How to auto select drop down box value in Struts 2

In Struts 2, the HTML drop down box can be rendered via <s:select> tag. To auto select a default value for a drop down box, just declared a “value” attribute in the <s:select> tag, and set the default value accordingly.

1. Java List example

A Java list to generate the select options for the drop down box.

//...
public class SelectAction extends ActionSupport{
 
	private List<String> searchEngine;
	private String yourSearchEngine;
 
	//set default value
	public String getDefaultSearchEngine() {
		return "yahoo.com";
	}
	public SelectAction(){	
		searchEngine = new ArrayList<String>();
		searchEngine.add("google.com");
		searchEngine.add("bing.com");
		searchEngine.add("yahoo.com");
		searchEngine.add("baidu.com");
	}
	//...
}

<s:select> tag to render the HTML drop down box. The value=”defaultSearchEngine” will calle the corresponds Action class getDefaultSearchEngine() method to return a default search engine value.

	<s:select label="What's your favor search engine" 
		headerKey="-1" headerValue="Select Search Engines"
		list="searchEngine" 
		name="yourSearchEngine" 
		value="defaultSearchEngine" />

In this example, the drop down box will auto select the “yahoo.com” as the default option.

2. OGNL List example

Create a drop down box via OGNL expression, and set the default value in the “value” attribute directly.

	<s:select label="Select a month" 
		headerKey="-1" headerValue="Select Month"
		list="#{'1':'Jan', '2':'Feb', '3':'Mar', '4':'Apr'}" 
		name="yourMonth" 
		value="2" />

In this example, the drop down box will auto select the “2″ (Feb) as the default option.

Note : You can find more similar articles at - Struts 2.x Tutorials

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