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package
my.db;
import
java.io.Serializable;
import
java.math.BigInteger;
import
java.sql.*;
import
java.util.*;
import
my.cache.CacheManager;
import
net.oschina.Configurations;
import
org.apache.commons.dbutils.QueryRunner;
import
org.apache.commons.dbutils.handlers.*;
import
org.apache.commons.lang.ArrayUtils;
/**
*
数据库查询助手
*
@author Winter Lau<br> */
@SuppressWarnings("unchecked")
public
class
QueryHelper {
private
final
static
QueryRunner _g_runner = new
QueryRunner();
private
final
static
ColumnListHandler _g_columnListHandler = new
ColumnListHandler(){
@Override
protected
Object handleRow(ResultSet rs) throws
SQLException {
Object
obj = super.handleRow(rs);
if(obj
instanceof
BigInteger)
return
((BigInteger)obj).longValue();
return
obj;
}
};
private
final
static
ScalarHandler _g_scaleHandler = new
ScalarHandler(){
@Override
public
Object handle(ResultSet rs) throws
SQLException {
Object
obj = super.handle(rs);
if(obj
instanceof
BigInteger)
return
((BigInteger)obj).longValue();
return
obj;
}
};
private
final
static
List<Class<?>> PrimitiveClasses = new
ArrayList<Class<?>>(){{
add(Long.class);
add(Integer.class);
add(String.class);
add(java.util.Date.class);
add(java.sql.Date.class);
add(java.sql.Timestamp.class);
}};
private
final
static
boolean
_IsPrimitive(Class<?> cls) {
return
cls.isPrimitive() || PrimitiveClasses.contains(cls) ;
}
/**
*
获取数据库连接
*
@return
*/
public
static
Connection getConnection() {
try{
return
Configurations.getConnection();
}catch(SQLException
e){
throw
new
DBException(e);
}
}
/**
*
读取某个对象
*
@param sql
*
@param params
*
@return
*/
@SuppressWarnings("rawtypes")
public
static
<T> T read(Class<T> beanClass, String sql, Object...params) {
try{
return
(T)_g_runner.query(getConnection(), sql, _IsPrimitive(beanClass)?_g_scaleHandler:new
BeanHandler(beanClass), params);
}catch(SQLException
e){
throw
new
DBException(e);
}
}
public
static
<T> T read_cache(Class<T> beanClass, String cache, Serializable key, String sql, Object...params) {
T
obj = (T)CacheManager.get(cache, key);
if(obj
== null){
obj
= read(beanClass, sql, params);
CacheManager.set(cache,
key, (Serializable)obj);
}
return
obj;
}
/**
*
对象查询
*
@param <T>
*
@param beanClass
*
@param sql
*
@param params
*
@return
*/
@SuppressWarnings("rawtypes")
public
static
<T> List<T> query(Class<T> beanClass, String sql, Object...params) {
try{
return
(List<T>)_g_runner.query(getConnection(), sql, _IsPrimitive(beanClass)?_g_columnListHandler:new
BeanListHandler(beanClass), params);
}catch(SQLException
e){
throw
new
DBException(e);
}
}
/**
*
支持缓存的对象查询
*
@param <T>
*
@param beanClass
*
@param cache_region
*
@param key
*
@param sql
*
@param params
*
@return
*/
public
static
<T> List<T> query_cache(Class<T> beanClass, String cache_region, Serializable key, String sql, Object...params) {
List<T>
objs = (List<T>)CacheManager.get(cache_region, key);
if(objs
== null){
objs
= query(beanClass, sql, params);
CacheManager.set(cache_region,
key, (Serializable)objs);
}
return
objs;
}
/**
*
分页查询
*
@param <T>
*
@param beanClass
*
@param sql
*
@param page
*
@param count
*
@param params
*
@return
*/
public
static
<T> List<T> query_slice(Class<T> beanClass, String sql, int
page, int
count, Object...params) {
if(page
< 0
|| count < 0)
throw
new
IllegalArgumentException("Illegal
parameter of ‘page‘ or ‘count‘, Must be positive.");
int
from = (page - 1)
* count;
count
= (count > 0)
?
count : Integer.MAX_VALUE;
return
query(beanClass, sql + "
LIMIT ?,?",
ArrayUtils.addAll(params, new
Integer[]{from,count}));
}
/**
*
支持缓存的分页查询
*
@param <T>
*
@param beanClass
*
@param cache
*
@param cache_key
*
@param cache_obj_count
*
@param sql
*
@param page
*
@param count
*
@param params
*
@return
*/
public
static
<T> List<T> query_slice_cache(Class<T> beanClass, String cache, Serializable cache_key,
int
cache_obj_count, String sql, int
page, int
count, Object...params) {
List<T>
objs = (List<T>)CacheManager.get(cache, cache_key);
if(objs
== null)
{
objs
= query_slice(beanClass, sql, 1,
cache_obj_count, params);
CacheManager.set(cache,
cache_key, (Serializable)objs);
}
if(objs
== null
|| objs.size()==0)
return
objs;
int
from = (page - 1)
* count;
if(from
< 0)
return
null;
if((from+count)
> cache_obj_count)//超出缓存的范围
return
query_slice(beanClass, sql, page, count, params);
int
end = Math.min(from + count, objs.size());
if(from
>= end)
return
null;
return
objs.subList(from, end);
}
/**
*
运行统计查询语句。语句的运行结果必须仅仅返回一个数值
*
@param sql
*
@param params
*
@return
*/
public
static
long
stat(String sql, Object...params) {
try{
Number
num = (Number)_g_runner.query(getConnection(), sql, _g_scaleHandler, params);
return
(num!=null)?num.longValue():-1;
}catch(SQLException
e){
throw
new
DBException(e);
}
}
/**
*
运行统计查询语句。语句的运行结果必须仅仅返回一个数值
*
@param cache_region
*
@param key
*
@param sql
*
@param params
*
@return
*/
public
static
long
stat_cache(String cache_region, Serializable key, String sql, Object...params) {
Number
value = (Number)CacheManager.get(cache_region, key);
if(value
== null){
value
= stat(sql, params);
CacheManager.set(cache_region,
key, value);
}
return
value.longValue();
}
/**
*
运行INSERT/UPDATE/DELETE语句
*
@param sql
*
@param params
*
@return
*/
public
static
int
update(String sql, Object...params) {
try{
return
_g_runner.update(getConnection(), sql, params);
}catch(SQLException
e){
throw
new
DBException(e);
}
}
/**
*
批量运行指定的SQL语句
*
@param sql
*
@param params
*
@return
*/
public
static
int[]
batch(String sql, Object[][] params) {
try{
return
_g_runner.batch(getConnection(), sql, params);
}catch(SQLException
e){
throw
new
DBException(e);
}
}
}
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