无法在杰克逊中设置日期格式

Question

我在项目中使用Jackson lib，我希望以特定格式将数据存储在Mongo DB中。

TestQueries.java

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Iterator;
import java.util.TimeZone;
import java.util.regex.Pattern;

import org.jongo.MongoCollection;


public class TestQueries {

    public static void main(String[] args) {
        MyObj myObj = new MyObj();
        myObj.setDt(new Date());
        getCollection("testCollection").save(myObj);
        System.out.println("Created object");
        Iterator itr = getCollection("testCollection").find().as(MyObj.class).iterator();
        while(itr.hasNext()){
            System.out.println(((MyObj)itr.next()).getDt());
        }

    }

    private static Object getDate() {
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd/MM/yyyy");

        Date result = null;
        try {
            result = simpleDateFormat.parse("01/01/1900");
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return result;
    }

    private static MongoCollection getCollection(String documentName) {
        PlayJongo.openConnection();
        return PlayJongo.getCollection(documentName);
    }

}

我的POJO 的 MyObj.java

import java.io.Serializable;
import java.util.Date;


public class MyObj implements Serializable{
    private boolean isTrue;
    private boolean isFalse;
    private Date dt;
    /**
     * @return the isTrue
     */
    public boolean isTrue() {
        return isTrue;
    }
    /**
     * @param isTrue the isTrue to set
     */
    public void setTrue(boolean isTrue) {
        this.isTrue = isTrue;
    }
    /**
     * @return the isFalse
     */
    public boolean isFalse() {
        return isFalse;
    }
    /**
     * @param isFalse the isFalse to set
     */
    public void setFalse(boolean isFalse) {
        this.isFalse = isFalse;
    }
    /**
     * @return the dt
     */
    public Date getDt() {
        return dt;
    }
    /**
     * @param dt the dt to set
     */
    public void setDt(Date dt) {
        this.dt = dt;
    }

}

这是我的Service类，它使用Jongo

创建与mongo DB的连接

PlayJongo.java

import java.text.SimpleDateFormat;
import java.util.Date;

import org.jongo.Jongo;
import org.jongo.MongoCollection;
import org.jongo.marshall.jackson.JacksonMapper;
import org.jongo.marshall.jackson.JacksonMapper.Builder;

import com.fasterxml.jackson.core.Version;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.mongodb.DB;
import com.mongodb.MongoClient;
import com.mongodb.MongoClientOptions;
import com.mongodb.ServerAddress;

/**
 * Class used to establish connection to MongoDb using Jongo
 */
public class PlayJongo {
    private static MongoClient mongoClient = null;
    private static Jongo jongo = null;
    private final static Class LOGGING_CLASS = PlayJongo.class;
    //private static boolean debug = Logger.isAllowedToLog(PlayJongo.class.getCanonicalName());

    private PlayJongo(){

    }

    /**
     * Establishes connection with MongoDB if no connection already exists.
     */
    public static void openConnection() { 

        long startTime = System.currentTimeMillis();
        if (mongoClient == null) {
            try {
                String connectionUrl = "127.0.0.1";

                int connectionPort =27017;

                String dbName ="test_DB";

                MongoClientOptions options = MongoClientOptions
                        .builder()
                        .connectionsPerHost(20)
                        .autoConnectRetry(true).build();

                mongoClient = new MongoClient(new ServerAddress(connectionUrl, connectionPort), options);
                DB db = mongoClient.getDB(dbName);

                ObjectMapper objectMapper = new ObjectMapper();
                JsonSerializer<Object> ser = new ObjectToDate();
                objectMapper.setDateFormat(new SimpleDateFormat("dd/MM/yyyy HH:mm:sss aaa"));

                Builder builder = new JacksonMapper.Builder(objectMapper);
                jongo = new Jongo(db,builder.build());

            } catch (Exception e) {
                e.printStackTrace();
            }
        } else {
                System.out.println("Already eastablished");
        }
        long endTime = System.currentTimeMillis();

    }

    /**
     * Returns the MongoCollection with specified name
     * 
     * @param name
     * @return {@link MongoCollection}
     */
    public static MongoCollection getCollection(String name) {
        return jongo.getCollection(name);
    }

    /**
     * Used to close the Mongo Connection. Should be called only at application
     * shutdown.
     */
    public static void closeConnection() {
        long startTime = System.currentTimeMillis();
        try {
            mongoClient.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        long endTime = System.currentTimeMillis();
    }
}

我在PlayJongo.java中遇到错误，我试图在TestQueries.java文件中保存对象。

    Builder builder = new JacksonMapper.Builder(objectMapper);

，错误是，

Exception in thread "main" java.lang.IndexOutOfBoundsException
    at java.nio.Buffer.checkIndex(Unknown Source)
    at java.nio.HeapByteBuffer.get(Unknown Source)
    at org.bson.io.BSONByteBuffer.get(BSONByteBuffer.java:51)
    at org.bson.LazyBSONObject.sizeCString(LazyBSONObject.java:640)
    at org.bson.LazyBSONObject.getElement(LazyBSONObject.java:435)
    at org.bson.LazyBSONObject.get(LazyBSONObject.java:415)
    at com.mongodb.LazyWriteableDBObject.get(LazyWriteableDBObject.java:93)
    at org.jongo.Insert$LazyIdDBObject.get(Insert.java:105)
    at com.mongodb.DBCollection.save(DBCollection.java:1040)
    at org.jongo.Insert.save(Insert.java:49)
    at org.jongo.MongoCollection.save(MongoCollection.java:128)
    at TestQueries.main(TestQueries.java:21)

我在这里做错了吗？

我正在使用Jackson 2.5。