java初步学习hello word
1.下载 java JDK
http://www.oracle.com/technetwork/java/javase/downloads/index.html
2.安装 JDK
3.打开命令行
输入 java
按下 Enter
你会看到
Usage: java [-options] class [args...] (to execute a class) or java [-options] -jar jarfile [args...] (to execute a jar file) where options include: -d32 use a 32-bit data model if available -d64 use a 64-bit data model if available -client to select the "client" VM -server to select the "server" VM -hotspot is a synonym for the "client" VM [deprecated] The default VM is server, because you are running on a server-class machine. -cp <class search path of directories and zip/jar files> -classpath <class search path of directories and zip/jar files> A : separated list of directories, JAR archives, and ZIP archives to search for class files. -D<name>=<value> set a system property -verbose[:class|gc|jni] enable verbose output -version print product version and exit -version:<value> require the specified version to run -showversion print product version and continue -jre-restrict-search | -jre-no-restrict-search include/exclude user private JREs in the version search -? -help print this help message -X print help on non-standard options -ea[:<packagename>...|:<classname>] -enableassertions[:<packagename>...|:<classname>] enable assertions -da[:<packagename>...|:<classname>] -disableassertions[:<packagename>...|:<classname>] disable assertions -esa | -enablesystemassertions enable system assertions -dsa | -disablesystemassertions disable system assertions -agentlib:<libname>[=<options>] load native agent library <libname>, e.g. -agentlib:hprof see also, -agentlib:jdwp=help and -agentlib:hprof=help -agentpath:<pathname>[=<options>] load native agent library by full pathname -javaagent:<jarpath>[=<options>] load Java programming language agent, see java.lang.instrument -splash:<imagepath> show splash screen with specified image java install successfull
4.打开编辑器.windows用户使用notepad,linux直接vi
(Eclipse 或者 Jbuilder 是常见的java开发工具)
写下一个小程序
public class Test { public static void main(String[] args){ System.out.println("hello java"); } }
保存到 E:\
名字为Test.java 路径 E:\Test.java
打开命令行
输入
E: E:\ javac Test.java E:\ java Test
结果:
hello java