今天遇到了一个业务异常，实体类中的属性无法被反序列化成需要的相应的对象

2019-07-22 17:58:29,394  WARN [DecodeableRpcInvocation.java:112] :  [DUBBO] Decode argument failed: com.zoe.base.healthservice.api.po.healthmanager.CfgDoctorWorkTimePO.startTime: java.sql.Time cannot be assigned from null, dubbo version: 2.5.3, current host: 172.16.36.42
com.alibaba.com.caucho.hessian.io.HessianFieldException: com.zoe.base.healthservice.api.po.healthmanager.CfgDoctorWorkTimePO.startTime: java.sql.Time cannot be assigned from null
    at com.alibaba.com.caucho.hessian.io.JavaDeserializer.logDeserializeError(JavaDeserializer.java:677)
    at com.alibaba.com.caucho.hessian.io.JavaDeserializer$SqlTimeFieldDeserializer.deserialize(JavaDeserializer.java:656)
    at com.alibaba.com.caucho.hessian.io.JavaDeserializer.readObject(JavaDeserializer.java:233)
    at com.alibaba.com.caucho.hessian.io.JavaDeserializer.readObject(JavaDeserializer.java:157)
    at com.alibaba.com.caucho.hessian.io.Hessian2Input.readObjectInstance(Hessian2Input.java:2067)
    at com.alibaba.com.caucho.hessian.io.Hessian2Input.readObject(Hessian2Input.java:1592)
    at com.alibaba.com.caucho.hessian.io.Hessian2Input.readObject(Hessian2Input.java:1576)
    at com.alibaba.dubbo.common.serialize.support.hessian.Hessian2ObjectInput.readObject(Hessian2ObjectInput.java:94)
    at com.alibaba.dubbo.rpc.protocol.dubbo.DecodeableRpcInvocation.decode(DecodeableRpcInvocation.java:109)
    at com.alibaba.dubbo.rpc.protocol.dubbo.DecodeableRpcInvocation.decode(DecodeableRpcInvocation.java:71)
    at com.alibaba.dubbo.rpc.protocol.dubbo.DubboCodec.decodeBody(DubboCodec.java:137)
    at com.alibaba.dubbo.remoting.exchange.codec.ExchangeCodec.decode(ExchangeCodec.java:126)
    at com.alibaba.dubbo.remoting.exchange.codec.ExchangeCodec.decode(ExchangeCodec.java:87)
    at com.alibaba.dubbo.rpc.protocol.dubbo.DubboCountCodec.decode(DubboCountCodec.java:46)
    at com.alibaba.dubbo.remoting.transport.netty.NettyCodecAdapter$InternalDecoder.messageReceived(NettyCodecAdapter.java:134)
    at org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:80)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:564)
    at org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:559)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:274)
    at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:261)
    at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:349)
    at org.jboss.netty.channel.socket.nio.NioWorker.processSelectedKeys(NioWorker.java:280)
    at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:200)
    at org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108)
    at org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:44)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
    at com.alibaba.com.caucho.hessian.io.JavaDeserializer$SqlTimeFieldDeserializer.deserialize(JavaDeserializer.java:652)
    ... 26 more

事故现场还原

A模块调B模块的方法

first.png

package com.zoe.base.healthservice.api.po.healthmanager;

import java.sql.Time;
import java.util.*;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import org.hibernate.annotations.GenericGenerator;
import com.zoe.common.entity.BaseEntity;

/**
 * @date 2019/02/27
 */
@Entity
@Table(name = "cfg_doctor_work_time")
public class CfgDoctorWorkTimePO extends BaseEntity<CfgDoctorWorkTimePO>{

        /**
         *主键id
         */
        @Id
        @GeneratedValue(generator = "system-uuid")
        @GenericGenerator(name = "system-uuid", strategy = "uuid")
        @Column(name = "id")
        private String  id;

        /**
         *医生id
         */
        @Column(name = "doctor_id")
        private String  doctorId;

        /**
         *业务类型（胎心：fetal_heart）
         */
        @Column(name = "business_type")
        private String  businessType;

        /**
         *开始时间
         */
        @Column(name = "start_time")
        private Time startTime;

        /**
         *结束时间
         */
        @Column(name = "end_time")
        private Time  endTime;

        /**
         *创建时间
         */
        @Column(name = "create_time")
        private Date  createTime;

        /**
         *
         */
        @Column(name = "create_user")
        private String  createUser;

        /**
         *更新时间
         */
        @Column(name = "update_time")
        private Date  updateTime;

        /**
         *更新人
         */
        @Column(name = "update_user")
        private String  updateUser;

        /**
         *
         */
        @Column(name = "valid_flag")
        private Integer  validFlag;

        @Override
        public String getId() {
            return id;
        }
        public void setId(String id) {
            this.id = id;
        }

        public String getDoctorId() {
            return doctorId;
        }
        public void setDoctorId(String doctorId) {
            this.doctorId = doctorId;
        }

        public String getBusinessType() {
            return businessType;
        }
        public void setBusinessType(String businessType) {
            this.businessType = businessType;
        }

    public Time getStartTime() {
        return startTime;
    }

    public void setStartTime(Time startTime) {
        this.startTime = startTime;
    }

    public Time getEndTime() {
        return endTime;
    }

    public void setEndTime(Time endTime) {
        this.endTime = endTime;
    }

    public String getStartTimeStr(){
        Time startTime = this.getStartTime();

        return startTime.toString();
    }

    public String getEndTimeStr(){

        Time endTime = this.getEndTime();

        return endTime.toString();
    }

    public Date getCreateTime() {
            return createTime;
        }
        public void setCreateTime(Date createTime) {
            this.createTime = createTime;
        }

        public String getCreateUser() {
            return createUser;
        }
        public void setCreateUser(String createUser) {
            this.createUser = createUser;
        }

        public Date getUpdateTime() {
            return updateTime;
        }
        public void setUpdateTime(Date updateTime) {
            this.updateTime = updateTime;
        }

        public String getUpdateUser() {
            return updateUser;
        }
        public void setUpdateUser(String updateUser) {
            this.updateUser = updateUser;
        }

        public Integer getValidFlag() {
            return validFlag;
        }
        public void setValidFlag(Integer validFlag) {
            this.validFlag = validFlag;
        }

}

• 实体类继承Serilize示意图

sample.png

调用B模块后的执行结果

paramVo.png

为什么会出现这样的结果

根据异常我们定位到dubbo的源码

mark1.png

当我们反序列化之后，使用的是Hessian协议，且当反序列化的值为null的时候抛出异常

进一步回溯堆栈，看之前的报错

mark2.png

这是一个反序列化时间的类

 static class SqlTimeFieldDeserializer extends JavaDeserializer.FieldDeserializer {
        private final Field _field;

        SqlTimeFieldDeserializer(Field field) {
            this._field = field;
        }

        void deserialize(AbstractHessianInput in, Object obj) throws IOException {
            Time value = null;

            try {
                java.util.Date date = (java.util.Date)in.readObject();
                value = new Time(date.getTime());
                this._field.set(obj, value);
            } catch (Exception var5) {
                JavaDeserializer.logDeserializeError(this._field, obj, value, var5);
            }

        }
    }

他会将所有hessin协议传进来的Time对象都转成Date对象处理，所以传进来之前我们要对其进行初始化处理