Servlet获取参数Map

Servlet获取请求参数的Map非常的方便，下面把几个情形给列举出来。

一、加入依赖：

<dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.4</version>
        </dependency>
        <dependency>
            <groupId>commons-fileupload</groupId>
            <artifactId>commons-fileupload</artifactId>
            <version>1.3.1</version>
</dependency>

二、Servlet获取参数Map,支持GET请求，支持POST表单提交

/**
     * Servlet获取参数Map,支持GET请求，支持POST表单提交
     * @param request
     * @return
     */
    private static Map getParameterFormUrlEncoded(HttpServletRequest request){
        Map properties = request.getParameterMap();
        Map returnMap = new HashMap();
        Iterator entries = properties.entrySet().iterator();
        Entry entry;
        String key = "";
        String value = "";
        
        while(entries.hasNext()){
            entry = (Entry)entries.next();
            key = (String)entry.getKey();
            Object valueObj = entry.getValue();
            
            if(null == valueObj){
                value = "";
            }else if(valueObj instanceof String[]){
                String[] values = (String[])valueObj;
                for(int i = 0;i < values.length;i++){
                    value = values[i]+",";
                }
                value = value.substring(0, value.length()-1); 
            }else{
                value = valueObj.toString();
            }
            returnMap.put(key, value);
        }
        return returnMap;
   }

三、form-data 支持POST，需要用到commons-fileupload来获取

/**
     * form-data 支持POST
     * @param request
     * @return
     * @throws UnsupportedEncodingException
     */
    private static Map getParamMapFormData(HttpServletRequest request) throws UnsupportedEncodingException{
        DiskFileItemFactory factory = new DiskFileItemFactory(); 
        ServletFileUpload upload = new ServletFileUpload(factory); 
        upload.setHeaderEncoding("UTF-8");
        List items = null;
        try {
            items = upload.parseRequest(request);
        } catch (FileUploadException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Map returnMap = new HashMap(); 
        for(Object object:items){
            FileItem fileItem = (FileItem) object; 
            if (fileItem.isFormField()) { 
                returnMap.put(fileItem.getFieldName(), fileItem.getString("utf-8"));//如果你页面编码是utf-8的 
            }
        }
        return returnMap;
    }