如何在oracle maf中更新/刷新列表视图的列表项？

我有一份任务清单。当我删除其中一个任务时，我的列表仍会在列表中显示该任务，但在服务器端，我已更新了列表，因此无法刷新列表。我正在从服务器获取新任务阵列，但无法显示它。当我再次启动我的应用程序时，它会显示更新的列表。如何在不关闭应用程序的情况下获取更新列表？这两次我都更新了阵列，但无法在视图上显示它

    public class ModelClass {
private String message;

private String statusCode;

private Response[] res = null;

protected transient PropertyChangeSupport _propertyChangeSupport = new PropertyChangeSupport(this);

public ModelClass() {
    super();

    clickEvent(new ActionEvent());

}

public static String taskId;

public void setTaskId(String taskId) {
    System.out.print(taskId);
    this.taskId = taskId;
}

public String getTaskId() {
    return taskId;
}


public PropertyChangeSupport getPropertyChangeSupport() {
    return _propertyChangeSupport;
}

public void setMessage(String message) {
    String oldMessage = this.message;
    this.message = message;
    _propertyChangeSupport.firePropertyChange("message", oldMessage, message);
}

public String getMessage() {
    return message;
}

public void setStatusCode(String statusCode) {
    String oldStatusCode = this.statusCode;
    this.statusCode = statusCode;
    _propertyChangeSupport.firePropertyChange("statusCode", oldStatusCode, statusCode);
}

public String getStatusCode() {
    return statusCode;
}


public void setRes(Response[] res) {
    Response[] oldRes = this.res;
    this.res = res;
    System.out.println(res);
    _propertyChangeSupport.firePropertyChange("res", oldRes, res);
    System.out.println("refreshing here ");

}

public Response[] getRes() {

    return res;
}


@Override
public String toString() {
    return "ClassPojo [response = " + res + ", message = " + message + ", statusCode = " + statusCode + "]";
}


public void addPropertyChangeListener(PropertyChangeListener l) {
    _propertyChangeSupport.addPropertyChangeListener(l);
}

public void removePropertyChangeListener(PropertyChangeListener l) {
    _propertyChangeSupport.removePropertyChangeListener(l);
}


public class Response {
    private String taskId;

    private String taskType;

    private Integer taskTime;

    private String taskName;

    private PropertyChangeSupport _propertyChangeSupport = new PropertyChangeSupport(this);

    Response(String taskId, String taskType, String taskName) {
        super();
        this.taskId = taskId;
        this.taskType = taskType;
        this.taskName = taskName;

    }

    public void setTaskId(String taskId) {
        String oldTaskId = this.taskId;
        this.taskId = taskId;
        _propertyChangeSupport.firePropertyChange("taskId", oldTaskId, taskId);
    }

    public String getTaskId() {
        return taskId;
    }

    public void setTaskType(String taskType) {
        String oldTaskType = this.taskType;
        this.taskType = taskType;
        _propertyChangeSupport.firePropertyChange("taskType", oldTaskType, taskType);
    }

    public String getTaskType() {
        return taskType;
    }

    public void setTaskTime(Integer taskTime) {
        Integer oldTaskTime = this.taskTime;
        this.taskTime = taskTime;
        _propertyChangeSupport.firePropertyChange("taskTime", oldTaskTime, taskTime);
    }

    public Integer getTaskTime() {
        return taskTime;
    }

    public void setTaskName(String taskName) {
        String oldTaskName = this.taskName;
        this.taskName = taskName;
        _propertyChangeSupport.firePropertyChange("taskName", oldTaskName, taskName);
    }

    public String getTaskName() {
        return taskName;
    }


    @Override
    public String toString() {
        return "ClassPojo [taskId = " + taskId + ", taskType = " + taskType + ", taskTime = " + taskTime +
               ", taskName = " + taskName + "]";
    }

    public void addPropertyChangeListener(PropertyChangeListener l) {
        _propertyChangeSupport.addPropertyChangeListener(l);
    }

    public void removePropertyChangeListener(PropertyChangeListener l) {
        _propertyChangeSupport.removePropertyChangeListener(l);
    }
}

protected transient ProviderChangeSupport providerChangeSupport = new ProviderChangeSupport(this);

public void addProviderChangeListener(ProviderChangeListener l) {

    providerChangeSupport.addProviderChangeListener(l);

