修改反映在本地参考中的类级别哈希图更改

Question

I am trying to save insurance details to database based on insuranceid or updating if the insuranceid is already exists in the database. The problem is that when I am trying to save multiple insurance details it is giving ConcurrentModificationException. While debugging I found that 1st cycle it is ok that is 1st insurance details is successfully saving to database. But when next insurance details is storing it is giving the Exception. Another thing is that here I am modifying main HashMap(patientId,HashMap(insuranceId,InsuranceInfo)), and the changes are reflecting in local reference that is the id is adding to insuranceMap variable in the current method(). Please try to help me

this is my storing method...

public void storeInsuranceInformationToDataBase(int patientId) throws SQLException
{
    //It gives arrayList of isuranceIds which are already in the data base.
    ArrayList<Integer> insuranceIdsListInDatabase = getInsuranceIdsListInDatabase();  

    //It returns HashMap of insurance ids for given patient id. 
    HashMap<Integer, InsuranceInfo> insuranceMap = getInsuranceDetails(patientId);   
    Set<Integer> insuranceIdsInHashMap = insuranceMap.keySet();

    //Here I am getting ConcurrentModificationException
    for (int insuranceIdInHashMap : insuranceIdsInHashMap)
    {
        //Here I am comparing the both ids..
        if (insuranceIdsListInDatabase.contains(insuranceIdInHashMap))  
        {
            String updateInsuranceQuery = "UPDATE jp_InsuranceInfo SET  typeOfPolicy='" + insuranceMap.get(insuranceIdInHashMap).getTypeOfPolicy() + "', amount=" + insuranceMap.get(insuranceIdInHashMap).getAmount() + ", duration=" + insuranceMap.get(insuranceIdInHashMap).getDuration()
                    + ", companyName='" + insuranceMap.get(insuranceIdInHashMap).getCompanyName() + "' WHERE insuranceId=" + insuranceIdInHashMap + ";";

            getDataBase().getStatement().executeUpdate(updateInsuranceQuery);
        }
        else
        {
            String insertInsuranceQuery = "INSERT INTO jp_InsuranceInfo VALUES(" + insuranceMap.get(insuranceIdInHashMap).getPatientId() + ",'" + insuranceMap.get(insuranceIdInHashMap).getTypeOfPolicy() + "'," + insuranceMap.get(insuranceIdInHashMap).getAmount() + ","
                    + insuranceMap.get(insuranceIdInHashMap).getDuration() + ",'" + insuranceMap.get(insuranceIdInHashMap).getCompanyName() + "')";

            getDataBase().getStatement().executeUpdate(insertInsuranceQuery);

            ResultSet generatedInsuranceId = getDataBase().getStatement().executeQuery("SELECT SCOPE_IDENTITY()");
            int newInsuranceId = 0;
            if (generatedInsuranceId.next())
            {
                newInsuranceId = generatedInsuranceId.getInt(1);
            }

            //Here it returns an insurance object which contains insurance details
            InsuranceInfo insuranceObject = insuranceMap.get(insuranceIdInHashMap); 
            insuranceObject.setInsuranceId(newInsuranceId);
            //Here I am trying to store the newly inserted insurance object into main hashmap
            storeInsuranceInfoToHashMap(patientId, insuranceObject);

            //I am removing previous insurance object with temporary insurance id
            getInsuranceMap().get(patientId).remove(insuranceIdInHashMap);

            // Adding newly generated insurance id to array list
            getInsuranceIdsListInDatabase().add(newInsuranceId);
        }
    }

Answer 1

Well, nothing strange. You trying to add a new item into the Map object while you're iterating through it.

My advise would be trying to save the insurance data you created when iterating through the Map into a temporary Map object. And, after you finished iterating the Map . Then, you could save the temporary map into the initial map.

example :

public void storeInsuranceInformationToDataBase(int patientId) throws SQLException
{
    //It gives arrayList of isuranceIds which are already in the data base.
    ArrayList<Integer> insuranceIdsListInDatabase = getInsuranceIdsListInDatabase();  

    //It returns HashMap of insurance ids for given patient id. 
    HashMap<Integer, InsuranceInfo> insuranceMap = getInsuranceDetails(patientId);   
    Map<Integer, InsuranceInfo> tempInsuranceMap = new HashMap<>();
    Set<Integer> insuranceIdsInHashMap = insuranceMap.keySet();

    //Here I am getting ConcurrentModificationException
    for (int insuranceIdInHashMap : insuranceIdsInHashMap)
    {
        //Here I am comparing the both ids..
        if (insuranceIdsListInDatabase.contains(insuranceIdInHashMap))  
        {
            String updateInsuranceQuery = "UPDATE jp_InsuranceInfo SET  typeOfPolicy='" + insuranceMap.get(insuranceIdInHashMap).getTypeOfPolicy() + "', amount=" + insuranceMap.get(insuranceIdInHashMap).getAmount() + ", duration=" + insuranceMap.get(insuranceIdInHashMap).getDuration()
                    + ", companyName='" + insuranceMap.get(insuranceIdInHashMap).getCompanyName() + "' WHERE insuranceId=" + insuranceIdInHashMap + ";";

            getDataBase().getStatement().executeUpdate(updateInsuranceQuery);
        }
        else
        {
            String insertInsuranceQuery = "INSERT INTO jp_InsuranceInfo VALUES(" + insuranceMap.get(insuranceIdInHashMap).getPatientId() + ",'" + insuranceMap.get(insuranceIdInHashMap).getTypeOfPolicy() + "'," + insuranceMap.get(insuranceIdInHashMap).getAmount() + ","
                    + insuranceMap.get(insuranceIdInHashMap).getDuration() + ",'" + insuranceMap.get(insuranceIdInHashMap).getCompanyName() + "')";

            getDataBase().getStatement().executeUpdate(insertInsuranceQuery);

            ResultSet generatedInsuranceId = getDataBase().getStatement().executeQuery("SELECT SCOPE_IDENTITY()");
            int newInsuranceId = 0;
            if (generatedInsuranceId.next())
            {
                newInsuranceId = generatedInsuranceId.getInt(1);
            }

            //Here it returns an insurance object which contains insurance details
            InsuranceInfo insuranceObject = insuranceMap.get(insuranceIdInHashMap); 
            insuranceObject.setInsuranceId(newInsuranceId);
            //Here I am trying to store the newly inserted insurance object into main hashmap
            storeInsuranceInfoToHashMap(patientId, insuranceObject); <-- make this function to save those information into the temporary map

            //I am removing previous insurance object with temporary insurance id
            getInsuranceMap().get(patientId).remove(insuranceIdInHashMap);

            // Adding newly generated insurance id to array list
            getInsuranceIdsListInDatabase().add(newInsuranceId);
        }
    }
    insuranceMap.putAll(tempInsuranceMap);
}