyone can get it for free and develop their own plug-ins on this basis. Therefore, it is getting more and more attention.

V. Symantec Café
It is a set of visual tools integrated with JDK launched by Symantec. It is suitable for developing Java applications and Java applets. The price is about $130, including Symantec's own compiler, the speed is about a dozen times faster than that of JDK.

6. IBM Visual Age for Java
Developed by IBM, it provides extensive support for visual programming, supports the use of CICs to connect genetic mainframe applications, supports EJB development applications, and supports integrated development with WebSphere, is a very mature development tool.

VII. Java Workshop
It is a multi-platform development tool launched by Sun Microsystems in the Internet environment. It is fully written in Java and features multiple users and platforms. It is suitable for interactive applet development.

 

 

 

Simple Java applications

Public class welcomejava
{
Public static void main (string ARGs [])
{
System. Out. println ("welcome to the Java World! ");
}
}

 

 

To configure JDK environment variables, follow these steps:
1. My computer --> properties --> advanced --> environment variables.
2. Configure user variables:
A. Create java_home
C:/program files/Java/j2sdk1.5.0 (JDK installation path)
B. append the path
% Java_home %/bin; % java_home %/JRE/bin
C. Create a classpath
.; % Java_home %/LIB; % java_home %/lib/tools. Jar
3. test whether the environment variable configuration is successful:
Start --> Run --> cmd
Press on the keyboard: javac Java
The corresponding command appears, rather than the error message, indicating that the configuration is successful!
 
Environment Variable Configuration:
1. PATH environment variable. The function is to specify the command search path. Execute the command below the I command line, for example, when javac compiles a Java program, it will go to the path specified by the PATH variable to check whether the corresponding command program can be found. We need to add the bin directory under the JDK installation directory to the existing PATH variable. The bin directory contains frequently used executable files such as javac/Java/javadoc waiting, after setting the PATH variable, You can execute tools such as javac and Java in any directory.
2. classpath environment variable. The function is to specify the Class search path and use the classes that have already been compiled. The premise is that you can find them, and JVM searches for classes through classpth. We need to set DT. jar and tools. jar in the Lib subdirectory under the JDK installation directory to classpath. Of course, the current directory "." must also be added to this variable.
3. java_home environment variable. It points to the JDK installation directory. Eclipse, netbeans, tomcat, and other software find and use the installed JDK by searching the java_home variable.

 

 

 

0. Java-related
Recommended:
Think in Java (http://www.bccn.net/Soft/kfyy/java/edu/200602/255.html)
Java design patterns (http://www.jdon.com/designpatterns)

1. Development Environment
Eclipse
: Http://www.eclipse.org/downloads/download.php? File =/Eclipse/downloads/drops/R-3.4.1-200809111700/eclipse-SDK-3.4.1-win32.zip
Myeclipse
: Http://www.myeclipseide.com/index.php? Name = downloads & Req = viewsdownload & SID = 31

 

2. Technical Documents
Spring
: Http://www.springsource.com/download/community? Project = spring % 20 framework
Document address: http://www.redsaga.com/spring_ref/2.5/spring-reference.pdf

Http://spring.jactiongroup.net/viewtopic.php? T = 3800 & SID = f82a6e3fa81a321d8f56c462107aa1ef

Http://chenlb.blogjava.net/archive/2008/07/11/212039.html #

Velocity
: Http://velocity.apache.org/download.cgi
Document address: http://velocity.apache.org/engine/releases/velocity-1.6.1/user-guide.html

Http://velocity.apache.org/engine/releases/velocity-1.6.1/user-guide.html

Http://velocity.apache.org/engine/releases/velocity-1.6.1/vtl-reference-guide.html

Http://www.itepub.net/html/kaifajingcui/Java/2006/0514/31402.html

Http://www.javaresearch.org/article/57183.htm
Http://java.chinaitlab.com/base/529181.html

Http://blog.csdn.net/leizhendong/archive/2008/06/26/2589406.aspx

3. forums and communities related to spring and Velocity
Http://spring.jactiongroup.net/
Http://www.javaresearch.org/
Http://www.javaeye.com/
Http://www.matrix.org.cn/forum.shtml

 

 

Official download of JDK 1.6 _ official download of JDK 6:

Http://www.java.net/download/jdk6/6u10/promoted/b32/binaries/jdk-6u10-rc2-bin-b32-windows-i586-p-12_sep_2008.exe

Download jdk6 api chm Chinese reference:

Jdk6apichinese reference 070114.rar:

Http://chinesedocument.com/upimg/soft/jdk6apichinese reference 070114.rar/

Download CHM from Java SE 6 API Chinese version:

Http://download.java.net/jdk/jdk-api-localizations/jdk-api-zh-cn/publish/1.6.0/chm/JDK_API_1_6_zh_CN.CHM

Download CHM from Java SE 5 API Chinese version:

Http://download.java.net/jdk/jdk-api-localizations/jdk-api-zh-cn/builds/JDK_API_1_5_zh_CN.CHM

Download the jdk6 API Chinese version:

Https://jdk-api-zh-cn.dev.java.net/

Jdk6 API Chinese Version HTML format online documentation: http://download.java.net/jdk/jdk-api-localizations/jdk-api-zh-cn/builds/latest/html/zh_CN/api/
Download the jdk6 API Chinese Version ZIP:

Http://download.java.net/jdk/jdk-api-localizations/jdk-api-zh-cn/builds/latest/html_zh_CN.zip

JDK 1.6 API:

Sun official API Chinese version [jdk1.6]

1.6api documentation (Chinese:
ZIP Format: http://download.java.net/jdk/jdk-api-localizations/jdk-api-zh-cn/publish/1.6.0/html_zh_CN.zip

Chm format: http://download.java.net/jdk/jdk-api-localizations/jdk-api-zh-cn/publish/1.6.0/chm/JDK_API_1_6_zh_CN.CHM