如何使用PHP和jQuery在上传过程中更改图像名称

我正在使用这个PHP代码在服务器上上传图像，但我想添加我的图像名称。一切正常，但需要帮助才能更改图像名称。等待回复。谢谢

<?php
if(isset($_FILES["file"]["type"]))
{
$validextensions = array("jpeg", "gif", "jpg", "png");
$temporary = explode(".", $_FILES["file"]["name"]);
$file_extension = end($temporary);
if ((($_FILES["file"]["type"] == "image/png")|| ($_FILES["file"]["type"] == "image/gif") || ($_FILES["file"]["type"] == "image/jpg") || ($_FILES["file"]["type"] == "image/jpeg")
) && ($_FILES["file"]["size"] < 200000)//Approx. 100kb files can be uploaded.
&& in_array($file_extension, $validextensions)) {
if ($_FILES["file"]["error"] > 0)
{
echo "Return Code: " . $_FILES["file"]["error"] . "<br/><br/>";
}
else
{
if (file_exists("test/" . $_FILES["file"]["name"])) {
echo $_FILES["file"]["name"] . " <span id='invalid'><b>already exists.</b></span> ";
}
else
{
$sourcePath = $_FILES['file']['tmp_name']; // Storing source path of the file in a variable
$targetPath = "test/".$_FILES['file']['name']; // Target path where file is to be stored
move_uploaded_file($sourcePath,$targetPath) ; // Moving Uploaded file
echo "<span id='success'>Image Uploaded Successfully...!!</span><br/>";
echo "<br/><b>File Name:</b> " . $_FILES["file"]["name"] . "<br>";
echo "<b>Type:</b> " . $_FILES["file"]["type"] . "<br>";
echo "<b>Size:</b> " . ($_FILES["file"]["size"] / 1024) . " kB<br>";
echo "<b>Temp file:</b> " . $_FILES["file"]["tmp_name"] . "<br>";
}
}
}
else
{
echo "<span id='invalid'>***Invalid file Size or Type***<span>";
}
}
?>

这也是我的JS编码

    $(document).ready(function (e) {
$("#uploadimage").on('submit',(function(e) {
e.preventDefault();
$("#message").empty();
$('#loading').show();
$.ajax({
url: "ajax_php_file.php", // Url to which the request is send
type: "POST",             // Type of request to be send, called as method
data: new FormData(this), // Data sent to server, a set of key/value pairs (i.e. form fields and values)
contentType: false,       // The content type used when sending data to the server.
cache: false,             // To unable request pages to be cached
processData:false,        // To send DOMDocument or non processed data file it is set to false
success: function(data)   // A function to be called if request succeeds
{
$('#loading').hide();
$("#message").html(data);
}
});
}));
// Function to preview image after validation
$(function() {
$("#file").change(function() {
$("#message").empty(); // To remove the previous error message
var file = this.files[0];
var imagefile = file.type;
var match= ["image/jpeg","image/gif","image/png","image/jpg"];
if(!((imagefile==match[0]) || (imagefile==match[1]) || (imagefile==match[2])))
{
$('#previewing').attr('src','noimage.png');
$("#message").html("<p id='error'>Please Select A valid Image File</p>"+"<h4>Note</h4>"+"<span id='error_message'>Only jpeg, jpg and png Images type allowed</span>");
return false;
}
else
{
var reader = new FileReader();
reader.onload = imageIsLoaded;
reader.readAsDataURL(this.files[0]);
}
});
});
function imageIsLoaded(e) {
$("#file").css("color","green");
$('#image_preview').css("display", "block");
$('#previewing').attr('src', e.target.result);
$('#previewing').attr('width', '250px');
$('#previewing').attr('height', '230px');
};
});