和大多數人一樣，我平時撰寫JAVA程式時，都是透過eclipse來編譯並執行。
但如果我只是想小幅修改並執行一支簡單的程式，實在不想勞師動眾去開啟eclipse呢？
或者需要在沒有eclipse的電腦上執行，但實在不想為了一支小程式再去下載佈署eclipse？
其實只要稍稍修改一下JAVA程式，再搭配bat指令即可做到，
當然，執行程式的電腦上必須有適當的JRE，這點我想不用多做說明。
以下以一個從Yahoo!奇摩股市抓特定股票股價的程式為例，說明如何低調的關心投資標的的股價。
JAVA程式：stock.java
我是先在eclipse寫好後，去workspace把java檔另存一份，
然後打開另存的java檔，把第一行的package xxx拿掉，就變成這樣：
import java.io.BufferedReader;
import java.io.File;
import java.io.FileWriter;
import java.io.InputStreamReader;
import java.net.URL;
public class stock {
public static void main(String[] args) {
try{
String[] CodeStr = {"0050","2330","2498"};//鍵入股票代號，支數不限
String theURL = "";
URL u;
BufferedReader theHtml;
String name = "";
String nowTime = "";
String Recommand = "";
String nowPrice = "";
String nowBuyPrice = "";
String nowSellPrice = "";
String nowChange = "";
String nowDiffRate = "";
String nowQuantities = "";
String yesterdayPrice = "";
String opening = "";
String high = "";
String low = "";
for(int z = 0 ; z < 6000 ; z++){//執行次數只要可以cover開盤到收盤的時間即可
System.out.println("代號\t時間\t成交價\t買價\t賣價\t漲跌\t漲跌幅\t成交量\t昨收\t開盤\t最高\t最低");
for(int Code = 0 ; Code < CodeStr.length ; Code++ ){
try{
theURL = "http://tw.stock.yahoo.com/q/q?s="+CodeStr[Code];
u = new URL(theURL);
theHtml = new BufferedReader(new InputStreamReader(u.openStream()));
String theWholePackage = "";
while((theURL = theHtml.readLine())!=null){
theWholePackage = theWholePackage + theURL+"\n";
}
int s = theWholePackage.indexOf("href=\"/q/bc?s="+CodeStr[Code]+"\">");
int t =
theWholePackage.indexOf("</a><br><a
href=\"/pf/pfsel?stocklist="+CodeStr[Code]+";\"><font
size=-1>");
name = theWholePackage.substring(s+20,t);
s = theWholePackage.indexOf("<td align=\"center\" bgcolor=\"#FFFfff\" nowrap>");
theWholePackage = theWholePackage.substring(s+44);
nowTime = theWholePackage.substring(0,5);
s = theWholePackage.indexOf("<td align=\"center\" bgcolor=\"#FFFfff\" nowrap>");
t = theWholePackage.indexOf("</b></td>");
nowPrice = theWholePackage.substring(s+47,t);
theWholePackage = theWholePackage.substring(t+8);
s = theWholePackage.indexOf("<td align=\"center\" bgcolor=\"#FFFfff\" nowrap>");
t = theWholePackage.indexOf("</td>");
nowBuyPrice = theWholePackage.substring(s+44,t);
theWholePackage = theWholePackage.substring(t+4);
s = theWholePackage.indexOf("<td align=\"center\" bgcolor=\"#FFFfff\" nowrap>");
t = theWholePackage.indexOf("</td>");
nowSellPrice = theWholePackage.substring(s+44,t);
theWholePackage = theWholePackage.substring(t+4);
s = theWholePackage.indexOf("<td align=\"center\"
bgcolor=\"#FFFfff\" nowrap><font color=#009900>");
theWholePackage = theWholePackage.substring(s+83);
