Java开发网 - 字符串处理问题！

Topic: 字符串处理问题！

1.字符串处理问题！

Posted by: handsome112233
Posted on: 2006-05-26 10:11

我想实现输入“1234567”，输出为“$1,234,567”
下边是我写的程序：
import java.lang.*;

class ZhuangHuan{

public StringBuffer Zh(StringBuffer buffer){

StringBuffer str=buffer.reverse();

str.append("$");

for(int i=0;i<buffer.length();i++){

i=i+3;
str.insert(i,",");

}

str.reverse();
return str;
}
public static void main(String [] args){
ZhuangHuan z=new ZhuangHuan();
StringBuffer b=new StringBuffer("1234567");
System.out.println("zhuang huan huo:"+z.Zh(b));
}

}

运行时出错，信息如下：
Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String ind
ex out of range: 11
at java.lang.AbstractStringBuilder.insert(AbstractStringBuilder.java:980
)
at java.lang.StringBuffer.insert(StringBuffer.java:447)
at ZhuangHuan.Zh(ZhuangHuan.java:17)
at ZhuangHuan.main(ZhuangHuan.java:33)

请各位帮帮忙！谢谢！

2.Re:字符串处理问题！ [Re: handsome112233]

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Posted by: JavaandC
Posted on: 2006-05-26 11:32

我从新给你写了一个，可以实现你的功能，你看一下吧。

import java.text.DecimalFormat;

public class FormatNumber{

public String Format(String str) {

double insert = Double.parseDouble(str);

DecimalFormat df = new DecimalFormat("$0,000,000");

return df.format(insert);
}

public static void main(String [] args) {

FormatNumber f = new FormatNumber();

String str= "1234567";

System.out.println("Message:"+f.Format(str));

}
}

输出结果：
Message : $1,234,567

3.Re:字符串处理问题！ [Re: handsome112233]	Copy to clipboard
Posted by: handsome112233 Posted on: 2006-05-26 13:25 谢谢JavaandC，可以解释一下您的程序吗？

4.Re:字符串处理问题！ [Re: handsome112233]	Copy to clipboard
Posted by: handsome112233 Posted on: 2006-05-26 13:30 还有一个问题想请教！如果要从控制台读入字符应该怎样做！ System.in.read();只能读入一个字节！

5.Re:字符串处理问题！ [Re: handsome112233]

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Posted by: handsome112233
Posted on: 2006-05-26 14:33

我将你的程度作了如下修改，但是出现问题，不知如何解决！
import java.text.DecimalFormat;
import java.io.*;
public class FormatNumber{

public String Format(String str) {

double insert = Double.parseDouble(str);

DecimalFormat df = new DecimalFormat("$0,000,000,000");

return df.format(insert);
}

public static void main(String [] args) {

FormatNumber f = new FormatNumber();

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

String str=br.readLine();
System.out.println("Message:"+f.Format(str));

}
}
出现编译时出现如下问题：
D:\JCreator\MyProjects\FormatNumber.java:24: 未报告的异常 java.io.IOException；必须对其进行捕捉或声明以便抛出
String str=br.readLine();
^
1 错误

6.Re:字符串处理问题！ [Re: handsome112233]

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Posted by: JavaandC
Posted on: 2006-05-26 14:50

给你的main方法改成

public static void main(String [] args) {

FormatNumber f = new FormatNumber();

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

String str = null;
try {
  str = br.readLine(); //这句要捕获异常的IOException

} catch (IOException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
}
System.out.println("Message:"+f.Format(str));

}

7.Re:字符串处理问题！ [Re: handsome112233]

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Posted by: handsome112233
Posted on: 2006-05-26 14:51

知道了怎样做了！原来要throw IOException!
正确的程序如下！
import java.text.DecimalFormat;
import java.io.*;

public class FormatNumber{

public String Format(String str) {

double insert = Double.parseDouble(str);

DecimalFormat df = new DecimalFormat("$0,000,000,000");

return df.format(insert);
}

public String printConsoleLine() throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String str = null;

str = br.readLine();
return str;

}

public static void main(String [] args)throws IOException {

FormatNumber f = new FormatNumber();

String str=f.printConsoleLine();

//String str= "1234567899";

System.out.println("Message:"+f.Format(str));

}
}

8.Re:字符串处理问题！ [Re: handsome112233]	Copy to clipboard
Posted by: JavaandC Posted on: 2006-05-26 14:55 最好不要把异常抛给虚拟机，要自己捕获异常，我已经把代码发在上面了，你自己看一下吧。

9.Re:字符串处理问题！ [Re: handsome112233]

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Posted by: handsome112233
Posted on: 2006-05-26 14:56

public static void main(String [] args) {

FormatNumber f = new FormatNumber();

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

String str = null;
try {
str = br.readLine();

} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("Message:"+f.Format(str));

}

楼主的方法不行，因为我看到报错后也是这样做的。