在Struts2，可以使用<s:radio>標籤來創建一個HTML單選按鈕。有很多方法來填充數據到單選按鈕，可以通過List, OGNL 或 Object。請查看下面的例子就知道了。

Struts2 <s:radio> 示例

舉個例子來說明如何使用列表，OGNL和對象數據填充到Struts2中，使用<s:radio>標籤創建一個單選按鈕。

1. 動作 - Action

Action類來創建性別和語言值單選按鈕列表。

RadioButtonAction.java

package com.yiibai.common.action;

import java.util.ArrayList;
import java.util.List;

import com.yiibai.common.model.Language;
import com.opensymphony.xwork2.ActionSupport;

public class RadioButtonAction extends ActionSupport{

private List<String> genders;
private List<Language> languages ;

private String yourGender;
private String yourAnswer;
private String yourLanguage;

private static final String MALE = "male";
private static final String FEMALE = "female";
private static final String UNKNOWN = "unknown";

public RadioButtonAction(){

    genders = new ArrayList<String>();
    genders.add(MALE);
    genders.add(FEMALE);
    genders.add(UNKNOWN);

    languages = new ArrayList<Language>();
    languages.add( new Language("EN", "English") );
    languages.add( new Language("FR", "France") );
    languages.add( new Language("CN\_ZH", "Chinese") );
    languages.add( new Language("DE", "German") );

}

//return default gender value
public String getDefaultGenderValue(){
    return UNKNOWN;
}

//return default language value
public String getDefaultLanguageValue(){
    return "CN\_ZH";
}

public String execute() {
    return SUCCESS;
}
public String display() {
    return NONE;
}

//getter ad setter methods

}

Language.java

**package com.yiibai.common.model;

public class Language{

private String languageCode;
private String languageDisplay;

public String getLanguageCode() {
    return languageCode;
}
public void setLanguageCode(String languageCode) {
    this.languageCode = languageCode;
}
public String getLanguageDisplay() {
    return languageDisplay;
}
public void setLanguageDisplay(String languageDisplay) {
    this.languageDisplay = languageDisplay;
}

public Language(String languageCode, String languageDisplay) {
    this.languageCode = languageCode;
    this.languageDisplay = languageDisplay;
}

}**

2. 結果頁面

結果頁面是使用Struts2 「s:radio」 通過List, OGNL 和 object來創建的三個單選按鈕。

radiobutton.jsp

<%@ taglib prefix="s" uri="/struts-tags" %>

Struts 2 radio button example

<s:form action="resultAction" namespace="/">

<s:submit value="submit" name="submit" />

result.jsp

<%@ taglib prefix="s" uri="/struts-tags" %>

Struts 2 radio button example

Your Selected Gender :

Your Selected Language :

Your Selected Answer :

3. struts.xml

<action name="radioButtonAction" 
     class="com.yiibai.common.action.RadioButtonAction" method="display">
    <result name="none">/pages/radiobutton.jsp</result>
</action>

<action name="resultAction" class="com.yiibai.common.action.RadioButtonAction">
    <result name="success">/pages/result.jsp</result>
</action>

5. 示例

http://localhost:8080/struts2radio/radioButtonAction.action

http://localhost:8080/struts2radio/resultAction.action

要了解如何預選值，讀這篇文章 – 在Struts2的單選按鈕預選值

參數

1. http://struts.apache.org/2.0.11.2/docs/radio.html
2. http://struts.apache.org/2.1.8.1/docs/struts-2-form-tags.html