jsp javabean怎么没有办法用类定义的方法呢？

Question

创建一个随机以IP地址，时间等命名的字符串，但是里面setIPTimeStmap的方法却一直报错，但是使用getIPTimeRand()却可以得到正确的结果（只是没有IP地址）。是什么原因呢？

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Random;

public class IPTimeStamp {

 private SimpleDateFormat sdf = null;
 private String ip = null;


 public IPTimeStamp(String ip) {
     super();

     this.ip = ip;
 }


 public IPTimeStamp() {
     super();
 }

 public void setIpTimeStamp(String ip){
     this.ip = ip;

 }
   public String getIPTimeRand(){
     StringBuffer buf = new StringBuffer();
     if(this.ip != null){
         String s[] = this.ip.split("\\.");//根据ip以点分割将IP中的数字提取
         for(int i = 0 ; i < s.length; i++){
             buf.append(this.addZero(s[i], 3));//不够三位数的补零
         }
     }
     buf.append(this.getTimeStamp());
     Random r = new Random();//再在结尾加上三个随机数
     for(int i = 0 ; i < 3 ; i++ ){
         buf.append(r.nextInt(10));
     }
     return buf.toString();
 }


    也就是说，已经正确引入了javabean，可以正确使用，但是就是不能SET IP。

Answer 1

补充一下JSP页面的

<%@ page contentType="text/html; charset=GBK"
import="java.util.*,com.jspsmart.upload.*"%>
<%@ page import="inhome.IPTimeStamp" %>

。。。。

String ip = request.getHeader("x-forwarded-for");
if(null == ip || 0 == ip.length() || "unknown".equalsIgnoreCase(ip)) {
    ip = request.getHeader("Proxy-Client-IP");
}
if(null == ip || 0 == ip.length() || "unknown".equalsIgnoreCase(ip)) {
    ip = request.getHeader("WL-Proxy-Client-IP");
}
if(null == ip || 0 == ip.length() || "unknown".equalsIgnoreCase(ip)) {
    ip = request.getHeader("X-Real-IP");
}
if(null == ip || 0 == ip.length() || "unknown".equalsIgnoreCase(ip)) {
    ip = request.getRemoteAddr();
}

out.println("文件来自于 ip:"+ip);

getIpName.setIPTimeStmap(ip); //只要没有这句，就不会报错

out.println(getIpName.getIPTimeRand()); //没有上面一句，这里能得到正确的结果。