}

public void removeProviderChangeListener(ProviderChangeListener l) {

    providerChangeSupport.removeProviderChangeListener(l);

}


public void clickEvent(ActionEvent actionEvent) {


    try {
        JSONObject paramsMap = new JSONObject();
        paramsMap.put("userId", "1");


        HttpURLConnection httpURLConnection = null;
        try {
            URL url = new URL("http://ec2-54-226-57-153.compute-1.amazonaws.com:8080/#########");
            httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setReadTimeout(120000);
            httpURLConnection.setConnectTimeout(120000);
            httpURLConnection.setRequestMethod("POST");
            httpURLConnection.setRequestProperty("Content-Type", "application/json");
            httpURLConnection.setDoInput(true);
            httpURLConnection.setDoOutput(true);
            httpURLConnection.connect();
            OutputStream os = httpURLConnection.getOutputStream();
            BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(os, "UTF-8"));
            os.write(paramsMap.toString().getBytes());
            bufferedWriter.flush();
            bufferedWriter.close();
            os.close();

            if (httpURLConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                InputStream is = httpURLConnection.getInputStream();
                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
                StringBuilder builder = new StringBuilder();
                String line = bufferedReader.readLine();
                while (line != null) {
                    builder.append(line + "\n");
                    line = bufferedReader.readLine();
                }
                is.close();
                if (httpURLConnection != null)
                    httpURLConnection.disconnect();
                System.out.println(builder.toString());
                JSONObject json = new JSONObject(builder.toString());
                String status = json.optString("statusCode");
                String message = json.optString("message");
                String response = json.optString("response");
                System.out.println(status);
                System.out.println(message);
                //                                       System.out.println(response);
                JSONArray objarr = json.optJSONArray("response");
                Response[] temp_res = new Response[objarr.length()];

                for (int i = 0; i < objarr.length(); i++) {

                    System.out.println(objarr.getJSONObject(i));
                    JSONObject obj = objarr.getJSONObject(i);
                    String task = obj.optString("taskName");
                    taskId = obj.optString("taskId");
                    String taskType = obj.optString("taskType");
                    System.out.println(task);
                    System.out.println(taskId);
                    System.out.println(taskType);
                    temp_res[i] = new Response(taskId, taskType, task);


                }
                setRes(temp_res);


            } else {
                if (httpURLConnection != null)
                    httpURLConnection.disconnect();
                System.out.println("Invalid response from the server");
            }
        } catch (Exception e) {
            e.printStackTrace();
            if (httpURLConnection != null)
                httpURLConnection.disconnect();
        } finally {
            if (httpURLConnection != null)
                httpURLConnection.disconnect();
        }


