使用Jackson将Java对象转换为JSON [英] Converting Java objects to JSON with Jackson

问题描述

我希望我的JSON看起来像这样：

I want my JSON to look like this:

{
    "information": [{
        "timestamp": "xxxx",
        "feature": "xxxx",
        "ean": 1234,
        "data": "xxxx"
    }, {
        "timestamp": "yyy",
        "feature": "yyy",
        "ean": 12345,
        "data": "yyy"
    }]
}

到目前为止的代码：

import java.util.List;

public class ValueData {

    private List<ValueItems> information;

    public ValueData(){

    }

    public List<ValueItems> getInformation() {
        return information;
    }

    public void setInformation(List<ValueItems> information) {
        this.information = information;
    }

    @Override
    public String toString() {
        return String.format("{information:%s}", information);
    }

}

和

public class ValueItems {

    private String timestamp;
    private String feature;
    private int ean;
    private String data;


    public ValueItems(){

    }

    public ValueItems(String timestamp, String feature, int ean, String data){
        this.timestamp = timestamp;
        this.feature = feature;
        this.ean = ean;
        this.data = data;
    }

    public String getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(String timestamp) {
        this.timestamp = timestamp;
    }

    public String getFeature() {
        return feature;
    }

    public void setFeature(String feature) {
        this.feature = feature;
    }

    public int getEan() {
        return ean;
    }

    public void setEan(int ean) {
        this.ean = ean;
    }

    public String getData() {
        return data;
    }

    public void setData(String data) {
        this.data = data;
    }

    @Override
    public String toString() {
        return String.format("{timestamp:%s,feature:%s,ean:%s,data:%s}", timestamp, feature, ean, data);
    }
}

我只是错过了如何转换Java的部分杰克逊对JSON的反对：

I just missing the part how I can convert the Java object to JSON with Jackson:

public static void main(String[] args) {
   // CONVERT THE JAVA OBJECT TO JSON HERE
    System.out.println(json);
}

我的问题是：我的课程是否正确？我必须调用哪个实例以及如何实现此JSON输出？

My Question is: Are my classes correct? Which instance do I have to call and how that I can achieve this JSON output?

推荐答案

转换：

To convert your object in JSON with Jackson:

ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();
String json = ow.writeValueAsString(object);

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