Question

我想使用Java从分类视图创建一个Json String，但是我无法让Json子类保持在父级之下。我保持以下输出：

{“identifier”：“id”，“label”：“State”，“items”：[

会知道从2级分类视图生成JSON字符串是否可行，或者是否有更好的方法来实现它。

下面是我的java方法：

public ResponseWriter getJSONData() { 
        long startTime = System.currentTimeMillis();
        FacesContext facesContext = FacesContext.getCurrentInstance();
        ResponseWriter resWriter = facesContext.getResponseWriter();

        //StringWriter stringOut = new StringWriter();
        JsonWriter writer = new JsonWriter(resWriter,false);
        Database db = null;

        try {
            writer.startObject();

            writer.startProperty("identifier");
            writer.outStringLiteral("id");
            writer.endProperty();

            writer.startProperty("label");
            writer.outStringLiteral("State");
            writer.endProperty();

            writer.startProperty("items");
            writer.startArray();

            db = DominoUtils.getCurrentSession().getCurrentDatabase();
            View lookupDB = db.getView("StateAndCity");         
            //Document doc = lookupDB.getFirstDocument();   

            ViewNavigator nav = lookupDB.createViewNav();
            ViewEntry ve = nav.getFirst();

            boolean run =false;
            while (ve != null){    
                counter++;
                Vector cv = ve.getColumnValues();
                int level = ve.getIndentLevel();
                String levelTitle = (String) cv.get(level);


                writer.startArrayItem();
                writer.startObject();

                if (ve.isCategory()) {

                    if (run) {
                        writer.endArrayItem();
                        writer.endArray();

                    } 
                    run= true;
                    writer.startArrayItem();

                    writer.startProperty("id"); 
                    writer.outStringLiteral(getID());
                    writer.endProperty();

                    writer.startProperty("title");
                    writer.outStringLiteral(levelTitle);
                    writer.endProperty();

                    writer.startProperty("category");
                    writer.outStringLiteral("true");
                    writer.endProperty();

                    writer.startProperty("children");
                    writer.startArray();

                }else{

                    writer.startArrayItem();
                    writer.startObject();

                    Document doc = ve.getDocument();


                    writer.startProperty("id"); 
                    writer.outStringLiteral(getID());
                    writer.endProperty();

                    writer.startProperty("docId"); 
                    writer.outStringLiteral(doc.getUniversalID());
                    writer.endProperty();

                    writer.startProperty("title");
                    writer.outStringLiteral(levelTitle);
                    writer.endProperty();

                    writer.startProperty("category");
                    writer.outStringLiteral("false");
                    writer.endProperty();

                    writer.endObject();
                    writer.endArrayItem();

                }    


                ViewEntry tmpentry = nav.getNext();

                ve.recycle();
                ve = tmpentry;
            }  

            writer.endArray();
            writer.endProperty();
            writer.endObject();


            long endTime   = System.currentTimeMillis();
            long totalTime = endTime - startTime;
            //System.out.println("running time:  "+totalTime);

            writer.flush();


            return resWriter;

        }catch (NotesException e) {

            e.printStackTrace();
        }
        return resWriter;
    }

更新想使用我的返回JSON来创建以下类型的网格，但具有两个级别类别State和City

JSON输出

{
    "identifier": "id",
    "label": "name",
    "items": [{
        "id": "AK",
        "type": "state",
        "state": "AK",
        "childItems": [{
            "id": "Anchorage",
            "type": "city",
            "city": "Anchorage",
            "numPeople": "2",
            "childItems": [{
                    "id": "B3093953178C98E905257838007ABC48",
                    "firstname": "Bella",
                    "lastname": "Martin",
                    "valueToAdd": "2"
                },
                {
                    "id": "7FDB9CCDE7D6923E05257838007ABC1E",
                    "firstname": "Brian",
                    "lastname": "Leggett",
                    "valueToAdd": "2"
                }
            ]
        }]

....
    }]
}

Answer 1

你可以回归“旧的”多米诺骨牌技巧并取消所有Java。将视图定义为Passthru HTML并使用mime类型“text / Json”创建“$$ ViewTemplate for ViewName”表单。然后，您可以使用？Openview访问输出。根据需要喷洒Json标记。

或者只使用... / viewname？ReadviewEntries＆amp; Outputformat = json

构建Json输出

Answer 2

看起来您的代码在写入任何内容之前就崩溃了。有一些问题陈述：

矢量/数组是基于零的，但int level = ve.getIndentLevel();不是，所以你最有可能得到索引超出范围的错误
如果某些内容返回null，则转换为String也会出错。所以将String levelTitle = (String) cv.get(level);更改为String levelTitle = String.valueOf(cv.get(level));
我建议您将方法签名更改为public String getJSONFromView(final Database db, final String viewName) {...}之类的内容然后使用一些包装代码来调用该方法。这允许您在Domino命令行应用程序中使用该类，这在本地的Designer / Eclipse中进行调试非常方便。由于该类没有XPage依赖，使生活更轻松。我开发了所有VoP：核心没有服务器，只有Notes类依赖。您将创建一个这样的测试类（省略错误处理）：
```
public class Test1 {
   public static void main(String args[]) {
       NotesThread.sinitThread();
       Session s = NotesFactory.createSession();
       Database db = s.openDatabase("someserver","somedb");
       Yourclass yc = new Yourclass();
       System.out.println(yc.getJSONFromView(db,"viewname");
       db.recycle();
       s.recycle();
       NotesThread.stermThread();
   }
}
```

您可能需要在Domino设计器中切换到Java透视图并创建一个标准Java项目。这应该允许您在XPage中使用Java类之前使其成为您想要的。

我写了类似的东西，你可以check it out。

让我们知道需要澄清的内容。

XPages：从分类视图

2 个答案: