如何创建自定义的Jackson映射器?

i want build a DataTable for google charts with jackson that i can easily create a json file..

我想用jackson为谷歌图表构建一个可以轻松创建json文件的数据表。

i use this jackson version:

我使用杰克逊版本:

<dependency>
   <groupId>com.fasterxml.jackson.core</groupId>
   <artifactId>jackson-databind</artifactId>
   <version>2.2.3</version>
</dependency>

I have the following classes (The example creates only rows at the moment):

我有以下的类(这个例子现在只创建行):

 public class DataTable implements Serializable {

    private static final long serialVersionUID = 1L;

    @JsonProperty("rows")   
    private List<DataTableRow> dataTableRows;


    public List<DataTableRow> getDataTableRows() {      
       return dataTableRows;    
    }

    public void setDataTableRows(List<DataTableRow> dataTableRows) {
        this.dataTableRows = dataTableRows;     
    }   

 }

then i have a DataTableRow Class

然后我有一个DataTableRow类

public class DataTableRow implements Serializable{

    private static final long serialVersionUID = 1L;    

    @JsonProperty("c")  
    List<SingleTableCell> singleTableCell;

    public List<SingleTableCell> getSingleTableCell() {         
        return singleTableCell;     
    }

    public void setSingleTableCell(List<SingleTableCell> singleTableCell) {         
        this.singleTableCell = singleTableCell;     
    }   

}

and a row has several SingleTableCells

一排有几个单排

public class SingleTableCell implements Serializable{

    private static final long serialVersionUID = 1L;    

    @JsonProperty("v")  
    private Value value;

    @JsonProperty("f")  
    private String formattedValue = null;


    public Value getValue() {       
        return value;   
    }


    public void setValue(Value value) {         
        this.value = value;     
    }


    public String getFormattedValue() {         
        return formattedValue;  
    }


    public void setFormattedValue(String formattedValue) {
        this.formattedValue = formattedValue;   
   }

}

this generates me a Json String like this :

这会生成一个Json字符串，如下所示:

{

"rows": [
    {
        "c": [
            {
                "v": {
                    "value": "Hans"
                },
                "f": null
            },
            {
                "v": {
                    "value": 3.4
                },
                "f": null
            }
        ]
    }
]

}

the Problem is my Value object this is an abstract class i want not that this class is rendering as a json object i want only a key value pair! so it should not render to this:

问题是我的值对象这是一个抽象类我不想这个类呈现为json对象我只想要一个键值对!因此，它不应该这样说:

"v": { "value": "Hans" }

"v": {"value": "Hans"}

i want only this: "v" : "Hans"

我只想要这个:"v": "汉斯"

and i want that i can define how the Value object is rendert the value object cann be for example a String,Double or Date Object... if it is a Date object the Date should transformed to a String like this: "v" : Date(2010,10,01)

我想定义Value对象是如何渲染Value对象可以是字符串，Double或Date对象。如果它是一个日期对象，那么日期应该转换为如下字符串:“v”:Date(2010、10、01)

and if it is an other Object like a String or Double i want decide how the json string looks like..

如果它是另一个对象，比如字符串或者Double，我想要决定json字符串的样子

my abstract class looks like this:

我的抽象类是这样的:

public abstract class Value { 

}

public class StringValue extends Value{

    String Value;
}



public class DoubleValue extends Value{

    Double Value; 
}


public class DateValue extends Value{

    Date Value;
}

1 个解决方案

#1

I would make the following changes to your code in order to achieve what you want:

我将对您的代码做如下修改，以实现您的目标:

public abstract class Value { 

}

public class StringValue extends Value{

    @JsonValue
    //do whatever else you need although I can't really see what that would be
    String Value;
}



public class DoubleValue extends Value{

    @JsonValue
    //do whatever else you need although I can't really see what that would be
    Double Value; 
}


public class DateValue extends Value{

    @JsonValue
    @DateFormat() //insert the relevant date code here
    Date Value;

}

From the code you have posted I cannot really see what the purpose of class Value is, but I ran with here since I am guessing you are doing more with it than you have posted

从您所发布的代码中，我无法真正理解类值的目的是什么，但是我在这里使用了它，因为我猜您使用它所做的事情比您发布的要多

#1