moparisthebest
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JdbcMapper
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JdbcMapper/beehive-jdbc-mapper/src/main/java/com/moparisthebest/jdbc/RowToObjectMapper.java

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package com.moparisthebest.jdbc;
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* $Header:$
*/
import java.lang.reflect.*;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.Calendar;
import java.util.HashMap;
import java.util.Map;
import static com.moparisthebest.jdbc.UpdateableDTO.YES;
import static com.moparisthebest.jdbc.UpdateableDTO.NO;
/**
* Map a ResultSet row to an Object. This mapper uses Java reflection to perform the mapping.
* <p/>
* This class is modified from org.apache.beehive.controls.system.jdbc.RowToObjectMapper
* <p/>
* The column names are compared, case insensitive, and with and without underscores (_), to the set* methods
* and fields of the given class to map the fields. For example:
* <p/>
* USERID would prefer method setUserId(), and fall back to field userId if the method doesn't exist
* USER_ID would act the same as the above, but also additionally try to match method setUser_Id(), or field user_id
* <p/>
* First, this class will look for a constructor that takes a ResultSet as a parameter, if it finds one, it will
* instantiate it with that constructor, sending in the ResultSet. Otherwise, this will only try to use public
* setters, but will set fields regardless of specified access, even private fields.
*
* @author Travis Burtrum (modifications from beehive)
*/
public class RowToObjectMapper<K, T> extends RowMapper<K, T> {
public static final int TYPE_BOOLEAN = _tmf.getTypeId(Boolean.TYPE);//TypeMappingsFactory.TYPE_BOOLEAN; // not public?
public static final int TYPE_BOOLEAN_OBJ = _tmf.getTypeId(Boolean.class);//TypeMappingsFactory.TYPE_BOOLEAN_OBJ; // not public?
protected boolean resultSetConstructor, constructorLoaded = false;
protected Constructor<? extends T> constructor;
protected final Class<? extends T> _returnTypeClass; // over-ride non-generic version of this in super class
// only non-null when _returnTypeClass is an array, or a map
protected final Class<?> componentType;
protected final boolean returnMap;
protected AccessibleObject[] _fields = null;
protected int[] _fieldTypes;
protected final Object[] _args = new Object[1];
public RowToObjectMapper(ResultSet resultSet, Class<T> returnTypeClass) {
this(resultSet, returnTypeClass, null, null);
}
public RowToObjectMapper(ResultSet resultSet, Class<T> returnTypeClass, Class<?> mapValType) {
this(resultSet, returnTypeClass, null, mapValType);
}
public RowToObjectMapper(ResultSet resultSet, Class<T> returnTypeClass, Calendar cal) {
this(resultSet, returnTypeClass, cal, null);
}
public RowToObjectMapper(ResultSet resultSet, Class<T> returnTypeClass, Calendar cal, Class<?> mapValType) {
this(resultSet, returnTypeClass, cal, mapValType, null);
}
/**
* Create a new RowToObjectMapper.
*
* @param resultSet ResultSet to map
* @param returnTypeClass Class to map to.
* @param cal Calendar instance for date/time mappings.
*/
public RowToObjectMapper(ResultSet resultSet, Class<T> returnTypeClass, Calendar cal, Class<?> mapValType, Class<K> mapKeyType) {
super(resultSet, returnTypeClass, cal, mapKeyType);
returnMap = Map.class.isAssignableFrom(returnTypeClass);
if(returnMap){
_returnTypeClass = ResultSetMapper.getConcreteClass(returnTypeClass, HashMap.class);
componentType = mapValType;
}else{
_returnTypeClass = returnTypeClass;
// detect if we want an array back
componentType = returnTypeClass.getComponentType();
}
}
protected void lazyLoadConstructor() {
if(constructorLoaded)
return;
// detect if returnTypeClass has a constructor that takes a ResultSet, if so, our job couldn't be easier...
boolean resultSetConstructor = false;
Constructor<? extends T> constructor = null;
try {
constructor = _returnTypeClass.getConstructor(ResultSet.class);
if (!constructor.isAccessible())
constructor.setAccessible(true);
resultSetConstructor = true;
} catch (Throwable e) {
// if no resultSetConstructor find the constructor
try {
constructor = _returnTypeClass.getDeclaredConstructor();
if (!constructor.isAccessible())
constructor.setAccessible(true);
} catch (Throwable e1) {
// if column count is 2 or less, it might map directly to a type like a Long or something, or be a map which does
// or if componentType is non-null, then we want an array like Long[] or String[]
if(_columnCount > 2 && componentType == null)
throw new MapperException("Exception when trying to get constructor for : "+_returnTypeClass.getName() + " Must have default no-arg constructor or one that takes a single ResultSet.", e1);
}
}
this.resultSetConstructor = resultSetConstructor;
this.constructor = constructor;
this.constructorLoaded = true;
}
/**
* This returns a new instance of the Map class required by Map<String, Object>[]
* It lives in it's own method to minimize suppressed warnings and allow subclasses to override methods,
* like perhaps to implement the original beehive behavior of case-insensitive strings
*/
@SuppressWarnings({"unchecked"})
protected Map<String, Object> getMapImplementation() throws IllegalAccessException, InstantiationException {
return (Map<String, Object>)_returnTypeClass.newInstance();
}
@Override
public K getMapKey() throws SQLException {
return this.extractColumnValue(1, _mapKeyType);
}
/**
* Do the mapping.
