自定义result返回值（转载）

 

Struts2 自定义Result

注意：我只要是解决自定义返回Json 和异常处理问题

新建一个类 AjaxResult   继承 StrutsResultSupport 看看代码吧

public class AjaxResult extends StrutsResultSupport {
    /**
     * serialVersionUID
     */
    private static final long serialVersionUID = 1L;
    private static final String AJAX_SUCCESS = "{\"success\":true}";
    private static final String SUCCESS_PERFIX = "{\"success\":true,result:[";
    private static final String FAILURE_PERFIX = "{\"success\":false,result:[],";
    private static final String SUFFIX = "]}";
    private Writer writer;
    private String defaultEncoding = "UTF-8";

    @Inject("struts.i18n.encoding")
    public void setDefaultEncoding(String encoding) {
        this.defaultEncoding = encoding;
    }

    protected void doExecute(String finalLocation, ActionInvocation invocation)
            throws Exception {
        Object action = invocation.getAction();
        String responseData = "";
        if ((action instanceof BaseAction)) {
            BaseAction ajaxAction = (BaseAction) action;
            HttpServletResponse response = ServletActionContext.getResponse();
            String encoding = getEncoding(finalLocation);
            String contentType = getContentType(finalLocation);
            if (encoding != null) {
                contentType = contentType + ";charset=" + encoding;
            }
            response.setContentType(contentType);
            String successData = ajaxAction.getResponseData();
            if (successData != null) {
                if ("success".equals(successData)) {
                    responseData = "{\"success\":true}";
                } else {
                    responseData = successData;
                }

            }
            // if(true){
            // String errorResultLocation = ajaxAction.getErrorResultLocation();
            // String exceptionMessage =
            // invocation.getStack().findString("exception.message");
            // exceptionMessage = exceptionMessage.replaceAll("\r", " ");
            // exceptionMessage = exceptionMessage.replaceAll("\n", " ");
            // exceptionMessage = exceptionMessage.replaceAll("\t", " ");
            // responseData = getFailureData(null, exceptionMessage);
            // }
            getWriter().write(responseData);
        }
    }

    private String getFailureData(String errorResultLocation,
            String exceptionMessage) {
        String errors = "errors:[{msg:\"" + exceptionMessage + "\"}]";
        // if (StringUtils.isNotBlank(errorResultLocation)) {
        // String target = ",\"target\":\"" + errorResultLocation;
        // return "{\"success\":false,result:[]," + errors + target + "\"}";
        // }

        return "{\"success\":false,result:[]," + errors + "}";
    }

    public void setWriter(Writer writer) {
        this.writer = writer;
    }

    protected Writer getWriter() throws IOException {
        if (this.writer != null) {
            return this.writer;
        }
        return ServletActionContext.getResponse().getWriter();
    }

    protected String getContentType(String templateLocation) {
        return "application/json";
    }

    protected String getEncoding(String templateLocation) {
        String encoding = this.defaultEncoding;
        if (encoding == null) {
            encoding = System.getProperty("file.encoding");
        }
        if (encoding == null) {
            encoding = "UTF-8";
        }
        return encoding;
    }
}

 

接下来，我们需要一个Struts 的配置文件

<package name="ajax-default" abstract="true" extends="struts-default">
        <result-types>
            <result-type name="ajax"
                class="com.guy.core.common.util.AjaxResult" />
        </result-types>
        <global-results>
            <result name="ajax" type="ajax" />
        </global-results>
        
