TA的每日心情 | 开心 2021-3-12 23:18 |
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签到天数: 2 天 [LV.1]初来乍到
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安装java2平台专业版5.0
下载最新版:
先进入http://java.sun.com/j2se/1.5.0/download.jsp,然后找到链接 Download JDK 5.0 Update 4 并进入。这里我选择了windows版的离线安装版 jdk-1_5_0_04-windows-i586-p.exe 。我的机子是XP。
一、双击安装执行文件jdk-1_5_0_04-windows-i586-p.exe,选择安装目录为d:jdk1.5,一路按next完成安装。
二、设置环境变量path和classpath。注意d:java是我的工作目录,在这个目录中编译和运行java程序。
在XP的桌面上,右击我的电脑》属性》在系统属性窗口中选高级》环境变量》在系统变量中编辑或新建变量:
JAVA_HOME=d:jdk1.5
path=d:jdk1.5in
classpath=d:jdk1.5lib;d:java
三、好了,开始测试,打开XP的DOS命令行,进入工作目录d:java,输入命令java -verdion,如下所示:
D:java>java -version
java version "1.5.0_04"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_04-b05)
Java HotSpot(TM) Client VM (build 1.5.0_04-b05, mixed mode, sharing)
以上输出说明安装成功!!!
四、再找几个网上现存的例子试试
1、从xml文件中装载属性,sampleprops.xml文件如下:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE properties SYSTEM
"http://java.sun.com/dtd/properties.dtd">
<properties>
<comment>Hi</comment>
<entry key="foo">bar</entry>
<entry key="fu">baz</entry>
</properties>
装载属性的java程序:
import java.util.*;
import java.io.*;
public class LoadSampleXML {
public static void main(String args[]) throws Exception {
Properties prop = new Properties();
FileInputStream fis = new FileInputStream("sampleprops.xml");
prop.loadFromXML(fis);
prop.list(System.out);
System.out.println("
The foo property: " + prop.getProperty("foo"));
}
}
程序运行结果:
D:java>java LoadSampleXML
-- listing properties --
fu=baz
foo=bar
The foo property: bar
D:java>
2、for/in循环
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
public class ForInDemo {
public static void main(String[] args) {
List wordlist = new ArrayList();
Set wordset = new HashSet();
System.out.println("Assigning arguments to lists...");
for (String word : args) {
System.out.print(word + " ");
wordlist.add(word);
wordset.add(word);
}
System.out.println();
System.out.println("Printing words from wordlist " +"(ordered, with duplicates)...");
for (Object word : wordlist) {
System.out.print((String)word + " ");
}
System.out.println();
System.out.println("Printing words from wordset " +"(unordered, no duplicates)...");
for (Object word : wordset) {
System.out.print((String)word + " ");
}
}
}
运行结果:
D:java>java ForInDemo 333 4444 555
Assigning arguments to lists...
333 4444 555
Printing words from wordlist (ordered, with duplicates)...
333 4444 555
Printing words from wordset (unordered, no duplicates)...
555 333 4444
D:java>
3、泛型支持
import java.util.*;
public class UseGeneric{
public static void main(String[] args){
Vector<Integer> vi = new Vector<Integer>();
vi.add(new Integer(24));
vi.add(35);
for(Integer i : vi){
System.out.println(i);
}
}
}
运行结果:
D:java>java UseGeneric
24
35
D:java>
4、枚举类型
import java.util.EnumSet;
public class Demo {
enum Day { SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY }
public static void main(String[] args) {
Demo demo=new Demo();
demo.Test1();
}
public void Test1(){
for (Day d : EnumSet.range(Day.MONDAY, Day.FRIDAY))
System.out.println(d);
}
}
运行结果:
D:java>java Demo
MONDAY
TUESDAY
WEDNESDAY
THURSDAY
FRIDAY
D:java>
源码下载:http://203.93.208.26/kj/cwb/dir4/dir4a/jdk1.5test.zip |
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