Struts2中使用AJAX

1、使用HttpServletResponse用流的形式輸出

在Action中直接使用HttpServletResponse的getWriter()方法使用PrintWriter輸出；

public class AjaxPrizeKindsAction extends ActionSupport {
	private Logger logger = Logger.getLogger(AjaxPrizeKindsAction.class);
	private IPrizeKindInfoService prizeKindInfoService;

	@Override
	public String execute() throws Exception {
		logger.debug("enter into AjaxPrizeKindsAction");
		List<PrizeKindInfoVO> list = prizeKindInfoService.findAllByCondition();
		
		if(list != null && list.size() > 0 ){
			Object[] temp = list.toArray();
			JSONArray jsonArray = JSONArray.fromObject(temp);
			
			String json = jsonArray.toString();
			WebUtil.printOut(json, "text/html", "UTF-8");
		}else{
			String json = null;
			WebUtil.printOut(json, "text/html", "UTF-8");
		}
		return null;
	}
	public void setPrizeKindInfoService(IPrizeKindInfoService prizeKindInfoService) {
		this.prizeKindInfoService = prizeKindInfoService;
	}
}

WebUtil工具類：

public class WebUtil {
   /**
	 * 頁面輸出
	 * @param res         輸入內容
	 * @param contentType 內容格式，可空
	 * @param encoding    編碼格式，可空
	 * @throws Exception 
	 */
	public static void printOut(String res, String contentType, String encoding) throws IOException{ 
		PrintWriter out = null;
		if(contentType == null || contentType.trim().equals("")){
			contentType = "text/html";
		}
		if(encoding == null || encoding.trim().equals("")) {
			encoding = "UTF-8";
		}
		logger.debug("contentType: " +contentType + " | encoding: " + encoding);
		try{
			HttpServletResponse response = ServletActionContext.getResponse();
			response.setContentType(contentType);
			response.setCharacterEncoding(encoding);
			response.getWriter();
			out = response.getWriter();
			out.println(res);
		}catch (IOException e) {
			logger.error("IOException in printOut of BaseAction：", e);
			throw e;
		}
		finally {
			if(out != null) {
				out.flush();
				out.close();
			}
		}
	}
}

在JSP中的AJAX請求：

$.post(url, params, function (result,textStatus){
			if(textStatus == 'success'){
				if(result != null){
				//處理result 
			}
}

struts.xml中的配置：

<!-- ajax -->
    <package name="ajax" extends="struts-default" namespace="/ajax">
	    <action name="" class="com.test.controller.AjaxPrizeKindsAction"></action>
    </package>

這樣的作法是藉助工具類自定義返回流的形式，比較複雜，而且跟struts2沒有多大關係，struts2支持一種

stream類型的Ruselt,這種類型能夠直接向客戶端瀏覽器生成二進制響應，文本響應。

2、使用stram類型的Result實現AJAX

public class AjaxPrizeKindsAction extends ActionSupport {
	private Logger logger = Logger.getLogger(AjaxPrizeKindsAction.class);
    private InputStream inputStream;    

	@Override
	public String execute() throws Exception {
		logger.debug("enter into AjaxPrizeKindsAction");
		    String a = "{\"a\":\"c\",\"sd\":\"ds\"}";
			inputStream = new ByteArrayInputStream(a.toString().getBytes());
		    return SUCCESS;
	}

    public InputStream getInputStream() {
		return inputStream;
	}

	public void setInputStream(InputStream inputStream) {
		this.inputStream = inputStream;
	}
   
}

xml中的配置

<action name="ajaxprizekinds" class="com.shcredit.controller.prize.prizeactivity.prizeactdet.AjaxPrizeKindsAction">
			<result name="success" type="stream">
				<!-- 指定下載文件的文件類型 -->
				<param name="contentType">text/html</param>
				<param name="inputName">inputStream</param>
			</result>
</action>