Eclipse learning (1) Learning (1)
1. Why do I need eclipse?
When you use the Command-Line compiler - Javac, you will encounter such as: missing the import statement, forgetting the variable declaration, etc., there will be a series of error messages. The error message reported that Javac knows what type of error, but why can't you fix these errors directly? Because Javac is not an editor, it can't fix an error. In order to change this, we have to use the IDE (Integrated Development Environment integration development environment).
Java's IDE has many, such as Borland's JBuilder, IBM's Visual Age for Java, WebSphere Studio, Oracle's JDeveloper, Sun's Forte for Java. Here is Eclipse, which is a very famous open source project. Eclipse was originally created by Object Technology Technologies International and IBM's IDE product development group, starting from April 1999. IBM provides the initial Eclipse code foundation, including Platform, JDT, and PDE. It is currently led by IBM, which has developed around the Eclipse project, has become a huge Eclipse alliance, and more than 150 software companies are involved in the Eclipse project, including Borland, Rational Software, Red Hat and Sybase, recent Oracle also plans to join the Eclipse Alliance in. It is there is a continuous contribution and innovation of IBM's source of dollars and excellent software developers around the world. Eclipse received 2004 Jolt Best IDE Awards, JDJ editing recommended IDE and other awards.
In addition, Eclipse also brings a new development mode - based on plug-ins. The value of Eclipse is that it provides a development source platform for the creation of an extensible integrated development environment. This platform allows anyone to build tools for seamless integration with environment and other tools. The key to the seamless integration of tools and eclipse is plugin. In addition to small runtime kernels, all things in Eclipse are plugins.
2. Eclipse and Java
Although Eclipse can be used as a different language - from C / C to COBOL - IDE, it is mainly as Java IDE, which has built-in support for Java.
During Java development, Eclipse can handle problems that Javac can solve, which gives an error message before compiling and adds suggestions for solving problems.
3. Eclipse background
Eclipse as an open source project, is divided into three sub-projects: ※ The Eclipse platform itself, which constitutes the pillar of the entire application;
※ Java Development Kit (JDT: Java Development Toolkit)
※ Plug-in development environment (PDE: PLUG-IN Development Environment), which is capable of eclipse development tools - plugins.
These different subprojects can also be subdivided into other sub-projects, such as the JDT sub-project, which is composed of a user interface (UI: user interface, kernel, and debug sub).
4. About public license CPL (Common public license) Eclipse is open source software. Open source software comes with a license to ensure that certain rights grants users are included in the release. Of course, the most obvious right is that the source code must be available so that users can freely modify and distribute the software. The protection of this user rights is done by a policy called Copyleft: software license proposes version protection unless clearly grants the right to users, the user does not score the software. Copyleft also requires the same license to cover any software that is redistributed. This actually inverted version of the purpose - using the version to grant user rights, not the copyright of the software developer --CopyLeft is often described as "all versions".
Open Software Initiative is a non-profit organization that explicitly defines the meaning of open source and certification licenses that meet their standards. Eclipse is a granted license based on OSI-approved General Public License (CPL) 1.0 version, CPL "aims to promote commercial use of procedures ..."
Creating a plug-in for Eclipse or develops Eclipse as a developer based on the software development application, requiring any Eclipse code that they use or modified under the CPL, but they can freely determine the license grant method of the code you added. The proprietary code packaged with the software from Eclipse does not need to grant licenses as an open source, and the source code does not need to be provided to the user.
Although most developers do not use Eclipse to develop plugins, or create an Eclipse-based new product, but Eclipse's open source, not just it makes Eclipse free available (although it means easy to commercialized license means Plugins may have to spend money). Open source code encourages innovation, and motivates developers (even commercial developers) contribute to the public open source. There are many reasons for this, but the more essential causes, the more developers contributing to this project, the project will become more precious for everyone. As this project becomes more useful, more developers will use it and form a community around it, just like those communities formed around Apache and Linux.
5. How do I download and install Eclipse?
Download: Visit http://www.eclipse.org/downloads page, select Download Mirror on this page. Usually, we should choose the latest Eclipse version (currently the latest Eclipse version)
3.0.1). Then select the Eclipse SDK under the corresponding operating system.
Eclipse SDK includes an Eclipse platform, Java Development Tool (JDT), and plug-in development environment (PDE) and includes source code and documents for all users and programmers. Eclipse does not include a Java runtime environment (JRE). So you need to install one in advance
1.4.1 or later Java runtime or Java Development Pack (JDK).
Installation: Installing Eclipse is not complicated, just decompressed the file. Windows users will find that Eclipse does not use Windows registry, so install (reinstallation) Eclipse is very simple.