*
* @return An object instance.
*/
@SuppressWarnings({"unchecked"})
public T mapRowToReturnType() throws SQLException {
if(mapOnlySecondColumn)
return this.extractColumnValue(2, _returnTypeClass);
lazyLoadConstructor();
if (resultSetConstructor)
try {
return constructor.newInstance(_resultSet);
} catch (Throwable e) {
throw new MapperException(e.getClass().getName() + " when trying to create instance of : "
+ _returnTypeClass.getName() + " sending in a ResultSet object as a parameter", e);
}
if(returnMap) // we want a map
try {
final Map<String, Object> ret = getMapImplementation();
final ResultSetMetaData md = _resultSet.getMetaData();
final int columnLength = _columnCount+1;
if(componentType != null && componentType != Object.class){ // we want a specific value type
int typeId = _tmf.getTypeId(componentType);
for(int x = 1; x < columnLength; ++x)
ret.put(md.getColumnName(x).toLowerCase(), extractColumnValue(x, typeId));
} else // we want a generic object type
for(int x = 1; x < columnLength; ++x)
ret.put(md.getColumnName(x).toLowerCase(), _resultSet.getObject(x));
return _returnTypeClass.cast(ret);
} catch (Throwable e) {
throw new MapperException(e.getClass().getName() + " when trying to create a Map<String, "
+ (componentType == null ? "java.lang.Object" : componentType.getName()) + "> from a ResultSet row" +
", all columns must be of the map value type", e);
}
else if(componentType != null) // we want an array
try {
final Object ret = Array.newInstance(componentType, _columnCount);
final int typeId = _tmf.getTypeId(componentType);
for(int x = 0; x < _columnCount;)
Array.set(ret, x, extractColumnValue(++x, typeId));
//ret[x] = extractColumnValue(++x, typeId);
return _returnTypeClass.cast(ret);
} catch (Throwable e) {
throw new MapperException(e.getClass().getName() + " when trying to create a "
+ componentType.getName() + "[] from a ResultSet row, all columns must be of that type", e);
}
T resultObject = null;
// if the ResultSet only contains a single column we may be able to map directly
// to the return type -- if so we don't need to build any structures to support
// mapping
if (_columnCount == 1) {
final int typeId = _tmf.getTypeId(_returnTypeClass);
try {
if (typeId != TypeMappingsFactory.TYPE_UNKNOWN) {
return (T)extractColumnValue(1, typeId);
} else {
// we still might want a single value (i.e. java.util.Date)
Object val = extractColumnValue(1, typeId);
if (_returnTypeClass.isAssignableFrom(val.getClass())) {
return _returnTypeClass.cast(val);
}
}
} catch (Exception e) {
throw new MapperException(e.getMessage(), e);
}
}
if (_fields == null) {
try {
getFieldMappings();
} catch (SQLException e) {
throw new MapperException(e.getMessage(), e);
}
}
try {
resultObject = constructor.newInstance();
} catch (Throwable e) {
if(constructor == null) // then this is a different error
throw new MapperException("Exception when trying to get constructor for : "+_returnTypeClass.getName() + " Must have default no-arg constructor or one that takes a single ResultSet.", e);
throw new MapperException(e.getClass().getName() + " when trying to create instance of : "
+ _returnTypeClass.getName(), e);
}
for (int i = 1; i < _fields.length; i++) {
AccessibleObject f = _fields[i];
try {
_args[0] = extractColumnValue(i, _fieldTypes[i]);
//System.out.printf("field: '%s' obj: '%s' fieldType: '%s'\n", _fields[i], _args[0], _fieldTypes[i]);
// custom hacked-in support for enums, can do better when we scrap org.apache.beehive.controls.system.jdbc.TypeMappingsFactory
if(_fieldTypes[i] == 0 && _args[0] instanceof String){
Class<?> fieldType = f instanceof Field ? ((Field)f).getType() : ((Method)f).getParameterTypes()[0];
if(Enum.class.isAssignableFrom(fieldType))
_args[0] = Enum.valueOf((Class<? extends Enum>)fieldType, (String)_args[0]);
}
if (f instanceof Field) {
((Field) f).set(resultObject, _args[0]);
} else {
((Method) f).invoke(resultObject, _args);
}
} catch (SQLException e) {
throw new MapperException(e.getMessage(), e);
} catch (IllegalArgumentException iae) {
try {
ResultSetMetaData md = _resultSet.getMetaData();
if (f instanceof Field) {
throw new MapperException("The declared Java type for field " + ((Field) f).getName()
+ ((Field) f).getType().toString()
+ " is incompatible with the SQL format of column " + i + " '" + md.getColumnName(i)
+ "' (" + md.getColumnTypeName(i)
