cn.featherfly.persistence.jdbc.BeanPropertyRowMapper Maven / Gradle / Ivy
package cn.featherfly.persistence.jdbc;
import java.beans.PropertyDescriptor;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.BeanWrapper;
import org.springframework.beans.NotWritablePropertyException;
import org.springframework.beans.PropertyAccessorFactory;
import org.springframework.beans.TypeMismatchException;
import org.springframework.dao.DataRetrievalFailureException;
import org.springframework.dao.InvalidDataAccessApiUsageException;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import cn.featherfly.common.bean.BeanDescriptor;
import cn.featherfly.common.bean.BeanProperty;
import cn.featherfly.common.db.JdbcException;
import cn.featherfly.common.db.JdbcUtils;
/**
*
* BeanPropertyRowMapper
* 类的说明放这里
*
*
* @author 钟冀
*/
public class BeanPropertyRowMapper implements RowMapper {
/** Logger available to subclasses */
protected final Log logger = LogFactory.getLog(getClass());
/** The class we are mapping to */
private Class mappedClass;
/** Whether we're strictly validating */
private boolean checkFullyPopulated = false;
/** Whether we're defaulting primitives when mapping a null value */
private boolean primitivesDefaultedForNullValue = false;
/** Map of the fields we provide mapping for */
private Map mappedFields;
/** Set of bean properties we provide mapping for */
private Set mappedProperties;
/**
* Create a new BeanPropertyRowMapper, accepting unpopulated properties
* in the target bean.
* Consider using the {@link #newInstance} factory method instead,
* which allows for specifying the mapped type once only.
* @param mappedClass the class that each row should be mapped to
*/
public BeanPropertyRowMapper(Class mappedClass) {
initialize(mappedClass);
}
/**
* Create a new BeanPropertyRowMapper.
* @param mappedClass the class that each row should be mapped to
* @param checkFullyPopulated whether we're strictly validating that
* all bean properties have been mapped from corresponding database fields
*/
public BeanPropertyRowMapper(Class mappedClass, boolean checkFullyPopulated) {
initialize(mappedClass);
this.checkFullyPopulated = checkFullyPopulated;
}
/**
* Initialize the mapping metadata for the given class.
* @param mappedClass the mapped class.
*/
protected void initialize(Class mappedClass) {
this.mappedClass = mappedClass;
this.mappedFields = new HashMap();
this.mappedProperties = new HashSet();
PropertyDescriptor[] pds = BeanUtils.getPropertyDescriptors(mappedClass);
for (PropertyDescriptor pd : pds) {
if (pd.getWriteMethod() != null) {
this.mappedFields.put(pd.getName().toLowerCase(), pd);
String underscoredName = underscoreName(pd.getName());
if (!pd.getName().toLowerCase().equals(underscoredName)) {
this.mappedFields.put(underscoredName, pd);
}
this.mappedProperties.add(pd.getName());
}
}
}
/**
* Convert a name in camelCase to an underscored name in lower case.
* Any upper case letters are converted to lower case with a preceding underscore.
* @param name the string containing original name
* @return the converted name
*/
private String underscoreName(String name) {
if (!StringUtils.hasLength(name)) {
return "";
}
StringBuilder result = new StringBuilder();
result.append(name.substring(0, 1).toLowerCase());
for (int i = 1; i < name.length(); i++) {
String s = name.substring(i, i + 1);
String slc = s.toLowerCase();
if (!s.equals(slc)) {
result.append("_").append(slc);
}
else {
result.append(s);
}
}
return result.toString();
}
/**
* Get the class that we are mapping to.
*/
public final Class getMappedClass() {
return this.mappedClass;
}
/**
* Set whether we're strictly validating that all bean properties have been
* mapped from corresponding database fields.
* Default is {@code false}, accepting unpopulated properties in the
* target bean.
*/
public void setCheckFullyPopulated(boolean checkFullyPopulated) {
this.checkFullyPopulated = checkFullyPopulated;
}
/**
* Return whether we're strictly validating that all bean properties have been
* mapped from corresponding database fields.
*/
public boolean isCheckFullyPopulated() {
return this.checkFullyPopulated;
}
/**
* Set whether we're defaulting Java primitives in the case of mapping a null value
* from corresponding database fields.
*
Default is {@code false}, throwing an exception when nulls are mapped to Java primitives.
*/
public void setPrimitivesDefaultedForNullValue(boolean primitivesDefaultedForNullValue) {
this.primitivesDefaultedForNullValue = primitivesDefaultedForNullValue;
}
/**
* Return whether we're defaulting Java primitives in the case of mapping a null value
* from corresponding database fields.