    </package>

之后我们新建一个公用类  BaseAction

public class BaseAction extends ActionSupport implements ModelDriven,SessionAware, ParameterAware, ServletRequestAware, ServletResponseAware{
        /**
     * serialVersionUID
     */
    protected final Log logger = LogFactory.getLog(getClass());
    private static final long serialVersionUID = 1L;
    public String SUCCESS="SUCCESS";
    public static final String AJAX = "ajax";
    protected Map session;
    protected Map parameters;
    protected HttpServletRequest servletRequest;
    protected HttpServletResponse servletResponse;
    private String responseData;
    protected void createJSonData(String jsonData) {
        setResponseData(jsonData);
    }
    public String getResponseData() {
        return responseData;
    }
    public void setResponseData(String responseData) {
        this.responseData = responseData;
    }
    public Map getSession() {
        return session;
    }
    public void setSession(Map session) {
        this.session = session;
    }
    public Map getParameters() {
        return parameters;
    }
    public void setParameters(Map parameters) {
        this.parameters = parameters;
    }
    public HttpServletRequest getServletRequest() {
        return servletRequest;
    }
    public void setServletRequest(HttpServletRequest servletRequest) {
        this.servletRequest = servletRequest;
    }
    public HttpServletResponse getServletResponse() {
        return servletResponse;
    }
    public void setServletResponse(HttpServletResponse servletResponse) {
        this.servletResponse = servletResponse;
    }
    @Override
    public Object getModel() {
        return null;
    }
      
    
}

所有的action 都继承BaseAction   ModelDriven 我就不在解释了百度去

例如 

public class LoginAction extends BaseAction{

createJSonData("{\"success\":false,\"msg\":\"密码错误。\"}");

return AJAX;

 

 

这样我们的  BaseAction  就完事了，

对象ToString 转成 json 格式了，方便查看

 

 

@Override
     public String toString() {
          return ToStringBuilder.reflectionToString(this);
     }

 1  <interceptor-ref name="landingIct">  
 2                     <!-- 包括的方法，也就是拦截器拦截的方法<param name="includeMethods">方法1，方法2</param>      
 3                       
 4                     excludeMethods表示排除指定的方法，即不对标记为excludeMethods的方法进行拦截          
 5                     -->  
 6                     <param name="excludeMethods">landing</param>                  
 7                 </interceptor-ref>                  
 8                 <!-- 默认拦截器栈，如果不写则通过默认拦截器完成的功能将失效。如：国际化等等详细查看struts-default -->  
 9                 <!--  
10                     如果action中没有自定义的拦截器，struts2会为该action添加默认的拦截器，即defaultStack；如果action中用户自己添加了自定义拦截器，将覆盖掉系统的defaultStack，这时候需要我们显式调用该拦截器栈。 
11                  -->  

 

抛出异常  处理，在beasAction设置 IsAjaxError  AjaxErrorMessage

给get set 方法，  

新建 AjaxExceptionInterceptor

 public String intercept(ActionInvocation invocation)
    throws Exception
  {
    String result;
    try
    {
      result = invocation.invoke();
    }
    catch (Exception e) {
      if (this.logEnabled) {
        handleLogging(e);
      }

      List exceptionMappings = invocation.getProxy().getConfig().getExceptionMappings();
      String mappedResult = findResultFromExceptions(exceptionMappings, e);
      if (mappedResult != null) {
        result = mappedResult;
        Object action = invocation.getAction();
        if (action instanceof AjaxProvider) {
          AjaxProvider ajaxAction = (AjaxProvider)action;
          Map results = invocation.getProxy().getConfig().getResults();
          ResultConfig resultConfig = (ResultConfig)results.get(result);
          String location = (String)resultConfig.getParams().get("location");

          ajaxAtion.setIsAjaxError ("true");
          ajaxAction.setAjaxErrorMessage(location);
          result = "ajaxError";
        }
        super.publishException(invocation, new ExceptionHolder(e));
      }
      else {
        throw e;
      }
    }

    return result;
  }

 

 

baseAction  这里判断下是否有异常，有的花转成json输出到页面

 // if(true){
            // String errorResultLocation = ajaxAction.getErrorResultLocation();
            // String exceptionMessage =
            // invocation.getStack().findString("exception.message");
            // exceptionMessage = exceptionMessage.replaceAll("\r", " ");
            // exceptionMessage = exceptionMessage.replaceAll("\n", " ");
            // exceptionMessage = exceptionMessage.replaceAll("\t", " ");
            // responseData = getFailureData(null, exceptionMessage);
            // }