+ ") which returns objects of type " + _args[0].getClass().getName());
} else {
throw new MapperException("The declared Java type for method " + ((Method) f).getName()
+ ((Method) f).getParameterTypes()[0].toString()
+ " is incompatible with the SQL format of column " + i + " '" + md.getColumnName(i)
+ "' (" + md.getColumnTypeName(i)
+ ") which returns objects of type " + _args[0].getClass().getName());
}
} catch (SQLException e) {
throw new MapperException(e.getMessage(), e);
}
} catch (IllegalAccessException e) {
if (f instanceof Field) {
throw new MapperException("IllegalAccessException when trying to access field " + ((Field) f).getName(), e);
} else {
throw new MapperException("IllegalAccessException when trying to access method " + ((Method) f).getName(), e);
}
} catch (InvocationTargetException e) {
throw new MapperException("InvocationTargetException when trying to access method " + ((Method) f).getName(), e);
}
}
// if this resultObject is Finishable, call finish()
if (resultObject instanceof Finishable)
try {
((Finishable) resultObject).finish(_resultSet);
} catch (SQLException e) {
throw new MapperException(e.getMessage(), e);
}
return resultObject;
}
/**
* Provided so we can extract a column value to use for the key of a map
*
* @param index
* @param classType
* @return
* @throws SQLException
*/
@SuppressWarnings({"unchecked"})
public <E> E extractColumnValue(int index, Class<E> classType) throws SQLException {
return classType.cast(extractColumnValue(index, _tmf.getTypeId(classType)));
}
/**
* Build the structures necessary to do the mapping
*
* @throws SQLException on error.
*/
protected void getFieldMappings()
throws SQLException {
final String[] keys = getKeysFromResultSet();
//System.out.println("keys: "+ Arrays.toString(keys));
// added this to handle stripping '_' from keys
Map<String, String> strippedKeys = new HashMap<String, String>();
for (final String key : keys) {
String strippedKey = key;
if (key != null) {
strippedKey = key.replaceAll("_", "");
if (key.equals(strippedKey))
continue;
strippedKeys.put(strippedKey, key);
}
}
//System.out.println("strippedKeys: "+strippedKeys);
//
// find fields or setters for return class
//
HashMap<String, AccessibleObject> mapFields = new HashMap<String, AccessibleObject>(_columnCount * 2);
for (int i = 1; i <= _columnCount; i++) {
mapFields.put(keys[i], null);
}
// public methods
Method[] classMethods = _returnTypeClass.getMethods();
for (Method m : classMethods) {
//System.out.printf("method: '%s', isSetterMethod: '%s'\n", m, isSetterMethod(m));
if (isSetterMethod(m)) {
String fieldName = m.getName().substring(3).toUpperCase();
//System.out.println("METHOD-fieldName1: "+fieldName);
if (!mapFields.containsKey(fieldName)) {
fieldName = strippedKeys.get(fieldName);
if (fieldName == null)
continue;
//System.out.println("METHOD-fieldName2: "+fieldName);
}
final AccessibleObject field = mapFields.get(fieldName);
// check for overloads
if (field == null) {
mapFields.put(fieldName, m);
} else {
// fix for 'overloaded' methods when it comes to stripped keys, we want the exact match
final String thisName = m.getName().substring(3).toUpperCase();
final String previousName = ((Method) field).getName().substring(3).toUpperCase();
//System.out.printf("thisName: '%s', previousName: '%s', mapFields.containsKey(thisName): %b, strippedKeys.containsKey(previousName): %b\n", thisName, previousName, mapFields.containsKey(thisName), strippedKeys.containsKey(previousName));
if(mapFields.containsKey(thisName) && strippedKeys.containsKey(previousName)) {
mapFields.put(fieldName, m);
} else if (!mapFields.containsKey(previousName) || !strippedKeys.containsKey(thisName)) {
throw new MapperException("Unable to choose between overloaded methods '" + m.getName()
+ "' and '" + ((Method) field).getName() + "' for field '" + fieldName + "' on the '" + _returnTypeClass.getName() + "' class. Mapping is done using "
+ "a case insensitive comparison of SQL ResultSet columns to field "
+ "names and public setter methods on the return class. Columns are also "
+ "stripped of '_' and compared if no match is found with them.");
}
// then the 'overloaded' method is already correct
}
}
}
// fix for 8813: include inherited and non-public fields
for (Class clazz = _returnTypeClass; clazz != null && clazz != Object.class; clazz = clazz.getSuperclass()) {
