用 JSP 在客户端生成 JavaScript 代码来实现表单校验
●○●○●○●○●○●○●○●○●○●○●○●○●○●○ ○ 作者:刘湛 日期:2000-01-05 jeru@163.net ● ● http://www.cyberlabs.com/~jeru/ ○ ○ 欢迎访问爪哇人,获取更多资料 ● ●○●○●○●○●○●○●○●○●○●○●○●○●○●○
今天费了一天时间就是做这个东西,原理很简单,就是用 JSP 在页面的开始部分生成一段代码, 如 errorcheck.jsp 中所示,但程序太长,还是费了我不少时间来改写。
主程序是名为 ErrorCheck.java ,有了这个 ErrorCheck 的 Bean,我们就再也不用为了表单校验去 写那一大堆烦人的 JavaScript 代码了。ErrorCheck 类已帮我们生成了几乎所有你将会用到的校验方法, 如是否为数字,长度的校验,是否为合法email等,你只需在 jsp 页面里调用相应的函数就可以了。
目前一共有七个函数:
一 检测是否为数字 //输入输入框名和错误提示信息 numericCheck(String inputName,String errorMsg);
二 检测email是否合法 //输入输入框名和错误提示信息 emailCheck(String inputName,String errorMsg);
三 检测电话号码是否合法 //输入输入框名和错误提示信息 telCheck(String inputName,String errorMsg);
四 检测字串长度是否在规定范围那内 //输入输入框名,错误提示信息,最小长度,最大长度 lengthCheck(String inputName,String errorMsg,int min,int max);
五 检测字串中是否不含禁止的字串 //输入输入框名,错误提示信息,禁止字串 denyStrCheck(String inputName,String errorMsg,String str);
六 检测字串中是否含给定字串 //输入输入框名,错误提示信息,指定字串 stringCheck(String inputName,String errorMsg,String str);
七 检测日期格式是否为 "yyyy-mm-dd" //输入输入框名和错误提示信息 dateCheck(String inputName,String errorMsg);
只要调用一下这个bean,然后用setFromName()设定你的表单名,再调用以上函数, 最后 out.println(yourID.ErrorCheckScript()),就输出了一段 JavaScript 代码了,当然了, 别忘了这个 <form name=myForm onsubmit="return errorCheck();">
ok,just enjoy it,今天太累,不想多少,有任何意见请写信给我或在我主页上留言。
注:我调试 errorcheck.jsp 的时候因服务器的问题不知为何不能用 usebean,setProperty 的方法, 只好 new 了一下,我想你们是应该可以用useBean和setProperty的,自己改一下吧。
===================================== errorcheck.jsp =====================================
<%@ page language="java" import="dbclass.*" %> <%@ page contentType="text/html; charset=gb2312" %> <jsp:useBean id="cc" scope="page" class="dbclass.ErrorCheck" />
<% ErrorCheck ec = new ErrorCheck(); ec.setFormName("myForm"); ec.numericCheck("number","The Number you input is invalid!"); ec.emailCheck("email","The Email you input is invalid!"); ec.telCheck("tel","The telephone you input is invalid!"); ec.lengthCheck("strlen","The string you input in the fourth field in not between 6-8",6,8); ec.denyStrCheck("nojeru","The fifith field must not contain 'jeru'","jeru"); ec.stringCheck("jeru","The sixth field must not null and contian 'jeru'","jeru"); ec.dateCheck("date","The date you input is invalid,should be yyyy-mm-dd"); out.println(ec.ErrorCheckScript()); %>
<html> <body style="font-size:9pt; font-family:Arial;"> <h1>Errocheck Test</h1> <hr> <form name=myForm onsubmit="return errorCheck();">
input a number:<br> <input type="text" name="number"><p>
input a emial:<br> <input type="text" name="email"><p>
input a telephone:<br> <input type="text" name="tel"><p>
input a string (length should between 6-8):<br> <input type="text" name="strlen"><p>
input a string (shoulde not contain "jeru"):<br> <input type="text" name="nojeru"><p>
input a string (must contain "jeru"):<br> <input type="text" name="jeru"><p>
input a date (yyyy-mm-dd):<br> <input type="text" name="date"><p>
<br><input type="submit" name="submit" value="go"> </form> </body> </html>
===================================== ErrorCheck.java =====================================
package dbclass; /** * ErrorCheck v 1.0 * * 这个类是用来在客户端生成 JavaScript 代码来校验表单的 * 原是版本是同事 Macro 用 PHP 写的,我感觉十分好用,再也 * 不用再为那些表单区写烦人的 javascript 代码拉,感谢他! * 这次我用 Java 改写,封装成一个类,并修复了少许的 bug,加 * 多了一条校验的功能,它的扩展性很好,以后可能会继续完善。 * * Mender : * Jeru Liu * Homepage : * http://www.cyberlabs.com/~jeru/ * Email: jeru@163.net * */
import java.io.*;
public class ErrorCheck{
/* public: the javascript string */ String errorCheckStr;
/* public: the form name you used */ public String formName;
public void setFormName(String formName) { this.formName = formName; }
/***************************************************************************\ *public: constructor functions *构造函数 \***************************************************************************/ public ErrorCheck(){ this.errorCheckStr = "<script ID=clientEventHandlersJS language=javascript>" + "\n" + "<!--" + "\n"; this.neededFunction();// load the needed functions this.errorCheckStr += "function errorCheck() {" + "\n"; }
