将JSP值获取到HashMap页面

Question

我正在使用Google translator API来翻译客户端上传的文本。我有一个选择语言的下拉列表。但我需要它的代码把它发送给API。因此，我在一个具体的java类中使用了HashMap，如下所示

countryCode.java

public class CountryCode {

    public Map getCountryList()
    {
        String fileName = "countryCode.txt";
        Map<String, String> code = new HashMap<String, String>();
        String line;
        BufferedReader fileReader = null;
        try {
            fileReader = new BufferedReader(new FileReader(fileName));
            try {
                while((line = fileReader.readLine())!= null)
                {
                    String[] mapPart = line.split(":", 2);
                    if(mapPart.length >= 2)
                    {
                        String key = mapPart[0];
                        String val = mapPart[1];
                        code.put(key, val);
                    }
                }
                fileReader.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

         for (String key : code.keySet())
            {
                System.out.println(key + ":" + code.get(key));
            }
        return code;
    }
}

这是我的JSP页面，其中包含使用Bootstrap的下拉列表

translation.jsp

<section class="bg-light-gray">
<div class="container">
    <form action="TextTranslation" method="post" class="form" role="form" enctype="multipart/form-data">
        <div class="row">
            <div  id = "imageView" class="col-lg-8 center-block ">
            <div class="btn-group"> 
                <a class="btn btn-default dropdown-toggle btn-select2" data-toggle="dropdown" href="#">Select a Region <span class="caret"></span></a>
            <ul class="dropdown-menu">
        <% 
        %>
    </ul>
</div>

我不能理解如何访问这个dropdown.Do中的hashmap值你有什么想法吗？

Answer 1

如果您计划使用脚本，则可以在使用jsp标记之后使用纯Java

<jsp:useBean id="myId" class="package.name.CountryCode"/>

<% 
    Map<String, String> myCode = myId.getCountryList();
    // do something with myCode
%>

如果通过servlet将地图传递给Jsp，则可以简单地将地图存储为属性，然后通过表达式语言访问它

// within the Servlet you could set the attribute this way

Map<String, String> myCode = myId.getCountryList();
request.setAttribute("code", myCode);

// then within the Jsp you would access the map this way

${code.nameofyourfield}

// or

${code['nameofyourfield']}