var name = document.getElementById("username"); if(name.value.length >0) send_request("POST","/webapps/registerAction.do?method=checkname&name="+name.value,null,"TEXT",respondCheckName); else { //用户名为空..则不提交 return ; }
}
function respondCheckName() { if (http_request.readyState == 4) { if (http_request.status == 200) { var context = http_request.responseTEXT; if(context!=null) {
{
jdbcConnection();
try {
String sq="select username from zhuce where username='"+username+"'";
ResultSet rs=st.executeQuery(sq);
if(rs.next()){
System.out.println("用户名以存在");
return false;
}
String sql="insert into zhuce(username,password) values(?,?)";
pst=con.prepareStatement(sql);
pst.setString(1,chString(username));
pst.setString(2,chString(password));
pst.executeUpdate();
return true;
} catch (Exception e) {
e.printStackTrace();
System.out.println(e.getMessage());
}
return false;
}
http_request = false;
if(window.XMLHttpRequest) { //Mozilla
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType) {//MiME
http_request.overrideMimeType("text/xml");
}
}
else if (window.ActiveXObject) { // IE
try {
http_request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {}
}
}
if (!http_request) {
window.alert("XMLHttpRequest.");
return false;
}
if(responseType.toLowerCase()=="text") {
http_request.onreadystatechange = callback;
}
else if(responseType.toLowerCase()=="xml") {
http_request.onreadystatechange = callback;
}
else {
window.alert("");
return false;
}
// URL
if(method.toLowerCase()=="get") {
http_request.open(method, url, true);
}
else if(method.toLowerCase()=="post") {
http_request.open(method, url, true);
http_request.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
}
else {
window.alert("http");
return false;
}
http_request.send(content);
}
//验证用户名是否存在
function ValidatorName()
{
var name = document.getElementById("username");
if(name.value.length >0)
send_request("POST","/webapps/registerAction.do?method=checkname&name="+name.value,null,"TEXT",respondCheckName);
else
{
//用户名为空..则不提交
return ;
}
}
function respondCheckName()
{
if (http_request.readyState == 4)
{
if (http_request.status == 200)
{
var context = http_request.responseTEXT;
if(context!=null)
{
if(context.indexOf("true")==-1)
{ //存在 }
else
{ //不存在 }
}
}
}
}
Action代码:
PrintWriter out = response.getWriter();
String username = request.getParameter("name");
if(username==null)
{
out.write("false");
return null;
}
else
{
//查询数据库
out.write("true");
return null;
}