我编写了JButton代码，用于从MySQL数据库下载JTable上显示的选定文件。我希望它下载所有选定的文件。最初我能够一次下载一个文件。现在我已经编辑了代码，它什么都不做，并且没有返回任何错误。代码中可能有什么问题。
如何在我的代码中实现这一目标？
我的代码：
private void jButtonDownloadActionPerformed(java.awt.event.ActionEvent evt) {
int BUFFER_SIZE = 4096;
try {
int[] selected_rows= jTable1.getSelectedRows();
for (int i = 0; i < selected_rows.length; i++){
if (i < selected_rows.length - 1 ) {
String tableClick=(jTable1.getModel().getValueAt(selected_rows[i],i).toString());
Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/employee_certificate","root","");
String sql= "SELECT Cert, Cert_Name FROM certificate WHERE Cert_Code =?" ;
PreparedStatement pstmt = con.prepareStatement(sql);
pstmt.setString(1, tableClick);
ResultSet rs=pstmt.executeQuery();
if(rs.next()){
String filename = rs.getString("Cert_Name");
Blob blob = rs.getBlob("Cert");
InputStream inputStream = blob.getBinaryStream();
String filePath ="C:\\Users\\User\\Downloads\\Documents\\"+filename;
OutputStream outputStream = new FileOutputStream(filePath);
int bytesRead = -1;
byte[] buffer = new byte[BUFFER_SIZE];
while ((bytesRead = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
inputStream.close();
outputStream.close();
JOptionPane.showMessageDialog(null,"file saved to Documents in your C folder.");
}}} }
catch (Exception e)
{JOptionPane.showMessageDialog(null,e);}}
答案 0 :(得分：0)
最后我明白了。非常感谢@Thompson。我需要使用JTable.getSelectedRows（）而不是JTable.getSelectedRow（）然后循环数组，如下所示：
/* Nav Accordion Plugin v1.1.2
************************************/
(function($){
$.fn.navAccordion = function(options, callback){
this.each(function(){
//Options
var settings = $.extend({
expandButtonText : "+", //Text inside of expand button
collapseButtonText: "-", //Text inside of collapse button
selectedExpand: "true", //Expand the selected channel
selectedClass: "selected", //Class that will be used to detect the currently selected channel - this will check the "parentElement" for this class (the parent <li> by default)
multipleLevels: "true", //Apply accordion to all levels - setting this to false will apply the accordion only to the first level
buttonWidth: "20%", //Width of accordion expand/collapse button as a percentage or pixels
buttonPosition: "right", //Position of button - 'right' is default - you can also choose 'left'
slideSpeed: "fast", //Speed of slide animation - "fast", "slow", or number in milliseconds such as 500
parentElement: "li", //Parent element type, class or ID - you don't need to change this if you're using a ul > li > ul pattern
childElement: "ul", //Child element type, class or ID - you don't need to change this if you're using a ul > li > ul pattern
headersOnly: false, //False is default - setting to true will make any link with sub-nav behave as if it were set to header only, making the link inaccessible - this option is useful if you are using the plugin for a non-navigation area
headersOnlyCheck: false, // False is default - set to true to apply the accordion only to links that are set as "header only" (have no href)
delayLink: false, //Delay following the href of links until after the accordion the has expanded
delayAmount: null //Time in milliseconds to delay before following href - will use "slideSpeed" by default if nothing else is set
}, options);
var container = this,
//Multiple levels variable
multi = settings.multipleLevels ? '': ' > ' + settings.childElement + ' > ';
//Add class to container
$(container)
.addClass('accordion-nav');
//Apply has-subnav class to lis with uls - also add accordion buttons with styles
$(multi + settings.parentElement, container).each(function(){
if ( ($(this).contents(settings.childElement).length > 0
&& settings.headersOnlyCheck == false) || (!($('> a', this).attr('href'))
&& settings.headersOnlyCheck == true) )
{
//Apply Class and styles to parent item
$(this).addClass('has-subnav')
.css('position', 'relative')
.find('>a')
.css('margin-' + settings.buttonPosition, settings.buttonWidth);
//Add expand button elements
$(' > ' + settings.childElement, this)
.before('<span class="accordion-btn-wrap"><a href="#"><span class="accordion-btn accordion-collapsed">'
+ settings.expandButtonText + '</span><a href="#"><span class="accordion-btn accordion-expanded">'
+ settings.collapseButtonText + '</span></a></span></a>');
//Apply Styles to expand button
$('.accordion-btn-wrap', this)
.css({
'width': settings.buttonWidth,
'position': 'absolute',
'top': 0,
'text-align': 'center',
'cursor': 'pointer',
'display': 'inline-block'
})
.css(settings.buttonPosition, 0);
$('.accordion-btn ', this)
.css({
'display': 'inline-block',
'width': '100%'
});
$('.accordion-expanded', this)