t = theWholePackage.indexOf("<td align=\"center\" bgcolor=\"#FFFfff\" nowrap>");
theWholePackage = theWholePackage.substring(t);
s = theWholePackage.indexOf("<td align=\"center\" bgcolor=\"#FFFfff\" nowrap>");
t = theWholePackage.indexOf("</td>");
nowQuantities = theWholePackage.substring(s+44,t);
theWholePackage = theWholePackage.substring(t+4);
s = theWholePackage.indexOf("<td align=\"center\" bgcolor=\"#FFFfff\" nowrap>");
t = theWholePackage.indexOf("</td>");
yesterdayPrice = theWholePackage.substring(s+44,t);
theWholePackage = theWholePackage.substring(t+4);
s = theWholePackage.indexOf("<td align=\"center\" bgcolor=\"#FFFfff\" nowrap>");
t = theWholePackage.indexOf("</td>");
opening = theWholePackage.substring(s+44,t);
theWholePackage = theWholePackage.substring(t+4);
s = theWholePackage.indexOf("<td align=\"center\" bgcolor=\"#FFFfff\" nowrap>");
t = theWholePackage.indexOf("</td>");
high = theWholePackage.substring(s+44,t);
theWholePackage = theWholePackage.substring(t+4);
s = theWholePackage.indexOf("<td align=\"center\" bgcolor=\"#FFFfff\" nowrap>");
t = theWholePackage.indexOf("</td>");
low = theWholePackage.substring(s+44,t);
theWholePackage = theWholePackage.substring(t+4);
double ch1 = Double.parseDouble(nowPrice);
double ch2 = Double.parseDouble(yesterdayPrice);
double ch = 0 ;
double chr = 0 ;
if(ch1 - ch2 >= 0)ch = ch1 - ch2 + 0.005 ;
else ch = ch1 - ch2 - 0.005 ;
ch = (int)(ch*1000)/10;
ch = ch/100;
chr = (ch*100)/ch2;
chr = (int)(chr*1000)/10;
chr = chr/100;
if(ch<0){
nowChange = "-"+String.valueOf(-ch);
nowDiffRate = "-"+String.valueOf(-chr)+"%";
}else{
nowChange = "+"+String.valueOf(ch);
nowDiffRate = "+"+String.valueOf(chr)+"%";
}
System.out.println(CodeStr[Code]+"\t"+nowTime+"\t"+nowPrice+"\t"+nowBuyPrice
+"\t"+nowSellPrice+"\t"+nowChange+"\t"+nowDiffRate+"\t"+nowQuantities+"\t"+yesterdayPrice
+"\t"+opening+"\t"+high+"\t"+low);
Thread.sleep(1000);//停一秒
}catch(java.io.FileNotFoundException e1){
System.out.println(e1);
Thread.sleep(1000);
continue;
}catch(java.lang.StringIndexOutOfBoundsException e2){
System.out.println(e2);
Thread.sleep(1000);
continue;
}
}
System.out.println();
Thread.sleep(1000);//停一秒
}
}catch(Exception e){
System.out.println(e.toString());
}
}
}適當的秒數暫停是為了避免畫面跳太快看不清楚，同時也表示對Yahoo!奇摩股市伺服器的尊重。
bat檔：stock.bat，bat的檔名可以隨便取，但前面java的檔名一定要和程式中的class名一樣，雖然是常識，但還是稍微提醒一下。
如下使用cmd指令把java檔先編譯後執行
@echo off
color 0E
javac stock.java
java -classpath . stock
pause
其中，color 0E是用來指定執行畫面的顏色，第一碼是底色，第二碼是字的顏色，可以用的顏色及代碼有：
0 = 黑色
1 = 藍色
2 = 綠色
3 = 藍綠色
4 = 紅色
5 = 紫色
6 = 黃色
7 = 白色
8 = 灰色
9 = 淡藍色
A = 淡綠色
B = 淡藍綠色
C = 淡紅色
D = 淡紫色
E = 淡黃色
F = 亮白色
可自行視狀況搭配低調而清楚的顏色
