Neo4j: custom parse string to POJO with jackson json

最新推荐文章于 2025-08-15 22:56:20 发布

ylzhjlinux

最新推荐文章于 2025-08-15 22:56:20 发布

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分类专栏： Neo4j 文章标签： json java

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本文介绍如何简化Neo4j客户端发送的JSON数据，并通过自定义序列化解析器来简化数据处理流程。通过调整POJO模型和引入Jackson JAXRS JSON提供者，实现客户端只需发送日期字符串或Unix时间戳，而无需明确包含所有日期字段。同时，展示如何创建一个自定义序列化解析器来将这些日期字符串转换为实际日期对象。最后，验证了此方法的有效性并通过示例代码进行了演示。

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In my project, I provide neo4j extentions to clients which send json string to extention while jackson auto parse the json string to my POJO Model. Howerver, I want to simply the json string sent by client .

The POJO Model class likes

@NodeEntity
@XmlRootElement
@JsonAutoDetect
@JsonIgnoreProperties(ignoreUnknown = true)
public class Task {
    @GraphId
    private Long nodeId;
    @Indexed(unique = true)
    private String taskId;

    @Indexed(indexType = IndexType.FULLTEXT, indexName = "TaskTile")
    private String title;
    @Indexed(indexType = IndexType.FULLTEXT, indexName = "TaskDescription")
    private String description;

    // Date startTime;
    // Date endTime;
    @Indexed
    private int startDate;
    @Indexed
    private int startTime;
    @Indexed
    private int endDate;
    @Indexed
    private int endTime;
---

The startDate, startTime,endDate,endTime adopted to search. I dont' want client to explict send these fields in json strings but send by two Date string likes yyyy-MM-dd HH:mm:ss or Unix time 172399299999.

The valueble hints are

http://wiki.fasterxml.com/JacksonHowToCustomDeserializers

http://magicmonster.com/kb/prg/java/spring/webmvc/jackson_custom.html

http://www.baeldung.com/jackson-deserialization

I did it by some post advices. But When I send some post, Neo4j Jersey actually doesn't use jackson to parse the string.

I tried everything I could. Finally, I tried it out.

In pom.xml, We add

 		<dependency>
			<groupId>com.fasterxml.jackson.jaxrs</groupId>
			<artifactId>jackson-jaxrs-json-provider</artifactId>
			<version>2.2.1</version>
		</dependency>

In Model , We delete

@XmlRootElement

and Change Json related annotations to

com.fasterxml.jackson.databind.annotation.*

not

org.codehaus.jackson.annotate.*

And The final Modle class is

import org.springframework.data.neo4j.annotation.GraphId;
import org.springframework.data.neo4j.annotation.Indexed;
import org.springframework.data.neo4j.annotation.Labels;
import org.springframework.data.neo4j.annotation.NodeEntity;
import org.springframework.data.neo4j.support.index.IndexType;

import com.fadeinfadeout.common.TaskDeserializer;
import com.fadeinfadeout.common.TaskPayOption;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;

@NodeEntity
@JsonDeserialize(using = TaskDeserializer.class )
public class Task {
    @GraphId
    private Long nodeId;
    @Indexed(unique = true)
    private String taskId;

The TaskDeserializer class is

package com.fadeinfadeout.common;

import java.io.IOException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.logging.Logger;

import com.fadeinfadeout.modle.Task;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.node.TextNode;

public class TaskDeserializer extends JsonDeserializer<Task> {
    private static DateFormat dateFormator = new SimpleDateFormat("yyyyMMdd");
    private static DateFormat timeFormator = new SimpleDateFormat("HHmmss");
    private static final Logger logger = Logger.getLogger(TaskDeserializer.class.getName());
    @Override
    public Task deserialize(JsonParser jp, DeserializationContext dc) throws IOException, JsonProcessingException {
	JsonNode node = jp.getCodec().readTree(jp);
	String taskId = ((TextNode) node.get("taskId")).textValue();
	String title = ((TextNode) node.get("title")).textValue();
	String description = ((TextNode) node.get("description")).textValue();

	String startTimeStr = ((TextNode) node.get("start")).textValue(); // unix time
	String endTimeStr = ((TextNode) node.get("end")).textValue();

	if (startTimeStr != null & endTimeStr != null) {
	    Date sdate = new Date(Long.valueOf(startTimeStr));
	    Date edate = new Date(Long.valueOf(endTimeStr));
	    int startDate = Integer.valueOf(dateFormator.format(sdate));
	    int startTime = Integer.valueOf(timeFormator.format(sdate));

	    int endDate = Integer.valueOf(dateFormator.format(edate));
	    int endTime = Integer.valueOf(timeFormator.format(edate));
	    return new Task(taskId, title, description, startDate, startTime, endDate, endTime);
	}

	return new Task(taskId, title, description);
    }
  
}

When post a request with

curl -i -H 'content-type: application/json' -X POST 
-d '{"taskId":"3","title":"打炮","description":"约吗",
"start":"1427965098585","end":"1427965598585"}' 
http://localhost:7474/fifo/task/addTask

The deserilizer result is correct