*/
public boolean isPrimitivesDefaultedForNullValue() {
return primitivesDefaultedForNullValue;
}
/**
* Extract the values for all columns in the current row.
*
Utilizes public setters and result set metadata.
* @see java.sql.ResultSetMetaData
*/
@Override
public T mapRow(ResultSet rs, int rowNumber) {
Assert.state(this.mappedClass != null, "Mapped class was not specified");
T mappedObject = BeanUtils.instantiate(this.mappedClass);
BeanWrapper bw = PropertyAccessorFactory.forBeanPropertyAccess(mappedObject);
initBeanWrapper(bw);
try {
ResultSetMetaData rsmd = rs.getMetaData();
int columnCount = rsmd.getColumnCount();
Set populatedProperties = (isCheckFullyPopulated() ? new HashSet() : null);
for (int index = 1; index <= columnCount; index++) {
String column = JdbcUtils.lookupColumnName(rsmd, index);
// PropertyDescriptor pd = this.mappedFields.get(column.replaceAll(" ", "").toLowerCase());
boolean nestedProperty = false;
String columnName = column.replaceAll(" ", "").toLowerCase();
if (column.contains(".")) {
nestedProperty = true;
columnName = cn.featherfly.common.lang.StringUtils.substringBefore(columnName, ".");
}
// PropertyDescriptor pd = this.mappedFields.get(column.replaceAll(" ", "").toLowerCase());
PropertyDescriptor pd = this.mappedFields.get(columnName);
if (pd != null) {
try {
Object value = null;
try {
// TODO bw.setPropertyValue支持带嵌套设值，所以只需要多加入一个判断就行了，就是前面column包含.就只判断.前面部分
if (nestedProperty) {
// 嵌套设值，所以直接使用SQL查询出来列的别名
// bw.setPropertyValue(column.replaceAll(" ", ""), value);
// cn.featherfly.common.bean.BeanUtils.setProperty(mappedObject, column.replaceAll(" ", ""), value);
BeanDescriptor bd = BeanDescriptor.getBeanDescriptor(mappedClass);
BeanProperty bp = bd.getChildBeanProperty(column.replaceAll(" ", ""));
if (bp != null) {
value = JdbcUtils.getResultSetValue(rs, index, bp.getType());
bd.setProperty(mappedObject, column.replaceAll(" ", ""), value);
}
} else {
if (logger.isDebugEnabled() && rowNumber == 0) {
logger.debug("Mapping column '" + column + "' to property '" +
pd.getName() + "' of type " + pd.getPropertyType());
}
value = getColumnValue(rs, index, pd);
bw.setPropertyValue(pd.getName(), value);
}
}
catch (TypeMismatchException e) {
if (value == null && primitivesDefaultedForNullValue) {
logger.debug("Intercepted TypeMismatchException for row " + rowNumber +
" and column '" + column + "' with value " + value +
" when setting property '" + pd.getName() + "' of type " + pd.getPropertyType() +
" on object: " + mappedObject);
}
else {
throw e;
}
}
if (populatedProperties != null) {
populatedProperties.add(pd.getName());
}
}
catch (NotWritablePropertyException ex) {
throw new DataRetrievalFailureException(
"Unable to map column " + column + " to property " + pd.getName(), ex);
}
}
}
if (populatedProperties != null && !populatedProperties.equals(this.mappedProperties)) {
throw new InvalidDataAccessApiUsageException("Given ResultSet does not contain all fields " +
"necessary to populate object of class [" + this.mappedClass + "]: " + this.mappedProperties);
}
} catch (SQLException e) {
throw new JdbcException(e);
}
return mappedObject;
}
/**
* Initialize the given BeanWrapper to be used for row mapping.
* To be called for each row.
* The default implementation is empty. Can be overridden in subclasses.
* @param bw the BeanWrapper to initialize
*/
protected void initBeanWrapper(BeanWrapper bw) {
}
/**
* Retrieve a JDBC object value for the specified column.
*
The default implementation calls
* {@link JdbcUtils#getResultSetValue(java.sql.ResultSet, int, Class)}.
* Subclasses may override this to check specific value types upfront,
* or to post-process values return from {@code getResultSetValue}.
* @param rs is the ResultSet holding the data
* @param index is the column index
* @param pd the bean property that each result object is expected to match
* (or {@code null} if none specified)
* @return the Object value
* @throws SQLException in case of extraction failure
* @see org.springframework.jdbc.support.JdbcUtils#getResultSetValue(java.sql.ResultSet, int, Class)
*/
protected Object getColumnValue(ResultSet rs, int index, PropertyDescriptor pd) throws SQLException {
return JdbcUtils.getResultSetValue(rs, index, pd.getPropertyType());
}
}