一般我们在做网站开发的时候都会遇到前台表单的验证,以及远程验证:类似于注册的用户名是否被占用,下面贴出个人在学习过程中编写的例子:
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
首页
struts。xml配置:
后台远程验证:
package com.shop.action;
import java.io.ByteArrayInputStream;
import java.io.InputStream;
import org.springframework.context.annotation.Scope;
import org.springframework.stereotype.Controller;
import com.sun.xml.internal.messaging.saaj.util.ByteInputStream;
@Controller("registerDemo")
@Scope("prototype")
public class RegisterDemo {
private InputStream inputStream;
private String username;
public InputStream getInputStream() {
return inputStream;
}
public void setInputStream(InputStream inputStream) {
this.inputStream = inputStream;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String ajaxDemo(){
if(username.equals("admin")){
System.out.println(username);
inputStream=new ByteArrayInputStream("false".getBytes());
}else{
System.out.println(username);
inputStream=new ByteArrayInputStream("true".getBytes());
}
return "stream";
}
}

如何制定错误消息的显示位置以及远程验证成功后的结果显示,下面用一个完整的例子来显示。
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
首页