    } catch (Exception e) {
        e.printStackTrace();
    }





}

公共类模型类{
私有字符串消息；
私有字符串状态码；
私有响应[]res=null；
受保护的瞬态PropertyChangeSupport _PropertyChangeSupport=新的PropertyChangeSupport（此）；
公共模型类（）{
超级（）；
单击事件（新建ActionEvent（））；
}
公共静态字符串taskId；
public void setTaskId（字符串taskId）{
系统输出打印（taskId）；
this.taskId=taskId；
}
公共字符串getTaskId（）{
返回taskId；
}
公共属性更改支持getPropertyChangeSupport（）{
返回属性更改支持；
}
公共无效设置消息（字符串消息）{
字符串oldMessage=this.message；
this.message=消息；
_propertyChangeSupport.firePropertyChange（“消息”，旧消息，消息）；
}
公共字符串getMessage（）{
返回消息；
}
公共无效设置状态代码（字符串状态代码）{
字符串oldStatusCode=this.statusCode；
this.statusCode=状态码；
_propertyChangeSupport.firePropertyChange（“状态码”，旧状态码，状态码）；
}
公共字符串getStatusCode（）{
返回状态码；
}
公共无效设置（响应[]设置）{
响应[]oldRes=this.res；
this.res=res；
系统输出打印项次（res）；
_propertyChangeSupport.firePropertyChange（“res”、oldRes、res）；
System.out.println（“此处刷新”）；
}
公共响应[]getRes（）{
返回res；
}
@凌驾
公共字符串toString（）{
返回“ClassPojo[response=“+res+”，message=“+message+”，statusCode=“+statusCode+”]”；
}
public void addPropertyChangeListener（PropertyChangeListener l）{
_addPropertyChangeListener（l）；
}
public void removePropertyChangeListener（PropertyChangeListener l）{
_propertyChangeSupport.removePropertyChangeListener（l）；
}
公众课堂反应{
私有字符串taskId；
私有字符串任务类型；
私有整数任务时间；
私有字符串taskName；
私有PropertyChangeSupport _PropertyChangeSupport=新PropertyChangeSupport（此）；
响应（字符串taskId、字符串taskType、字符串taskName）{
超级（）；
this.taskId=taskId；
this.taskType=taskType；
this.taskName=taskName；
}
public void setTaskId（字符串taskId）{
字符串oldTaskId=this.taskId；
this.taskId=taskId；
_FirePropertyChangeSupport.firePropertyChange（“taskId”，旧taskId，taskId）；
}
公共字符串getTaskId（）{
返回taskId；
}
公共void setTaskType（字符串taskType）{
字符串oldTaskType=this.taskType；
this.taskType=taskType；
_propertyChangeSupport.firePropertyChange（“taskType”，oldTaskType，taskType）；
}
公共字符串getTaskType（）{
返回任务类型；
}
public void setTaskTime（整数taskTime）{
整数oldTaskTime=this.taskTime；
this.taskTime=taskTime；
_propertyChangeSupport.firePropertyChange（“taskTime”，oldTaskTime，taskTime）；
}
公共整数getTaskTime（）{
返回任务时间；
}
public void setTaskName（字符串taskName）{
字符串oldstaskname=this.taskName；
this.taskName=taskName；
_propertyChangeSupport.firePropertyChange（“任务名”，旧任务名，任务名）；
}
公共字符串getTaskName（）{
返回任务名；
}
@凌驾
公共字符串toString（）{
返回“ClassPojo[taskId=“+taskId+”，taskType=“+taskType+”，taskTime=“+taskTime+
，taskName=“+taskName+”]；
}
public void addPropertyChangeListener（PropertyChangeListener l）{
_addPropertyChangeListener（l）；
}
public void removePropertyChangeListener（PropertyChangeListener l）{
_propertyChangeSupport.removePropertyChangeListener（l）；
}
}
受保护的瞬态ProviderChangeSupport ProviderChangeSupport=新ProviderChangeSupport（本）；
public void addProviderChangeListener（ProviderChangeListener l）{
providerChangeSupport.addProviderChangeListener（l）；
}
public void removeProviderChangeListener（ProviderChangeListener l）{
providerChangeSupport.removeProviderChangeListener（l）；
}
公共作废clickEvent（ActionEvent ActionEvent）{
试一试{
JSONObject paramsMap=新的JSONObject（）；
paramsMap.put（“userId”，“1”）；
HttpURLConnection HttpURLConnection=null；
试一试{
URL=新URL（“http://ec2-54-226-57-153.compute-1.amazonaws.com:8080/#########");
httpURLConnection=（httpURLConnection）url.openConnection（）；
httpURLConnection.setReadTimeout（120000）；
httpURLConnection.setConnectTimeout（120000）；
httpURLConnection.setRequestMethod（“POST”）；
setRequestProperty（“内容类型”、“应用程序/json”）；
httpURLConnection.setDoInput（true）；
httpURLConnection.setDoOutput（true）；
httpURLConnection.connect（）；
OutputStream os=httpURLConnection.getOutputStream（）；
BufferedWriter BufferedWriter=新的BufferedWriter（新的OutputStreamWriter（os，“UTF-8”））；
write（paramsMap.toString（）.getBytes（））；
bufferedWriter.flush（）；
bufferedWriter.close（）；
os.close（）；
if（httpURLConnection.getResponseCode（）==httpURLConnection.HTTP\u确定）{
InputStream=httpURLConnection.getInputStream（）；
BufferedReader BufferedReader=新的BufferedReader（新的InputStreamReader（即“UTF-8”）；
StringBuilder bu
res = (Response[]) res_new.toArray(new Response[res_new.size()]); 
setRes(res);

Response[] temp_res;
temp_res = (Response[]) res_new.toArray(new 
Response[res_new.size()]); 
setRes(temp_res);