一、JDK、JRE
术语名 | 缩写 | 解释 |
Java Development Kit | JDK | Java程序员用的工具包 |
Java Runtime Enviroment | JRE | Java程序的运行环境 |
二、下载、安装JDK
官网下载链接:http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
百度网盘下载链接:http://pan.baidu.com/s/1bLnANG
鼠标右键双击运行.exe,将会弹出引导程序安装JDK和JRE,
点击next,继续安装
点击change..选择你安装的路径,然后点击next
等待一会儿,会弹出安装jre的向导
可以选择安装路径,点击change选择安装路径,然后点击next
点击next steps去查看官网文档API等,点击close完成安装
三、环境变量配置
安装完成,cd到你的安装路径下
安装路径如下图:
那两个文件夹分别是JDK和JRE的安装位置,cd到JDK\bin中执行Java命令
F:\Java\JDK\bin>dir Volume in drive F has no label. Volume Serial Number is 692A-C80C Directory of F:\Java\JDK\bin // : <DIR> . // : <DIR> .. // : , appletviewer.exe // : , extcheck.exe // : , idlj.exe // : , jabswitch.exe // : , jar.exe // : , jarsigner.exe // : , java-rmi.exe // : , java.exe // : , javac.exe // : , javadoc.exe // : , javafxpackager.exe // : , javah.exe // : , javap.exe // : , javapackager.exe // : , javaw.exe // : , javaws.exe // : , jcmd.exe // : , jconsole.exe // : , jdb.exe // : , jdeps.exe // : , jhat.exe // : , jinfo.exe // : , jjs.exe // : , jli.dll // : , jmap.exe // : , jmc.exe // : jmc.ini // : , jps.exe // : , jrunscript.exe // : , jsadebugd.exe // : , jstack.exe // : , jstat.exe // : , jstatd.exe // : , jvisualvm.exe // : , keytool.exe // : , kinit.exe // : , klist.exe // : , ktab.exe // : , msvcr100.dll // : , native2ascii.exe // : , orbd.exe // : , pack200.exe // : , policytool.exe // : , rmic.exe // : , rmid.exe // : , rmiregistry.exe // : , schemagen.exe // : , serialver.exe // : , servertool.exe // : , tnameserv.exe // : , unpack200.exe // : , wsgen.exe // : , wsimport.exe // : , xjc.exe File(s) ,, bytes Dir(s) ,,, bytes free F:\Java\JDK\bin>java -version java version "1.8.0_111" Java(TM) SE Runtime Environment (build 1.8.0_111-b14) Java HotSpot(TM) -Bit Server VM (build 25.111-b14, mixed mode) F:\Java\JDK\bin>javac Usage: javac <options> <source files> where possible options include: -g Generate all debugging info -g:none Generate no debugging info -g:{lines,vars,source} Generate only some debugging info -nowarn Generate no warnings -verbose Output messages about what the compiler is doing -deprecation Output source locations where deprecated APIs are used -classpath <path> Specify where to find user class files and annotation processors -cp <path> Specify where to find user class files and annotation processors -sourcepath <path> Specify where to find input source files -bootclasspath <path> Override location of bootstrap class files -extdirs <dirs> Override location of installed extensions -endorseddirs <dirs> Override location of endorsed standards path -proc:{none,only} Control whether annotation processing and/or compilation is done. -processor <class1>[,<class2>,<class3>...] Names of the annotation processors to run; bypasses default discovery process -processorpath <path> Specify where to find annotation processors -parameters Generate metadata for reflection on method parameters -d <directory> Specify where to place generated class files -s <directory> Specify where to place generated source files -h <directory> Specify where to place generated native header files -implicit:{none,class} Specify whether or not to generate class files for implicitly referenced files -encoding <encoding> Specify character encoding used by source files -source <release> Provide source compatibility with specified release
这样做比较麻烦,没次要用的时候,都需要到这个安装位置下来 我们需要添加安装的bin目录到系统环境变量中,
复制路径后,在系统环境变量中找到path,然后添加进去
之前安装的路径的JDK的bin路径就添加到系统环境变量中啦 F:\Java\JDK\bin
在cmd下验证一下,任意路径
C:\Windows\system32>java -version java version "1.8.0_111" Java(TM) SE Runtime Environment (build 1.8.0_111-b14) Java HotSpot(TM) -Bit Server VM (build 25.111-b14, mixed mode) C:\Windows\system32>E: E:\>java -version java version "1.8.0_111" Java(TM) SE Runtime Environment (build 1.8.0_111-b14) Java HotSpot(TM) -Bit Server VM (build 25.111-b14, mixed mode) E:\>javac Usage: javac <options> <source files> where possible options include: -g Generate all debugging info -g:none Generate no debugging info -g:{lines,vars,source} Generate only some debugging info -nowarn Generate no warnings -verbose Output messages about what the compiler is doing -deprecation Output source locations where deprecated APIs are used -classpath <path> Specify where to find user class files and annotation processors -cp <path> Specify where to find user class files and annotation processors -sourcepath <path> Specify where to find input source files -bootclasspath <path> Override location of bootstrap class files -extdirs <dirs> Override location of installed extensions -endorseddirs <dirs> Override location of endorsed standards path -proc:{none,only} Control whether annotation processing and/or compilation is done. -processor <class1>[,<class2>,<class3>...] Names of the annotation processors to run; bypasses default discovery process -processorpath <path> Specify where to find annotation processors -parameters Generate metadata for reflection on method parameters -d <directory> Specify where to place generated class files -s <directory> Specify where to place generated source files -h <directory> Specify where to place generated native header files -implicit:{none,class} Specify whether or not to generate class files for implicitly referenced files -encoding <encoding> Specify character encoding used by source files -source <release> Provide source compatibility with specified release -target <release> Generate class files for specific VM version -profile <profile> Check that API used is available in the specified profile -version Version information -help Print a synopsis of standard options -Akey[=value] Options to pass to annotation processors -X Print a synopsis of nonstandard options -J<flag> Pass <flag> directly to the runtime system -Werror Terminate compilation if warnings occur @<filename> Read options and filenames from file
四、编写hello world程序运行一下, 创建文件HelloWorld.java, 文件名字与类名对应,文件类型.java
public class HelloWorld{ public static void main(String[] args) { System.out.println("Hello World"); } }
cd到helloworld.java路径下
E:\Java>dir Volume in drive E has no label. Volume Serial Number is 35EE-5207 Directory of E:\Java 2017/01/14 12:49 <DIR> . 2017/01/14 12:49 <DIR> .. 2017/01/14 12:49 130 HelloWorld.java 2016/07/12 09:18 <DIR> httpcomponents-client-4.5.2 2016/07/12 09:17 3,047,752 httpcomponents-client-4.5.2-bin.zip 2016/07/12 08:59 1,643,553 httpcomponents-client-4.5.2-src.zip 2015/12/14 08:35 <DIR> sqljdbc_4.2 3 File(s) 4,691,435 bytes 4 Dir(s) 40,363,429,888 bytes free E:\Java>javac HelloWorld error: Class names, 'HelloWorld', are only accepted if annotation processing is explicitly requested 1 error E:\Java>javac HelloWorld.java E:\Java>java HelloWorld Hello World