package com.htzq.dbutil;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.List;
public class ModelToSqlConverter {
private Object model;
private List params, keyParams, modelList;
private String fieldNameString, questionMarkString, sqlString, conditionString, updateString;
private boolean update;
private String[] keys;
private Object[][] multiParams;
/**
* Initializes a newly created ModelToSqlConverter
*
* @param model The model representing the ASW file.
* @param keys The keys for locating the right row in ASW file.
*/
@SuppressWarnings( "unchecked")
public ModelToSqlConverter(Object model, String... keys){
this .model = model;
this .keys = keys;
params = new ArrayList();
keyParams = new ArrayList();
questionMarkString = "VALUES (";
fieldNameString = "(";
updateString = "";
conditionString = "WHERE ";
update = keys != null && keys.length > 0;
if (model instanceof List){
modelList = (List) model;
convertModelListToSqlAndParams();
} else {
convertModelToSqlAndParams();
}
}
/**
* Main method for Converting Model into SQL String and to value parameters.
*/
private void convertModelToSqlAndParams(){
for (Field field : model.getClass().getDeclaredFields()){
try {
field.setAccessible( true );
Object value = field.get(model);
String fieldName = field.getName();
if (value != null && !fieldName.equalsIgnoreCase("serialVersionUID")){
if (!update){
addQuestionMark();
addNameToSql(fieldName);
addValueToObjectArray(value);
} else {
if (isKey(fieldName)){
conditionString += fieldName + " = ?,";
keyParams.add(value);
} else {
addParamAndNameToSql(fieldName);
addValueToObjectArray(value);
}
}
}
} catch (IllegalArgumentException e){
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e){
// TODO Auto-generated catch block
e.printStackTrace();
}
}
sqlString = update ? getUpdateSql() : getInsertSql();
for (Object key : keyParams){
addValueToObjectArray(key);
}
}
/**
* Main method for Converting Model into SQL String and to value parameters.
*/
private void convertModelListToSqlAndParams(){
int row = 0;
boolean isKey = false ;
boolean firstModel = true ;
Field[] fields = modelList.get(0).getClass().getDeclaredFields();
multiParams = new Object[modelList.size()][fields.length];
for (Object model : modelList){
int col = 0;
keyParams = new ArrayList();
for (Field field : fields){
try {
field.setAccessible( true );
Object value = field.get(model);
String fieldName = field.getName();
if (value != null && !fieldName.equalsIgnoreCase("serialVersionUID")){
if (!update){
if (firstModel){
addQuestionMark();
addNameToSql(fieldName);
}
addValueToMultiParams(value, row, col);
} else {
isKey = isKey(fieldName);
if (isKey){
if (firstModel){
conditionString += fieldName + " = ?,";
}
keyParams.add(value);
} else {
if (firstModel)
addParamAndNameToSql(fieldName);
addValueToMultiParams(value, row, col);
}
}
}
} catch (IllegalArgumentException e){
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalAccessException e){
// TODO Auto-generated catch block
e.printStackTrace();
}
if (!isKey)
col ++;
}
firstModel = false ;
for (Object key : keyParams){
addValueToMultiParams(key, row, col);
col ++;
}
row ++;
}
sqlString = update ? getUpdateSql() : getInsertSql();
}
/**
* @param columnName
*/
private void addNameToSql(String columnName){
fieldNameString += columnName + ",";
}
/**
* @param value
*/
private void addValueToObjectArray(Object value){
params.add(value);
}
/**
* @param value
* @param row
* @param col
*/
private void addValueToMultiParams(Object value, int row, int col){
multiParams[row][col] = value;
}
public Object[][] getMultiValueParams(){
return removeNullsFromMultiArray(multiParams);
}
/**
* Adds question mark to string
*/
private void addQuestionMark(){
questionMarkString += "?,";
}
/**
* @param columnName
*/
private void addParamAndNameToSql(String columnName){
updateString += columnName + "= ?,";
}
/**
* @return the update SQL string.
*/
private String getUpdateSql(){
return updateString.substring(0, updateString.lastIndexOf(",")) + " " + conditionString.substring(0, conditionString.lastIndexOf(","));
}
/**
* @return the insert SQL string.
*/
private String getInsertSql(){
return fieldNameString.substring(0, fieldNameString.lastIndexOf(",")) + ") " + questionMarkString.substring(0, questionMarkString.lastIndexOf(","))
+ ")";
}
private Object[][] removeNullsFromMultiArray(Object[][] multiValuedArray){
for (int i = 0; i < multiValuedArray.length; i++){
ArrayList list = new ArrayList(); // creates a list to store the elements !=
// null
for (int j = 0; j < multiValuedArray[i].length; j++){
if (multiValuedArray[i][j] != null ){
list.add(multiValuedArray[i][j]); // elements != null will be added to the list.
}
}
multiValuedArray[i] = list.toArray(new Object[list.size()]); // all elements from list to an
// array.
}
return multiValuedArray;
}
/**
* Checks if the field name is a key.
*
* @param fieldName
* @return true if the field is a key.
*/
private boolean isKey(String fieldName){
boolean isKey = false ;
for (String key : keys){
if (fieldName.equalsIgnoreCase(key)){
isKey = true ;
}
}
return isKey;
}
/**
* @return the params
*/
public Object[] getParams(){
return params.toArray();
}
/**
* @return the sqlString
*/
public String getSqlString(){
return sqlString;
}
/**
* @param params the params to set
*/
public void setParams(List params){
this .params = params;
}
/**
* @param sqlString the sqlString to set
*/
public void setSqlString(String sqlString){
this .sqlString = sqlString;
}
}
