package com.jointsky.automonitor.alarmnotice.noticemanager.utils;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.Column;
import javax.persistence.Entity;
import org.apache.commons.beanutils.BeanUtils;
/**
* <p>
* Description:resultset结果集转换为实体List
* </p>
* <p>
* Copyright:Copyright(c) 2016
* </p>
* <p>
* </p>
*/
public class ResultSetMapper<T> {
@SuppressWarnings({ "rawtypes", "unchecked" })
public static <T>List<T> mapRersultSetToObject(ResultSet rs, Class outputClass) {
List<T> outputList = null;
try {
// make sure resultset is not null
if (rs != null) {
// check if outputClass has 'Entity' annotation
if (outputClass.isAnnotationPresent(Entity.class)) {
// get the resultset metadata
ResultSetMetaData rsmd = rs.getMetaData();
// get all the attributes of outputClass
Field[] fields = outputClass.getDeclaredFields();
while (rs.next()) {
T bean = (T) outputClass.newInstance();
for (int _iterator = 0; _iterator < rsmd
.getColumnCount(); _iterator++) {
// getting the SQL column name
String columnName = rsmd
.getColumnName(_iterator + 1);
// reading the value of the SQL column
Object columnValue = rs.getObject(_iterator + 1);
// iterating over outputClass attributes to check if any attribute has 'Column' annotation with matching 'name' value
for (Field field : fields) {
if (field.isAnnotationPresent(Column.class)) {
Column column = field
.getAnnotation(Column.class);
if (column.name().equalsIgnoreCase(
columnName)
&& columnValue != null) {
BeanUtils.setProperty(bean, field
.getName(), columnValue);
break;
}
}
}
}
if (outputList == null) {
outputList = new ArrayList<T>();
}
outputList.add(bean);
}
} else {
// throw some error
}
}
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
if (outputList == null) {
outputList = new ArrayList<T>();
}
return outputList;
}
}
//注：实体名上加上@Entity,属性上加上@Column(name="数据库字段名")
