兩級聯動Select的TAG實現

[b]JSP實現太複雜而且不方便,那來個幽雅點的Tag包裝![/b]
[code]package com.jamesby.cm.common.utils;

import java.util.List;

import javax.servlet.jsp.tagext.Tag;
import javax.servlet.jsp.tagext.TagSupport;

public class TwoLevelDropdownTag extends TagSupport {
public final String _PAGE_SCOPE = "page";
public final String _REQUERT_SCOPE = "request";
public final String _SESSION_SCOPE = "session";
public final String _APPLICATION_SCOPE = "application";

public final String _JS_GET_METHOD_NAME = "_do_get_second";

public final String _JS_ONE_ARRAY_NAME = "_js_one_array_name";

public final String _JS_TWO_ARRAY_NAME = "_js_two_array_name";

public final String _STYLE_WIDTH = "100";

public final String _PARAM_FORM_NAME = "cmForm";

public final String _TWO_DEFAULT_TEXT = "";

private String paramFormName = _PARAM_FORM_NAME;

private String paramOneIdField;

private String paramOneNameField;

private String paramLinkField;

private String paramTwoIdField;

private String paramTwoNameField;

private java.util.List paramTwoArrayList;

private String paramTwoDefaultText = _TWO_DEFAULT_TEXT;

private String paramStyleWidth = _STYLE_WIDTH;

private String paramJsOneArrayName = _JS_ONE_ARRAY_NAME;

private String paramJsTwoArrayName = _JS_TWO_ARRAY_NAME;

private String paramJsGetMethodName = _JS_GET_METHOD_NAME;


private String paramPreJavascript = "";

private String paramPostJavascript = "";

private String scope = _REQUERT_SCOPE;

private String itemsName="items";

public String getItemsName() {
return itemsName;
}

public void setItemsName(String itemsName) {
this.itemsName = itemsName;
}
public TwoLevelDropdownTag() {
}

public int doEndTag() {
try{
if (!_PAGE_SCOPE.equals(scope)&&!_REQUERT_SCOPE.equals(scope)&&!_SESSION_SCOPE.equals(scope)&&!_APPLICATION_SCOPE.equals(scope))
{
throw new RuntimeException("scope is invalid.....................");
}

if (_PAGE_SCOPE.equals(scope))
{
paramTwoArrayList = (List)this.pageContext.getAttribute(itemsName);
}
if (_REQUERT_SCOPE.equals(scope))
{
paramTwoArrayList = (List)this.pageContext.getRequest().getAttribute(itemsName);
}
if (_SESSION_SCOPE.equals(scope))
{
paramTwoArrayList = (List)this.pageContext.getSession().getAttribute(itemsName);
}
if (_APPLICATION_SCOPE.equals(scope))
{
paramTwoArrayList = (List)this.pageContext.getServletContext().getAttribute("itemsName");
}

if (null==paramTwoArrayList) throw new RuntimeException("items not exists............");

java.io.Writer out = this.pageContext.getOut();
out.write("<script language=\"javascript\">\n");
out.write("<!--\n");
out.write(getParamPreJavascript());
out.write("var "+getParamJsTwoArrayName()+" = new Array("+getParamTwoArrayList().size()+");\n");
java.util.HashMap _local = null;
for (int i=0;i<getParamTwoArrayList().size();i++)
{
_local = (java.util.HashMap)getParamTwoArrayList().get(i);
out.write(getParamJsTwoArrayName()+"["+i+"] = new Array(3);\n");
out.write(getParamJsTwoArrayName()+"["+i+"][0] = '"+_local.get(getParamTwoIdField())+"';\n");
out.write(getParamJsTwoArrayName()+"["+i+"][1] = '"+_local.get(getParamTwoNameField())+"';\n");
out.write(getParamJsTwoArrayName()+"["+i+"][2] = '"+_local.get(getParamLinkField())+"';\n");
}
out.write("function "+getParamJsGetMethodName()+"(){\n");
out.write("firstid = "+getParamFormName()+"."+getParamOneIdField()+".options["+getParamFormName()+"."+getParamOneIdField()+".selectedIndex].value;\n");
out.write("a = "+getParamFormName()+"."+getParamTwoIdField()+".length;\n");
out.write("for (i=0;i<a;i++){\n");
out.write(getParamFormName()+"."+getParamTwoIdField()+".remove(0);\n");
out.write("}\n");
out.write("op = new Option();\n");
out.write("op.text=\""+getParamTwoDefaultText()+"\";\n");
out.write("op.value=\"\";\n");
out.write(getParamFormName()+"."+getParamTwoIdField()+".add(op);\n");
out.write("if (firstid==0){\n");
out.write("return;\n");
out.write("}\n");
out.write("for (i=0;i<"+getParamJsTwoArrayName()+".length;i++){\n");
out.write("if ("+getParamJsTwoArrayName()+"[i][2]==firstid)\n");
out.write("{\n");
out.write("op1 = new Option();\n");
out.write("op1.value = "+getParamJsTwoArrayName()+"[i][0];\n");
out.write("op1.text = "+getParamJsTwoArrayName()+"[i][1];\n");
out.write(getParamFormName()+"."+getParamTwoIdField()+".options.add(op1);\n");
out.write("}\n");
out.write("}\n");
out.write(getParamFormName()+"."+getParamTwoIdField()+".style.width="+getParamStyleWidth()+";\n");
out.write("}\n");
out.write(getParamPostJavascript());
out.write("//-->\n");
out.write("</script>\n");
out.flush();
}catch(java.io.IOException ex)
{
ex.printStackTrace();
}
return Tag.EVAL_PAGE;
}