//System.out.println("searching for fields in class: "+clazz.getName());
Field[] classFields = clazz.getDeclaredFields();
//System.out.println("fields in class: "+Arrays.toString(classFields));
for (Field f : classFields) {
if (Modifier.isStatic(f.getModifiers())) continue;
//if (!Modifier.isPublic(f.getModifiers())) continue; // commented this out to work on all types of fields
String fieldName = f.getName().toUpperCase();
//System.out.println("fieldName: "+fieldName);
if (!mapFields.containsKey(fieldName)) {
fieldName = strippedKeys.get(fieldName);
if (fieldName == null)
continue;
}
final AccessibleObject field = mapFields.get(fieldName);
if (field == null) {
mapFields.put(fieldName, f);
} else if(field instanceof Field) {
// fix for 'overloaded' fields when it comes to stripped keys, we want the exact match
final String thisName = f.getName().toUpperCase();
final String previousName = ((Field) field).getName().toUpperCase();
//System.out.printf("thisName: '%s', previousName: '%s', mapFields.containsKey(thisName): %b, strippedKeys.containsKey(previousName): %b\n", thisName, previousName, mapFields.containsKey(thisName), strippedKeys.containsKey(previousName));
if(mapFields.containsKey(thisName) && strippedKeys.containsKey(previousName)) {
mapFields.put(fieldName, f);
} else if (!mapFields.containsKey(previousName) || !strippedKeys.containsKey(thisName)) {
throw new MapperException("Unable to choose between overloaded fields '" + f.getName()
+ "' and '" + ((Field) field).getName() + "' for field '" + fieldName + "' on the '" + _returnTypeClass.getName() + "' class. Mapping is done using "
+ "a case insensitive comparison of SQL ResultSet columns to field "
+ "names and public setter methods on the return class. Columns are also "
+ "stripped of '_' and compared if no match is found with them.");
}
// then the 'overloaded' field is already correct
}
}
}
// finally actually init the fields array
_fields = new AccessibleObject[_columnCount + 1];
_fieldTypes = new int[_columnCount + 1];
for (int i = 1; i < _fields.length; i++) {
AccessibleObject f = mapFields.get(keys[i]);
if (f == null) {
throw new MapperException("Unable to map the SQL column '" + keys[i]
+ "' to a field on the '" + _returnTypeClass.getName() +
"' class. Mapping is done using a case insensitive comparison of SQL ResultSet "
+ "columns to field "
+ "names and public setter methods on the return class. Columns are also "
+ "stripped of '_' and compared if no match is found with them.");
}
f.setAccessible(true);
_fields[i] = f;
if (f instanceof Field) {
_fieldTypes[i] = _tmf.getTypeId(((Field) f).getType());
} else {
_fieldTypes[i] = _tmf.getTypeId(((Method) f).getParameterTypes()[0]);
}
}
}
@Override
protected Object extractColumnValue(int index, int resultType) throws SQLException {
try{
if (resultType != TYPE_BOOLEAN && resultType != TYPE_BOOLEAN_OBJ)
return super.extractColumnValue(index, resultType);
else {
// do some special handling to convert a database string to a boolean
boolean ret;
try {
// try to get an actual boolean from the database
ret = _resultSet.getBoolean(index);
// null seems to get returned as false above, so String code won't run if its null
if (_resultSet.wasNull())
if (resultType == TYPE_BOOLEAN_OBJ)
return null; // only return null for Boolean object
else
throw new MapperException(String.format("Implicit conversion of database string to boolean failed on column '%d'. Returned string needs to be 'Y' or 'N' and was instead 'null'. If you want to accept null values, make it an object Boolean instead of primitive boolean.", index));
} catch (SQLException e) {
// if we are here, it wasn't a boolean or null, so try to grab a string instead
String bool = _resultSet.getString(index);//.toUpperCase(); // do we want it case-insensitive?
ret = YES.equals(bool);
if (!ret && !NO.equals(bool))
throw new MapperException(String.format("Implicit conversion of database string to boolean failed on column '%d'. Returned string needs to be 'Y' or 'N' and was instead '%s'.", index, bool));
//throw e;
}
return ret ? Boolean.TRUE : Boolean.FALSE;
}
}catch(SQLException e){
throw new SQLExceptionColumnNum(e, index);
}
}
public static <T> T fixNull(Class<T> returnType) {
return returnType.cast(_tmf.fixNull(returnType));
}
}
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