Analysis of jdk, jre, ide concepts
1.What is jdk? What's in there?
jdk, the full English name is java development kit (java development kit). It is a collection of utilities and documentation. There are java workers (.exe executable files such as javac.exe, java.exe, debuger.exe, jar.exe, javadoc.exe, etc.) and java basic class libraries (jar packages such as java.io, java.sql, java.lang, java.util, etc.). It's for developers.
2. What is the use of the things in the jdk?
2.1 java tools:
javac.exe (compiler): convert the source program (.java file) into a bytecode.class file.
java.exe (interpreter): run and compile the .claa file.
jdb.exe (debugger): error checking tool
jar.exe (packaging tool): package related class files into one file
javadoc.exe (document generator): extract documentation from source code comments
appletviewer.exe (appletviewer.exe browser): A Java browser that executes Java applets on HTML files.
2.2 java basic class library (jar package):
java.lang: This is the basic class of the system, such as String, etc. are all here, this package is the only package that can be used without importing.
java.io: Here are all input and output related classes, such as file operations.
java.nio: A new package written in order to improve the functions in the io package and improve the performance of the io package, such as NIO non-blocking application java.net: There are network-related classes, such as URL, URLConnection, etc.
java.util: This is a system auxiliary class, especially the collection classes Collection, List, Map, etc.
java.sql: This is the class of database operations, Connection, Statement, ResultSet, etc.
javax.servlet: This is the class used by JSP, Servlet, etc.
3. What is jre? What is the use?
The full English name of jre is java runtime environment (java runtime environment), which includes JVM (java virtual machine), java basic class library and supporting files. It is user-oriented. It is the runtime platform for .class files.
4. What is the relationship between jdk and jre?
When you install jdk, jre is installed along with it. You can think that jre is part of jdk (java development kit).
For details, please refer to: http://www.cnblogs.com/yezhenhan/archive/2011/01/02/1924307.html
5.ide是什么？有什么用？
ide英文全称是integreted development environment（集成开发环境）。
在这个集成开发环境下，我们可以更方便地组织和管理自己写的代码（工作空间+资源管理器），我们可以通过它提供的一些按钮控件更简单地去调用jdk提供的java工具。
Eclipse，myEclipse，Jbuilder等应用软件就为我们提供了ide（集成开发环境），有些人把IDE看作是这类应用软件的统称。
6.jdk与ide之间有什么关系？区别？
6.1可以没有IDE，但不能没有JDK。
没有IDE，我们也可使用记事本编写.java源代码，然后再使用JDK提供的java编译器，java解释器等，运行代码。
6.2有IDE，也不能没有JDK。
有了IDE，一方面，能够方便我们更好地组织和管理自己写的代码（特别是在开发大型项目时）。另一方面，它能够帮助我们更简便地去操作JDK，不用苦逼地使用命令行操作JDK。
其它：
1.java程序从创建到运行之间的过程是什么？与C程序的有什么区别？
java:
c:
最后：jar-可以看作是.class文件的集合，通常称作java包