Question

我有任务列表。当我删除我的任务之一时，我的列表仍然显示列表中的任务但在服务器端我已更新列表我无法刷新列表。我从服务器获取新的任务数组但无法显示它。当我再次启动我的应用程序时，它显示更新的列表。如何在不杀死应用程序的情况下获取更新列表？我已更新数组但无法在视图上显示它的时间。

    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();
    }





}

Answer 1

我认为您需要添加providerChangeSupport.fireProviderRefresh("res"); 并且您必须为providerChangeSupport创建公共方法。这是链接：https://community.oracle.com/message/13203364#13203364

Answer 2

除了Rashi Verma建议的解决方案外，还需要进行一项更改。

代码段：

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

需要更改为：

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

目前，由于在调用setRes之前更改了res的值，因此不会在setRes中触发propertyChangeEvent。这个propertyChangeEvent和providerRefresh都需要用于开始在UI上反映的更改。

如何在oracle maf中更新/刷新列表视图的列表项？

2 个答案: