一个SpringJDBC的泛型DAO和通用业务层组件
1说明一下
最近要做一个系统，这个系统是基于Spring的。这篇博客减少了一些无关的代码。这个比较简单容易看懂。另外一些一对多多对多等等没有贴出来，但大体是一样的，基于反射机制去实现，并且自定义一些注解来设置实体间关系等等。。。。
实体类：
为了方便，这里自定义一个规范，就是主键一定要命名为id，field名称一定要与表的字段名一致。
package com.lin.jllm.domain;
import java.text.SimpleDateFormat;
import java.util.Date;
/**
*
* create table ORDER_INFO(
id int not null primary key auto_increment, #订单号
startTime date not null, #发货时间
stateTime date, #状态时间
positionInfo varchar(255) not null default '未发货', #位置信息
sourceInfo varchar(255) not null, #来源信息
destinationInfo varchar(255) not null); #目的地信息
*
* @author lin
*
*/
public class OrderInfo {
private Integer id;
private Date startTime;
private Date stateTime;
private String positionInfo;
private String sourceInfo;
private String destinationInfo;
public OrderInfo() {
super();
// TODO Auto-generated constructor stub
}
public OrderInfo(Integer id, Date startTime, Date stateTime,
String positionInfo, String sourceInfo, String destinationInfo) {
super();
this.id = id;
this.startTime = startTime;
this.stateTime = stateTime;
this.positionInfo = positionInfo;
this.sourceInfo = sourceInfo;
this.destinationInfo = destinationInfo;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public Date getStartTime() {
return startTime;
}
public void setStartTime(Date startTime) {
this.startTime = startTime;
}
public Date getStateTime() {
return stateTime;
}
public void setStateTime(Date stateTime) {
this.stateTime = stateTime;
}
public String getPositionInfo() {
return positionInfo;
}
public void setPositionInfo(String positionInfo) {
this.positionInfo = positionInfo;
}
public String getSourceInfo() {
return sourceInfo;
}
public void setSourceInfo(String sourceInfo) {
this.sourceInfo = sourceInfo;
}
public String getDestinationInfo() {
return destinationInfo;
}
public void setDestinationInfo(String destinationInfo) {
this.destinationInfo = destinationInfo;
}
@Override
public String toString() {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:SS");
return "OrderInfo [id=" + id + ", startTime=" + sdf.format(getStartTime()).toString()
+ ", stateTime=" + sdf.format(getStateTime()).toString() + ", positionInfo=" + positionInfo
+ ", sourceInfo=" + sourceInfo + ", destinationInfo="
+ destinationInfo + "]";
}
}
2 DAO接口
2.1泛型DAO接口
package com.lin.jllm.dao.intf;
import java.util.List;
import com.lin.jllm.exception.DaoException;
public interface IBaseDao<T> {
public void create(T t) throws DaoException;
public T read(Integer id) throws DaoException;
public void update(T t) throws DaoException;
public void delete(Integer id) throws DaoException;
public List<T> listAll() throws DaoException;
}
2.2 DAO组件接口
package com.lin.jllm.dao.intf;
import com.lin.jllm.domain.OrderInfo;
public interface IOrderInfoDao extends IBaseDao<OrderInfo> {
}
3 DAO实现类
3.1 泛型DAO实现类
package com.lin.jllm.dao.impl;
import java.lang.reflect.Field;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import com.lin.jllm.dao.intf.IBaseDao;
import com.lin.jllm.exception.DaoException;
public abstract class AbstractDaoImpl<T> implements IBaseDao<T> {
protected JdbcTemplate jdbcTemplate;
protected String table_name;
protected Class<? extends T> type;
public AbstractDaoImpl() {
// 获取真实泛型数据类型
Type t = getClass().getGenericSuperclass();
ParameterizedType pt = (ParameterizedType) t;
type = (Class) pt.getActualTypeArguments()[0];
}
public JdbcTemplate getJdbcTemplate() {
return jdbcTemplate;
}
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
public String getTable_name() {
return table_name;
}
public void setTable_name(String table_name) {
this.table_name = table_name;
}
/**
* 注入数据源
* @param dataSource
*/
public void setDataSource(DataSource dataSource)
{
this.jdbcTemplate = new JdbcTemplate(dataSource);
}
@Override
public void create(T t) throws DaoException {
if (t != null) {
try {
Field[] fields = t.getClass().getDeclaredFields();
String nameString = "";
String valueString = "";
String sql = "insert into "+table_name;
Object[] values = new Object[fields.length];
//设置SQL中的参数名和参数个数
