最近要实现一个功能，就是checkbox跨页多选，在网上看了一下，资料很少，而且大多是不完全的。不过经过我的努力，终于做出来了。
JSP页面:
1,定义三个Hidden变量:
<INPUT type="hidden" name="all_selected">
<INPUT type="hidden" name="now_selected">
<INPUT type="hidden" name="no_selected"> 2,javascript
// 获取checkbox信息,选中,未选中,当前选中
function getCheckBoxInformation() {
var checkboxes = document.getElementsByName("checkbox");
var checkedStr = "";
var uncheckedStr = "";
var url = "";
for(var i = 0; i < checkboxes.length; i++) {
var checkbox = checkboxes[i];
if(checkbox.checked) {
checkedStr = checkedStr + "," + checkbox.value;
}else {
uncheckedStr = uncheckedStr + "," + checkbox.value;
}
}
document.form1.now_selected.value = checkedStr;
document.form1.no_selected.value = uncheckedStr;
}
// 页面onload的时候计算当前页被选中项,并在页面表示
function initPage() {
var all_selected = document.form1.all_selected.value;
if(all_selected != "" && all_selected!= null) {
var arrall_select = all_selected.split(",");
if(arrall_select.length > 0) {
for(var k = 0; k < arrall_select.length; k++) {
for(var i = 0; i < document.form1.checkbox.length; i++) {
if(document.form1.checkbox[i].value == arrall_select[k]) {
document.form1.checkbox[i].checked = true;
}
}
}
}
}
} 每次翻页的时候调用getCheckBoxInformation()方法,页面加载的时候调用initPage()方法.
在后台，每次翻页时调用方法
public String doubleSpread(String all_select, String now_selected,
String no_selected) {
// 获取当前选中的项目
if (now_selected != "" && now_selected != null) {
String[] all_now_select = now_selected.split(",");
// 将当前选中项目加入列表
for (int i = 1; i < all_now_select.length; i++) {
String strBoxSelected = all_now_select[i];
String strSearchWith = strBoxSelected + ",";
if (all_select.indexOf(strSearchWith) == -1) {
all_select = all_select + strSearchWith;
}
}
}
String[] all_select_str = all_select.split(",");
int[] all_select_int = new int[all_select_str.length];
for (int i = 0; i < all_select_str.length; i++) {
if (all_select_str[i] != "") {
int j = Integer.parseInt(all_select_str[i]);
all_select_int[i] = j;
}
}
// 获取当前未选中项目
if (no_selected != "" && no_selected != null) {
String[] all_now_no_select = no_selected.split(",");
// 将当前未选中项目从列表中删除
for (int i = 1; i < all_now_no_select.length; i++) {
int all_now_no_select_value = Integer
.parseInt(all_now_no_select[i]);
for (int k = 0; k < all_select_int.length; k++) {
if (all_select_int[k] == all_now_no_select_value) {
all_select = all_select.replaceAll(String
.valueOf(all_now_no_select_value)
+ ",", "");
}
}
}
}
return all_select;
}
}
将此方法返回的all_select再传到JSP页面上并赋值给那个隐藏域,到此，功能就实现了。
注：
1、文中把String转化int实在没有必要，可以直接使用String数组。优化后的代码：
public String doubleSpread(String all_select, String now_selected,
String no_selected) {
// 获取当前选中的项目
if (now_selected != "" && now_selected != null) {
String[] all_now_select = now_selected.split(",");
// 将当前选中项目加入列表
for (int i = 1; i < all_now_select.length; i++) {
String strBoxSelected = all_now_select[i];
String strSearchWith = strBoxSelected + ",";
if (all_select.indexOf(strSearchWith) == -1) {
all_select = all_select + strSearchWith;
}
}
}
if (all_select != "" && all_select != null) {
String[] all_select_str = all_select.split(",");
// 获取当前未选中项目
if (no_selected != "" && no_selected != null) {
String[] all_now_no_select = no_selected.split(",");
// 将当前未选中项目从列表中删除
for (int i = 1; i < all_now_no_select.length; i++) {
for (int k = 0; k < all_select_str.length-1; k++) {
if (all_select_str[k].equals(all_now_no_select[i])) {
all_select = all_select.replaceFirst(all_now_no_select[i]
+ ",", "");
}
}
}
}
}
return all_select;
}2、最后使用replaceAll和indexOf可能出些一些小BUG，例如只想替换9，但是19的9也会被替换；想添加5，由于存在15就不能添加了。可以考虑使用replaceFirst，但是最好是使用List实现，下面贴出代码。
public String doubleSpread(String all_select, String now_selected, String no_selected) {
//获取当前选中的项目加入al
List al = new ArrayList();
if(all_select != "" && all_select != null)
{
String[] all_select_str = all_select.split(",");
for(int a=0;a<all_select_str.length;a++)
{
al.add(all_select_str[a]);
}
}
//将当前选中项目加入列表
if (now_selected != "" && now_selected != null) {
String[] all_now_select = now_selected.split(",");
for (int i = 1; i < all_now_select.length; i++) {
if (!al.contains(all_now_select[i])) {
al.add(all_now_select[i]);
}
}
}
//将当前未选中项目从列表中删除
if (no_selected != "" && no_selected != null) {
String[] all_now_no_select = no_selected.split(",");
for (int i = 1; i < all_now_no_select.length; i++) {
if (al.contains(all_now_no_select[i])) {
al.remove(all_now_no_select[i]);
}
}
}
all_select=al.toString().replaceAll(" +","");;
all_select=all_select.substring(1,all_select.length()-1)+",";
return all_select;
}