我需要帮助，使用struts2动作类将国家/地区名称从json文件获取到select2下拉列表。
我为前端编写了一个jsp文件，struts.xml，web.xml和struts操作类。通过select2调用动作类时出现错误。
当我单击select2下拉列表时，ajax调用了action方法以在列表中显示国家名称。但是什么都没显示
index.jsp
<%@ taglib prefix="s" uri="/struts-tags"%>
<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="x-ua-compatible" content="IE=edge" />
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<link href="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/css/select2.min.css" rel="stylesheet" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/select2/4.0.3/js/select2.min.js"></script>
<body>
<s:form action="fetchCountries">
<select class="myselect" name="countriesL.code" style="width: 500px;">
<option value="0">Select</option>
</select>
</s:form>
<script type="text/javascript">
$(document).ready(function () {
$('.myselect').select2({
placeholder: 'Select an item',ajax: {
url: 'fetchCountries',dataType: 'json',data: function (params)
{
var query = {
search: params.term,//this is Sending Input key by search
userInput: params.term //this is Sending Input key by userInput
}
return query;
},processResults: function (data)
{
//Return Response
console.log(data);
var results = $.map(data.countriesL,function (obj)
{
return {
id: obj.id,//text: obj.text
};
});
console.log(results); //Printing Response
return {
results: results,};
},"more": true,cache: true
}
});
});
</script type>
</body>
</html>
struts.xml
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.devMode" value="true" />
<package name="default" namespace="" extends="struts-default" >
<action name="Getountries"
class="com.getjsondata.Getountries" >
<result>/index.jsp</result>
</action>
<action name="fetchCountries" class="com.getjsondata.Getountries" method="findcountry">
<result name="success"></result>
</action>
</package>
</struts>
struts动作类
package com.getjsondata;
import com.opensymphony.xwork2.actionSupport;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Map;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.*;
public class Getountries extends actionSupport
{
String userInput;
ArrayList<String> countriesL;
public String getUserInput() {
return userInput;
}
public void setUserInput(String userInput) {
this.userInput = userInput;
}
public ArrayList<String> getcountriesL() {
return countriesL;
}
public void setCountriesL(ArrayList<String> countriesL) {
this.countriesL = countriesL;
}
public String findcountry() throws Exception {
countries cl = new countries();
//countriesL=cl.getIdList(userInput);
countriesL=cl.getcountries(userInput);
return "success";
}
}
countries.java
package com.getjsondata;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;
import org.json.simple.parser.ParseException;
public class countries
{
public String countryName;
ArrayList<String> idList = new ArrayList<String>();
public ArrayList<String> getIdList(String userInput) {
return idList;
}
public void setIdList(ArrayList<String> idList) {
this.idList = idList;
}
public String getcountryName() {
return countryName;
}
public void setCountryName(String countryName) {
this.countryName = countryName;
}
public ArrayList<String> getcountries(String userInput) throws Exception
{
try{
System.out.println("executing execut() method");
String path = "C:/Workspace2/Select2Json/resources/countries.json";
JSONParser parser = new JSONParser();
JSONArray a = (JSONArray) parser.parse(new FileReader(path));
for (Object o : a)
{
JSONObject person = (JSONObject) o;
String id = (String) person.get("text");
idList.add(id);
System.out.println(id);
}
}catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
}
return idList;
}
}
示例json文件
[
{
"id": "AX","text": "Ă…land Islands"
},{
"id": "PK","text": "Pakistan"
},{
"id": "SE","text": "Sweden"
},{
"id": "BV","text": "Bouvet Island"
}
]