CustomerEntity.java

package com.mageddo;

import org.hibernate.annotations.Type;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Table(name = "CUSTOMER")
@Entity
public class TempEntity {

    private Integer id;
    public String json;

    @Column(name = "JSN_DETAILS")
    @Type(type = "com.mageddo.JsonBType")
    public String getJson() {
        return json;
    }

    public TempEntity setJson(String json) {
        this.json = json;
        return this;
    }

    @Id
    @Column(name = "IDT_CUSTOMER")
    public Integer getId() {
        return id;
    }

    public TempEntity setId(Integer id) {
        this.id = id;
        return this;
    }
}

CustomerJMX.java

package com.mageddo;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jmx.export.annotation.ManagedOperation;
import org.springframework.jmx.export.annotation.ManagedResource;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;

@Component
@ManagedResource
public class TempJMX {

    @Autowired
    private TempDao tempDao;

    @Transactional
    @ManagedOperation
    public void create(){
        tempDao.create(new TempEntity().setId((int) System.currentTimeMillis()).setJson("{}"));
    }

    @Transactional
    @ManagedOperation
    public String find(int id) throws JsonProcessingException {
        return new ObjectMapper().enable(SerializationFeature.INDENT_OUTPUT).writeValueAsString(tempDao.find(id));
    }
}

JsonBType.java

package com.mageddo;

import org.hibernate.HibernateException;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.type.StandardBasicTypes;
import org.hibernate.usertype.EnhancedUserType;
import org.postgresql.util.PGobject;

import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import java.util.Objects;

public class JsonBType implements EnhancedUserType, Serializable {

    @Override
    public int[] sqlTypes() {
        return new int[]{Types.VARCHAR};
    }

    @Override
    public Class returnedClass() {
        return String.class;
    }

    @Override
    public boolean equals(Object x, Object y) throws HibernateException {
        return Objects.equals(x, y);
    }

    @Override
    public int hashCode(Object o) throws HibernateException {
        return Objects.hashCode(o);
    }

    @Override
    public Object nullSafeGet(
        ResultSet rs, String[] names, SessionImplementor session, Object owner
    ) throws HibernateException, SQLException {
        final PGobject o = (PGobject) rs.getObject(names[0]);
        return o.getValue();
    }

    @Override
    public void nullSafeSet(
        PreparedStatement stm, Object value, int index, SessionImplementor session
    ) throws HibernateException, SQLException {
        if (value == null) {
            stm.setNull(index, Types.OTHER);
        } else {
            stm.setObject(index, value, Types.OTHER);
        }
    }

    @Override
    public Object deepCopy(Object value) throws HibernateException {
        return value;
    }

    @Override
    public boolean isMutable() {
        return false;
    }

    @Override
    public Serializable disassemble(Object value) throws HibernateException {
        return (Serializable) value;
    }

    @Override
    public Object assemble(Serializable cached, Object value) throws HibernateException {
        return cached;
    }

    @Override
    public Object replace(Object original, Object target, Object owner) throws HibernateException {
        return original;
    }

    @Override
    public String objectToSQLString(Object object) {
        throw new UnsupportedOperationException();
    }

    @Override
    public String toXMLString(Object o) {
        return o == null ? null : String.valueOf(o);
    }

    @Override
    public Object fromXMLString(String str) {
        return str;
    }

}