jsp自定义select选择标签和数据字典
jsp自定义标签，用于项目便捷开发。在实际项目开发中，我们大多数时候会采用数据字典来储存项目中一些数据，比如性别、国际、类型等，用数据字典存储很方便，因此在数据库中添加一张数据字典表t_dict_value，有做过的项目中采用两张表进行数据字典的管理，个人在设计数据字典的时候感觉一张表也够用了，不多说看建表语句：
CREATE TABLE `t_dict_value` ( `id` varchar(36) NOT NULL, `dict_name` varchar(36) default NULL, `item_code` varchar(36) default NULL, `item_desc` varchar(36) default NULL, PRIMARY KEY (`id`), UNIQUE KEY `item_code` (`item_code`) ) ENGINE=MyISAM DEFAULT CHARSET=gbk;
我的自定义标签是基于数据字典表使用的，当然后续业务中有需要也可以制作特定的自定义标签，接下来开始自定义标签，首先写一个DictSelectTag类，代码如下：
package com.infopatent.juangetljc.web.controller.core;
import java.io.IOException;
import java.util.List;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.TagSupport;
import org.apache.commons.lang3.StringUtils;
import com.infopatent.juangetljc.core.DictValue;
public class DictSelectTag extends TagSupport {
private String dictName;
private boolean defaultValue;
private String value;
private String name;
private String id;
private String cssClass;
private String styleClass;
private String multiple;
private String onChange;
public String getCssClass() {
return cssClass;
}
public void setCssClass(String cssClass) {
this.cssClass = cssClass;
}
public String getStyleClass() {
return styleClass;
}
public void setStyleClass(String styleClass) {
this.styleClass = styleClass;
}
public String getMultiple() {
return multiple;
}
public void setMultiple(String multiple) {
this.multiple = multiple;
}
public String getOnChange() {
return onChange;
}
public void setOnChange(String onChange) {
this.onChange = onChange;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
public String getDictName() {
return dictName;
}
public void setDictName(String dictName) {
this.dictName = dictName;
}
public boolean isDefaultValue() {
return defaultValue;
}
public void setDefaultValue(boolean defaultValue) {
this.defaultValue = defaultValue;
}
@Override
public int doEndTag() throws JspException{
DictValue dict = new DictValue();
List<DictValue> dict_list = dict.getRepository().findByProperty(DictValue.class,"dictName",dictName);
JspWriter out = pageContext.getOut();
StringBuffer sb = new StringBuffer();
sb.append("<select name='"+this.getName()+"' id='"+this.getId()+"'");
if(!StringUtils.isEmpty(this.getCssClass())){
sb.append("class=\"" + this.getCssClass() + "\" ");
}
if(!StringUtils.isEmpty(this.getStyleClass())){
sb.append("style=\"" + this.getStyleClass() + "\" ");
}
if(!StringUtils.isEmpty(this.getMultiple())){
sb.append("multiple=\"" + this.getMultiple() + "\" ");
}
if(!StringUtils.isEmpty(this.getOnChange())){
sb.append("onchange=\"" + this.getOnChange() + "\" ");
}
sb.append(">");
if(this.isDefaultValue()){
sb.append("<option value=''>--请选择--</option>");
}
for(DictValue dc:dict_list){
if(dc.getItemCode().equals(this.getValue())){
sb.append("<option value='"+dc.getItemCode()+"' selected='selected'>");
}else{
sb.append("<option value='"+dc.getItemCode()+"'>");
}
sb.append(dc.getItemDesc()+"</option>");
}
sb.append("</select>");
try {
out.write(sb.toString());
} catch (IOException e) {
// TODO Auto-generated catch block
throw new JspException(e);
}
return TagSupport.EVAL_PAGE;
}
}
再写一个DictLabelTag类用于显示字典中的值，代码如下：
package com.infopatent.juangetljc.web.controller.core;
import java.io.IOException;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.TagSupport;
import org.springframework.web.servlet.tags.form.OptionsTag;
import com.infopatent.juangetljc.core.DictValue;
public class DictLabelTag extends TagSupport {
private String dictName = "";
private String itemCode;
public String getDictName() {
return dictName;
}
public void setDictName(String dictName) {
this.dictName = dictName;
}
public String getItemCode() {
return itemCode;
}
public void setItemCode(String itemCode) {
this.itemCode = itemCode;
}
@Override
public int doEndTag() throws JspException {
DictValue dict = new DictValue();
JspWriter out = pageContext.getOut();
try {
out.write(dict.codeToName(getDictName(),getItemCode()));
} catch (IOException e) {
throw new JspException(e);
}
return TagSupport.EVAL_PAGE;
}
}
接下来配置tld文件，代码如下：
dict.tld: <?xml version="1.0" encoding="UTF-8"?> <taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd" version="2.0"> <description>SPay JSP Form Tag Library</description> <tlib-version>1.0</tlib-version> <short-name>dict</short-name> <uri>http://www.tljc.com/dict_tag</uri> <tag> <description>Renders an HTML 'select' element. Supports databinding to the selected option.</description> <name>select</name> <tag-class>com.infopatent.juangetljc.web.controller.core.DictSelectTag</tag-class> <body-content>JSP</body-content> <attribute> <name>defaultValue</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>value</name> <required>false</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>dictName</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>name</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>id</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>cssClass</name> <required>false</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>styleClass</name> <required>false</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>multiple</name> <required>false</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>onChange</name> <required>false</required> <rtexprvalue>true</rtexprvalue> </attribute> </tag> <tag> <name>itemdesc</name> <tag-class>com.infopatent.juangetljc.web.controller.core.DictLabelTag</tag-class> <body-content>JSP</body-content> <attribute> <description>The Dict Name config in dict_value</description> <name>dictName</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <description>The Dict Code config in dict_value</description> <name>itemCode</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> </tag> </taglib>
接下来在jsp页面里引入标签：
<%@taglib prefix="dict" uri="http://www.tljc.com/dict_tag" %>
这样便可以在jsp页面里使用定义的标签了：
<dict:select defaultValue="true" name="GJ" id="GJ" dictName="GJ" cssClass="form-control"/>
前提是要在字典表里加上“GJ”这条数据。
OK了!