public String get_JS_GET_METHOD_NAME() {
return _JS_GET_METHOD_NAME;
}
public String get_JS_ONE_ARRAY_NAME() {
return _JS_ONE_ARRAY_NAME;
}
public String get_JS_TWO_ARRAY_NAME() {
return _JS_TWO_ARRAY_NAME;
}


public String get_PARAM_FORM_NAME() {
return _PARAM_FORM_NAME;
}

public String get_STYLE_WIDTH() {
return _STYLE_WIDTH;
}

public String get_TWO_DEFAULT_TEXT() {
return _TWO_DEFAULT_TEXT;
}

public String getParamFormName() {
return paramFormName;
}

public void setParamFormName(String paraFormName) {
this.paramFormName = paraFormName;
}

public String getParamJsGetMethodName() {
return paramJsGetMethodName;
}

public void setParamJsGetMethodName(String paramJsGetMethodName) {
this.paramJsGetMethodName = paramJsGetMethodName;
}

public String getParamJsOneArrayName() {
return paramJsOneArrayName;
}

public void setParamJsOneArrayName(String paramJsOneArrayName) {
this.paramJsOneArrayName = paramJsOneArrayName;
}

public String getParamJsTwoArrayName() {
return paramJsTwoArrayName;
}

public void setParamJsTwoArrayName(String paramJsTwoArrayName) {
this.paramJsTwoArrayName = paramJsTwoArrayName;
}

public String getParamLinkField() {
return paramLinkField;
}

public void setParamLinkField(String paramLinkField) {
this.paramLinkField = paramLinkField;
}

public String getParamOneIdField() {
return paramOneIdField;
}

public void setParamOneIdField(String paramOneIdField) {
this.paramOneIdField = paramOneIdField;
}

public String getParamOneNameField() {
return paramOneNameField;
}

public void setParamOneNameField(String paramOneNameField) {
this.paramOneNameField = paramOneNameField;
}

public String getParamPostJavascript() {
return paramPostJavascript;
}

public void setParamPostJavascript(String paramPostJavascript) {
this.paramPostJavascript = paramPostJavascript;
}

public String getParamPreJavascript() {
return paramPreJavascript;
}

public void setParamPreJavascript(String paramPreJavascript) {
this.paramPreJavascript = paramPreJavascript;
}

public String getParamStyleWidth() {
return paramStyleWidth;
}

public void setParamStyleWidth(String paramStyleWidth) {
this.paramStyleWidth = paramStyleWidth;
}


public String getParamTwoDefaultText() {
return paramTwoDefaultText;
}

public void setParamTwoDefaultText(String paramTwoDefaultText) {
this.paramTwoDefaultText = paramTwoDefaultText;
}

public String getParamTwoIdField() {
return paramTwoIdField;
}

public void setParamTwoIdField(String paramTwoIdField) {
this.paramTwoIdField = paramTwoIdField;
}

public String getParamTwoNameField() {
return paramTwoNameField;
}

public void setParamTwoNameField(String paramTwoNameField) {
this.paramTwoNameField = paramTwoNameField;
}

public String getScope() {
return scope;
}

public void setScope(String scope) {
this.scope = scope;
}

public java.util.List getParamTwoArrayList() {
return paramTwoArrayList;
}
}[/code]


[code]<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.1//EN" "http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd">
<taglib>
<tlibversion>1.0</tlibversion>
<jspversion>1.1</jspversion>
<shortname>display</shortname>
<uri>http://jakarta.apache.org/taglibs/display</uri>
<info>
A description of the display tag library goes here...
</info>
<tag>
<name>select2</name>
<tagclass>com.jamesby.cm.common.utils.TwoLevelDropdownTag</tagclass>
<bodycontent>EMPTY</bodycontent>
<attribute>
<name>paramOneIdField</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramOneNameField</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramLinkField</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramTwoIdField</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramTwoNameField</name>
<required>true</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramFormName</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>scope</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>itemsName</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramTwoDefaultText</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramStyleWidth</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramJsOneArrayName</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramJsTwoArrayName</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramJsGetMethodName</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramPreJavascript</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
<attribute>
<name>paramPostJavascript</name>
<required>false</required>
<rtexprvalue>true</rtexprvalue>
</attribute>
</tag>
</taglib>[/code]

[code]<%@ page contentType="text/html;charset=GBK" language="java"%>
<%@ taglib uri="/tags/taglib_xb" prefix="xb"%>
<%
java.util.List paramTwoArrayList = new java.util.ArrayList();
java.util.Map a1 = new java.util.HashMap();
a1.put("compid","1");
a1.put("deptid","10");
a1.put("deptname","行政部");

java.util.Map b1 = new java.util.HashMap();
b1.put("compid","1");
b1.put("deptid","20");
b1.put("deptname","財務部");

java.util.Map c1 = new java.util.HashMap();
c1.put("compid","2");
c1.put("deptid","30");
c1.put("deptname","市場部");

paramTwoArrayList.add(a1);
paramTwoArrayList.add(b1);
paramTwoArrayList.add(c1);
pageContext.setAttribute("items",paramTwoArrayList);
%>
<xb:select2 paramOneIdField="compid" paramOneNameField="compname" paramLinkField="compid" paramTwoIdField="deptid" paramTwoNameField="deptname" scope="page"/>
<form name="cmForm">
公司名稱<select name="compid" οnchange="_do_get_second();" style="width:100">
<option value=""></option>
<option value="1">公司一</option>
<option value="2">公司二</option>
<option value="3">公司三</option>
</select>
部門名稱
<select name="deptid" style="width:100">
</select>
</form>[/code]