/***************************************************************************\ *public: export javascript script *输出 JAVASCRIPT 脚本 \***************************************************************************/ public String ErrorCheckScript(){ this.errorCheckStr += "}" + "\n" + "-->" + "\n" + "</script>" + "\n"; return this.errorCheckStr; }
/***************************************************************************\ *public: check the numeric *检查录入框值是否是数字 \***************************************************************************/ public void numericCheck(String inputName, String errorMsg){ this.errorCheckStr += "if(fucCheckNUM(document."+formName+"."+inputName+".value) == 0) {" + "\n" + "alert(\""+errorMsg+".\");" + "\n" + "document."+formName+"."+inputName+".focus();" + "\n" + "return(false);" + "\n" + "}" + "\n\n"; }
/***************************************************************************\ *public: check the length *检查录入框值的长度 \***************************************************************************/ public void lengthCheck(String inputName, String errorMsg, int MinLength, int MaxLength) { this.errorCheckStr += "if(fucCheckLength(document."+formName+"."+inputName+".value)<"+MinLength+" || " + "\n" + "fucCheckLength(document."+formName+"."+inputName+".value)>"+MaxLength+") {" + "\n" + "alert(\""+errorMsg+".\");" + "\n" + "document."+formName+"."+inputName+".focus();" + "\n" + "return(false);" + "\n" + "}" + "\n\n"; }
/***************************************************************************\ *public: check the email *检查录入框值是否是正确的EMAIL格式 \***************************************************************************/ public void emailCheck(String inputName, String errorMsg){ this.errorCheckStr += "if(chkemail(document."+formName+"."+inputName+".value) == 0) {" + "\n" + "alert(\""+errorMsg+".\");" + "\n" + "document."+formName+"."+inputName+".focus();" + "\n" + "return(false);" + "\n" + "}" + "\n\n"; }
/***************************************************************************\ *public: check the telephone number *检查录入框值是否是电话号码 \***************************************************************************/ public void telCheck(String inputName, String errorMsg){ this.errorCheckStr += "if(fucCheckTEL(document."+formName+"."+inputName+".value) == 0) {" + "\n" + "alert(\""+errorMsg+".\");" + "\n" + "document."+formName+"."+inputName+".focus();" + "\n" + "return(false);" + "\n" + "}" + "\n\n"; }
/***************************************************************************\ *public: check if the input value contian the prefered string *检查录入框值是否是包含给定字串 \***************************************************************************/ public void stringCheck(String inputName, String errorMsg, String string){ this.errorCheckStr += "if(document."+formName+"."+inputName+".value.indexOf(\""+string+"\") != 0) {" + "\n" + "alert(\""+errorMsg+".\");" + "\n" + "document."+formName+"."+inputName+".focus();" + "\n" + "return(false);" + "\n" + "}" + "\n\n"; }
/***************************************************************************\ *public: check if the input value contain the denyed string *检查录入框值是否是包含给禁止的字串 \***************************************************************************/ public void denyStrCheck(String inputName, String errorMsg, String string){ this.errorCheckStr += "if (document."+formName+"."+inputName+".value.length == 0 || " + "\n" + "document."+formName+"."+inputName+".value.indexOf(\""+string+"\") != -1) {" + "\n" + "alert(\""+errorMsg+".\");" + "\n" + "document."+formName+"."+inputName+".focus();" + "\n" + "return(false);" + "\n" + "}" + "\n\n"; }
/***************************************************************************\ *public: check the YYYY-MM-DD format date *检查录入框值是否是YYYY-MM-DD的日期格式 \***************************************************************************/ public void dateCheck(String inputName, String errorMsg){ this.errorCheckStr += "if(chkdate(document."+formName+"."+inputName+".value) == 0) {" + "\n" + "alert(\""+errorMsg+".\");" + "\n" + "document."+formName+"."+inputName+".focus();" + "\n" + "return(false);" + "\n" + "}" + "\n\n"; }