.css('display', 'none');
}
//Apply styles to <a> tags that are set to header only
if (!($('> a', this).attr('href')) || settings.headersOnly){
$(this)
.addClass('accordion-header-only')
.find('.accordion-btn-wrap')
.css({
'width': '100%',
'text-align': settings.buttonPosition
})
.find('.accordion-btn ')
.css({
'width': settings.buttonWidth,
'text-align': 'center'
});
}
//Delay Link Mode
if (settings.delayLink && !settings.headersOnly) {
var currentThis = this,
speed = settings.delayAmount != null ? settings.delayAmount : settings.slideSpeed;
if (speed == "fast") {
speed = 200;
} else if (speed == "slow") {
speed = 600;
}
$('> a', currentThis).on('click',function(e){
if (!$('> .accordion-btn-wrap', currentThis).hasClass("accordion-active")) {
e.preventDefault();
var href = $(this).attr('href');
clickToggle($('> .accordion-btn-wrap', currentThis));
//Go to link after delay
setTimeout(function(){
window.location = href;
}, speed)
}
})
}
});
var selectedNavAccordion = $(settings.parentElement + '.' + settings.selectedClass + ' > .accordion-btn-wrap', container);
//Debounced Button height event listener
var buttonheightResize = debounce(function(){
//Run button height
buttonheight();
//Expand Selected Channel
expandSelected();
}, 250);
$(window).on('resize', buttonheightResize);
//Set button heights
buttonheight();
//Expand Selected Channel
expandSelected();
//On click function
$(container).on('click', '.accordion-btn-wrap', function(e) {
e.preventDefault();
clickToggle(this);
});
//Callback
if (typeof callback == "function") {
callback();
}
/* Functions
*******************************/
//Click Toggle function
function clickToggle(element) {
var nextChild = $(element).next(settings.childElement),
currentExpandBtn = $('.accordion-expanded', element),
currentCollapseBtn = $('.accordion-collapsed', element),
parentObj = $(element).closest(settings.parentElement);
if (nextChild.is(':visible')) {
nextChild
.slideUp(settings.slideSpeed);
$(element)
.removeClass('accordion-active');
currentExpandBtn
.css('display', 'none');
currentCollapseBtn
.css('display', 'inline-block');
parentObj.add(parentObj.siblings('.active')).add(parentObj.find('.active')).removeClass('active');
} else {
$(element).closest(settings.childElement).find('.accordion-active')
.removeClass('accordion-active')
.next(settings.childElement)
.slideUp(settings.slideSpeed).prev()
.find('.accordion-expanded')
.css('display', 'none')
.parent().find('.accordion-collapsed')
.css('display', 'inline-block');
parentObj.add(parentObj.siblings('.active')).add(parentObj.find('.active')).removeClass('active');
$(element)
.addClass('accordion-active');
nextChild
.slideToggle(settings.slideSpeed);
currentExpandBtn
.css('display', 'inline-block');
currentCollapseBtn
.css('display', 'none');
parentObj.addClass('active');
}
}
//Expand Selected Channel Function
function expandSelected(){
if(settings.selectedExpand){
if(!settings.headersOnlyCheck){
selectedNavAccordion.find('.accordion-expanded')
.css('display', 'inline-block');
selectedNavAccordion.find('.accordion-collapsed')
.css('display', 'none');
selectedNavAccordion.addClass('accordion-active')
.next(settings.childElement)
.css('display', 'block');
selectedNavAccordion.closest(settings.parentElement)
.addClass('active');
} else {
$(settings.parentElement + '.' + settings.selectedClass + ' > ' + settings.childElement, container)
.css('display', 'block');
$(settings.parentElement + '.' + settings.selectedClass).addClass('active');
}
}
}
//Accordion Button Height Function
function buttonheight(){
$('.accordion-btn', container).each(function(){
//Show uls so heights are calculated correctly
$(settings.parentElement + '.has-subnav > ' + settings.childElement, container)
.css('display', 'block');
//Calculate and set heights
var parentItem = $(this).closest(settings.parentElement),
lineheight = $('> a', parentItem).innerHeight();
$(this)
.css({'line-height': lineheight + 'px', 'height': lineheight});
//Hide uls under lis and reset expand/collapse buttons
$(settings.parentElement + ((settings.headersOnlyCheck) ? ' ' : '.has-subnav > ') + settings.childElement, container)
.css('display', 'none');
$('.accordion-expanded')
.css('display', 'none');
$('.accordion-collapsed')
.css('display', 'inline-block');
})
}
//Debounce function
function debounce(func, wait, immediate) {
var timeout;
return function() {
var context = this, args = arguments;
var later = function() {
timeout = null;
if (!immediate) func.apply(context, args);
};
var callNow = immediate && !timeout;
clearTimeout(timeout);
timeout = setTimeout(later, wait);
if (callNow) func.apply(context, args);
};
};
});
}
})(jQuery);