[root@centos ~]# javac
Usage: javac
where possible options include:
@ Read options and filenames from file
-Akey[=value] Options to pass to annotation processors
--add-modules (,)*
Root modules to resolve in addition to the initial modules, or all modules
on the module path if is ALL-MODULE-PATH.
--boot-class-path , -bootclasspath
Override location of bootstrap class files
--class-path , -classpath , -cp
Specify where to find user class files and annotation processors
-d Specify where to place generated class files
-deprecation
...
...
（2）测试java
[root@centos ~]# java
Usage: java [options] [args...]
(to execute a class)
or java [options] -jar [args...]
(to execute a jar file)
or java [options] -m [/] [args...]
java [options] --module [/] [args...]
(to execute the main class in a module)
...
...
（3）查看JDK版本信息
[root@centos ~]# java -version
java version "9.0.1"
Java(TM) SE Runtime Environment (build 9.0.1+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.1+11, mixed mode)
[root@centos ~]#
jshell> /help
| Type a Java language expression, statement, or declaration.
| Or type one of the following commands:
| /list [|-all|-start]
| list the source you have typed
| /edit
| edit a source entry referenced by name or id
| /drop
| delete a source entry referenced by name or id
| /save [-all|-history|-start]
| Save snippet source to a file.
| /open
| open a file as source input
| /vars [|-all|-start]
| list the declared variables and their values
| /methods [|-all|-start]
| list the declared methods and their signatures
| /types [|-all|-start]
| list the declared types
| /imports
| list the imported items
| /exit
| exit jshell
| /env [-class-path ] [-module-path ] [-add-modules ] .
| view or change the evaluation context
| /reset [-class-path ] [-module-path ] [-add-modules ]
| reset jshell
| /reload [-restore] [-quiet] [-class-path ] [-module-path ]...
| reset and replay relevant history -- current or previous (-restore)
| /history
| history of what you have typed
| /help [|]
| get information about jshell
| /set editor|start|feedback|mode|prompt|truncation|format ...
| set jshell configuration information
| /? [|]
| get information about jshell
| /!
| re-run last snippet
| /
| re-run snippet by id
| /-
| re-run n-th previous snippet
|
| For more information type '/help' followed by the name of a
| command or a subject.
| For example '/help /list' or '/help intro'.
|
| Subjects:
|
| intro
| an introduction to the jshell tool
| shortcuts
| a description of keystrokes for snippet and command completion,
| information access, and automatic code generation
| context
| the evaluation context options for /env /reload and /reset
jshell>
声明： 本文只为方便我个人查阅和理解，详细的分析以及源代码请移步 原作者的博客http://chjavach.iteye.com/
public class Singleton {
}
/*
* 懒汉模式。注意，getInstance如果在多线程环境中调用，需要加上synchronized，否则存在线程不安全问题
*/
class LazySingleton
这个月公司安排我一个人做iOS客户端开发，由于急着用，我先发布一个版本，由于第一次发布iOS应用，期间出了不少问题，记录于此。
1、使用Application Loader 发布时报错：Communication error.please use diagnostic mode to check connectivity.you need to have outbound acc
/*
2013年3月15日15:16:24
malloc 就memory(内存) allocate(分配)的缩写
本程序没有实际含义，只是理解使用
*/
# include <stdio.h>
# include <malloc.h>
int main(void)
{
int i = 5; //分配了4个字节 静态分配
int * p
http://wiki.sdn.sap.com/wiki/display/BOBJ/Optimize+query+with+Query+Stripping+in+Web+Intelligence
and a very straightfoward video
http://www.sdn.sap.com/irj/scn/events?rid=/library/uuid/40ec3a0c-936
