動態地從json字符串創建和讀取樹數據結構

Question

我正在嘗試開發動態查詢構建器幾天。 但我在構建它時遇到了問題。

我正在復興的是像這樣的json。

{"category":"Case Law","query":{"AND":{"Year":{"having":"","exact":"","any":"","none":""},"AND":{"Report":{"having":"","exact":"","any":"","none":""},"Citation":{"having":"","exact":"","any":"","none":""}}}}}

這是以可讀的方式

Array
(
    [category] => Case Law
    [query] => Array
        (
            [OR] => Array
                (
                    [Year] => Array
                        (
                            [having] => some
                            [exact] => values
                            [any] => might
                            [none] => have
                        )

                    [AND] => Array
                        (
                            [Report] => Array
                                (
                                    [having] => 
                                    [exact] => 
                                    [any] => 
                                    [none] => 
                                )

                            [Citation] => Array
                                (
                                    [having] => 
                                    [exact] => 
                                    [any] => 
                                    [none] => 
                                )

                        )

                )

        )

)

• 這個json可以根據用戶輸入進行更改（可以有更多深度或更少）。
• 我正在嘗試做的是為apache lucene創建一個搜索查詢...（目前我們假設葉子值只是字符串。）

一定是這樣的（我需要什么）

（年份：另一個值OR（報告：一些valeus和引用：一些valeues））

我嘗試使用Jettison庫並使用DefaultMutableTreeNode來創建樹結構。 但它沒有像我預期的那樣工作。然后我嘗試了whit遞歸函數，它也沒有用

我想是否有可能創造這種東西。 如果是，該怎么做。

非常感謝您的嘗試！ 提前致謝。

Answer 1

好現在要求很明確，這是解決方案

定義您的運營

enum MyOperator {

  AND,
  OR

}

寫一個類來保持原子操作

class AtomicOperation {

   Object lhs;
   Object rhs;
   MyOperator operator;

}

現在，如果你想要的東西（年份：另一個價值觀或（報告：一些valeus和引用：一些valeues））

你的JSON應該是這樣的：

String jsonString = {{Year:['2001','2002']} OR {{Report:['Report1']} AND {Citation:['Citation1']}}}

所以首先使用代碼將此JSON轉換為AtominOperation類

ConvertJsonToObject.getFromJSON(jsonString,AtominOperation.class);

GSON will cast it to a Simple AtominOperation Object with operation "OR"
and lhs,rhs as 2 LinkedHashMaps (Default behaviour of GSON)

Now use the below method to get the proper AtomicOperation Object from the
above AtomicOperation Object.

public static AtomicOperation deriveFromJSON(AtomicOperation operation) {

        if (operation.getLhs().getClass().equals(LinkedHashMap.class)) {
            AtomicOperation leftOperation = deriveFromJSON(ConvertJsonToObject
                    .getFromJSON(ConvertJsonToObject.toJSON(operation.getLhs()),
                            AtomicOperation.class));
            AtomicOperation rightOperation = deriveFromJSON(ConvertJsonToObject
                    .getFromJSON(ConvertJsonToObject.toJSON(operation.getRhs()),
                            AtomicOperation.class));
            return new AtomicOperation(leftOperation, operation.getOperator(),
                    rightOperation);
        }
        return operation;

    }

最終的AtomicOperation對象將是您想要的。 :)

Answer 2

您查詢的JSON字符串

好。 這是我試過的。

（年份：另一個值OR（報告：一些valeus和引用：一些valeues和Field：另一個））

應該是這樣的：

String json = 
{"lhs":{"lhs":{"lhs":{"lhs":"Field","rhs":"Value","operator":"EQUAL_TO"},"rhs":{"lhs":"Citation","rhs":"Citation","operator":"EQUAL_TO"},"operator":"AND"},"rhs":{"lhs":"Report","rhs":"Report1","operator":"EQUAL_TO"},"operator":"AND"},"rhs":{"lhs":"Year","rhs":"2001","operator":"EQUAL_TO"},"operator":"OR"}

如果MYOperator枚舉是：

public enum MyOperator {

    AND,
    OR,
    EQUAL_TO {
    @Override
    public String toString() {
        return ":";
    }
},
    IN

}

和AtomicOperation是

public class AtomicOperation {


     Object lhs;
     Object rhs;
     MyOperator operator;

     AtomicOperation(Object lhs,MyOperator operator, Object rhs) {
         this.lhs = lhs;
         this.rhs = rhs;
         this.operator = operator;
     }

    public Object getLhs() {
        return lhs;
    }
    public void setLhs(Object lhs) {
        this.lhs = lhs;
    }
    public Object getRhs() {
        return rhs;
    }
    public void setRhs(Object rhs) {
        this.rhs = rhs;
    }
    public MyOperator getOperator() {
        return operator;
    }
    public void setOperator(MyOperator operator) {
        this.operator = operator;
    }

     @Override
public String toString() {
        return "(" + lhs.toString() + " " + operator.toString() + " " + rhs.toString() + ")"; 
}

}

然后，您可以使用以下代碼構建必要的AtomicOperation對象

AtomicOperation _r = deriveFromJSON(ConvertJsonToObject.getFromJSON(json,AtomicOperation.class));

下面是完整的ConvertJsonToObject類

public class ConvertJsonToObject {

    private static Gson gson = new GsonBuilder().create();

    public static final <T> T getFromJSON(String json, Class<T> clazz) {
        return gson.fromJson(json, clazz);
    }

    public static final <T> String toJSON(T clazz) {
        return gson.toJson(clazz);
    }
}

Answer 3

Use Something like Google Gson

class ConvertJsonToObject {

    private static Gson gson = new GsonBuilder().create();

    public static final <T> T getFromJSON(String json, Class<T> clazz) {
        return gson.fromJson(json, clazz);
    }

}

String jsonString = "{"category":"Case Law","query":{"AND":{"Year the case was instituted":{"having":"","exact":"","any":"","none":""},"AND":{"Report":{"having":"","exact":"","any":"","none":""},"Citation":{"having":"","exact":"","any":"","none":""}}}}}
"

Now you can use ConvertJsonToObject.getFromJSON(jsonString,Map.class);