public void neededFunction(){ this.errorCheckStr += "//函数名:fucCheckNUM" + "\n" + "//功能介绍:检查是否为数字" + "\n" + "//参数说明:要检查的数字" + "\n" + "//返回值:1为是数字,0为不是数字" + "\n" + "function fucCheckNUM(NUM) {" + "\n" + "var i,j,strTemp;" + "\n" + "strTemp=\"0123456789\";" + "\n" + "if ( NUM.length == 0) return 0;" + "\n" + "for (i=0;i<NUM.length;i++){" + "\n" + "j = strTemp.indexOf(NUM.charAt(i));" + "\n" + "if (j==-1) {" + "\n" + "//说明有字符不是数字" + "\n" + "return 0;" + "\n" + "}" + "\n" + "}" + "\n" + "//说明是数字" + "\n" + "return 1;" + "\n" + "}" + "\n\n" +
"//函数名:fucCheckLength" + "\n" + "//功能介绍:检查字符串的长度" + "\n" + "//参数说明:要检查的字符串" + "\n" + "//返回值:长度值" + "\n" + "function fucCheckLength(strTemp) {" + "\n" + "var i,sum;" + "\n" + "sum=0;" + "\n" + "for(i=0;i<strTemp.length;i++) {" + "\n" + "if ((strTemp.charCodeAt(i)>=0) && (strTemp.charCodeAt(i)<=255))" + "\n" + "sum=sum+1;" + "\n" + "else" + "\n" + "sum=sum+2;" + "\n" + "}" + "\n" + "return sum;" + "\n" + "}" + "\n\n" +
"//函数名:chkemail" + "\n" + "//功能介绍:检查是否为Email Address" + "\n" + "//参数说明:要检查的字符串" + "\n" + "//返回值:0:不是1:是" + "\n" + "function chkemail(a){" + "\n" + "var i=a.length;" + "\n" + "var temp = a.indexOf('@');" + "\n" + "var tempd = a.indexOf('.');" + "\n" + "if (temp > 1) {" + "\n" + "if ((i-temp) > 3) {" + "\n" + "if (tempd!=-1) {" + "\n" + "return 1;" + "\n" + "}" + "\n" + "}" + "\n" + "}" + "\n" + "return 0;" + "\n" + "}" + "\n\n" +
"//函数名:fucCheckTEL" + "\n" + "//功能介绍:检查是否为电话号码" + "\n" + "//参数说明:要检查的字符串" + "\n" + "//返回值:1为是合法,0为不合法" + "\n" + "function fucCheckTEL(TEL) {" + "\n" + "var i,j,strTemp;" + "\n" + "strTemp=\"0123456789-()#\";" + "\n" + "if (TEL.length == 0) return 0;" + "\n" + "for (i=0;i<TEL.length;i++) {" + "\n" + "j=strTemp.indexOf(TEL.charAt(i));" + "\n" + "if (j==-1) {" + "\n" + "//说明有字符不合法" + "\n" + "return 0;" + "\n" + "}" + "\n" + "}" + "\n" + "//说明合法" + "\n" + "return 1;" + "\n" + "}" + "\n\n" +
"//函数名:chkdate(YYYY-MM-DD)" + "\n" + "//功能介绍:检查是否为日期" + "\n" + "//参数说明:要检查的字符串" + "\n" + "//返回值:0:不是日期1:是日期" + "\n" + "function chkdate(datestr) {" + "\n" + "var lthdatestr" + "\n" + "if (datestr != \"\")" + "\n" + "lthdatestr= datestr.length ;" + "\n" + "else" + "\n" + "lthdatestr=0;" + "\n" + "var tmpy=\"\";" + "\n" + "var tmpm=\"\";" + "\n" + "var tmpd=\"\";" + "\n" + "//var datestr;" + "\n" + "var status;" + "\n" + "status=0;" + "\n" + "if ( lthdatestr== 0)" + "\n" + "return 0;" + "\n" + "for (i=0;i<lthdatestr;i++) {" + "\n" + "if (datestr.charAt(i)== '-') {" + "\n" + "status++;" + "\n" + "}" + "\n" + "if (status>2) {" + "\n" + "return 0;" + "\n" + "}" + "\n" + "if ((status==0) && (datestr.charAt(i)!='-')) {" + "\n" + "tmpy=tmpy+datestr.charAt(i)" + "\n" + "}" + "\n" + "if ((status==1) && (datestr.charAt(i)!='-')) {" + "\n" + "tmpm=tmpm+datestr.charAt(i)" + "\n" + "}" + "\n" + "if ((status==2) && (datestr.charAt(i)!='-')) {" + "\n" + "tmpd=tmpd+datestr.charAt(i)" + "\n" + "}" + "\n" + "}" + "\n" + "year=new String (tmpy);" + "\n" + "month=new String (tmpm);" + "\n" + "day=new String (tmpd)" + "\n" + "if ((tmpy.length!=4) || (tmpm.length>2) || (tmpd.length>2)) {" + "\n" + "return 0;" + "\n" + "}" + "\n" + "if (!((1<=month) && (12>=month) && (31>=day) && (1<=day)) ) {" + "\n" + "return 0;" + "\n" + "}" + "\n" + "if (!((year % 4)==0) && (month==2) && (day==29)) {" + "\n" + "return 0;" + "\n" + "}" + "\n" + "if ((month<=7) && ((month % 2)==0) && (day>=31)) {" + "\n" + "return 0;" + "\n" + "}" + "\n" + "if ((month>=8) && ((month % 2)==1) && (day>=31)) {" + "\n" + "return 0;" + "\n" + "}" + "\n" + "if ((month==2) && (day==30)) {" + "\n" + "return 0;" + "\n" + "}" + "\n" + "return 1;" + "\n" + "}" + "\n\n";
}
/*public static void main(String[] args) { ErrorCheck ec = new ErrorCheck("testFrom"); String script = ec.ErrorCheckScript(); System.out.println(script); } */
}
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