for(int i=0;i<fields.length;i++)
{
fields[i].setAccessible(true);//设置private属性可访问
nameString += fields[i].getName() + ",";
valueString += "?,";
values[i] = fields[i].get(t);
}
//组织SQL语句
nameString = "(" + nameString.substring(0, nameString.length() - 1) + ")values";
valueString = "(" + valueString.substring(0, valueString.length() - 1) + ")";
sql = sql + nameString + valueString;
jdbcTemplate.update(sql,values);
} catch (Exception e) {
e.printStackTrace();
}
}
}
@Override
public T read(Integer id) throws DaoException {
final Class tempType = type;
T t = jdbcTemplate.queryForObject(
"select * from "+table_name+" where id=?;", new Object[] { id },
new RowMapper<T>() {
public T mapRow(java.sql.ResultSet rs, int arg1)
throws SQLException {
try {
Object temp = tempType.newInstance();//实例化一个类用于获取field的值
Field[] fields = tempType.getDeclaredFields();
for(int i=0;i<fields.length;i++)
{
fields[i].setAccessible(true);//设置field可访问
fields[i].set(temp, rs.getObject(fields[i].getName()));//设置field的值
}
return (T) temp;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
});
return t;
}
@Override
public void update(T t) throws DaoException {
if(t != null)
{
try {
String sql = "update "+table_name+" set ";
Field[] fields = t.getClass().getDeclaredFields();
Object[] values = new Object[fields.length];
int index = 0;
//构造SQL语句
for(Field field : fields)
{
field.setAccessible(true);
//判断是不是主键
if(field.getName().equals("id"))
{
values[values.length - 1] = field.get(t);
}
else {
sql += field.getName()+"=?,";
values[index] = field.get(t);
index++;
}
}
sql = sql.substring(0, sql.length() - 1) + " where id=?";//为了去掉逗号
jdbcTemplate.update(sql, values);
} catch (Exception e) {
e.printStackTrace();
}
}
}
@Override
public void delete(Integer id) throws DaoException {
jdbcTemplate.update("delete from "+table_name+" where id=?", new Object[]{id});
}
@Override
public List<T> listAll() throws DaoException {
final Class tempType = type;
return jdbcTemplate.query("select id,startTime,stateTime,positionInfo,sourceInfo,destinationInfo from "+table_name+";",
new RowMapper<T>() {
@Override
public T mapRow(ResultSet rs, int arg1) throws SQLException {
try {
Object temp = tempType.newInstance();//实例化一个类用于获取field的值
Field[] fields = tempType.getDeclaredFields();
for(int i=0;i<fields.length;i++)
{
fields[i].setAccessible(true);//设置field可访问
fields[i].set(temp, rs.getObject(fields[i].getName()));//设置field的值
}
return (T) temp;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
});
}
}
3.2 DAO组件
package com.lin.jllm.dao.impl;
import com.lin.jllm.dao.intf.IOrderInfoDao;
import com.lin.jllm.domain.OrderInfo;
public class OrderInfoDaoImpl extends AbstractDaoImpl<OrderInfo> implements IOrderInfoDao {
}
4 业务层
4.1 泛型业务接口
package com.lin.jllm.service.intf;
import java.util.List;
public interface IBaseService<T> {
public void add(T t) throws Exception;
public void delete(Integer id) throws Exception;
public void update(T t) throws Exception;
public T get(Integer id) throws Exception;
public List<T> getAll() throws Exception;
}
4.2 业务接口
package com.lin.jllm.service.intf;
import com.lin.jllm.domain.OrderInfo;
public interface IOrderInfoService extends IBaseService<OrderInfo> {
}
4.3 泛型业务组件
package com.lin.jllm.service.impl;
import java.util.List;
import com.lin.jllm.dao.intf.IBaseDao;
import com.lin.jllm.service.intf.IBaseService;
public class AbstractServiceImpl<T> implements IBaseService<T> {
private IBaseDao<T> baseDao;
public AbstractServiceImpl() {
}
//注入DAO
public AbstractServiceImpl(IBaseDao<T> baseDao) {
this.baseDao = baseDao;
}
public IBaseDao<T> getBaseDao() {
return baseDao;
}
public void setBaseDao(IBaseDao<T> baseDao) {
this.baseDao = baseDao;
}
@Override
public void add(T t) throws Exception {
if(t != null)
{
baseDao.create(t);
}
}
@Override
public void delete(Integer id) throws Exception {
if(id != null)
{
baseDao.delete(id);
}
}
@Override
public void update(T t) throws Exception {
if(t != null)
{
baseDao.update(t);
}
}
@Override
public T get(Integer id) throws Exception {
if(id != null)
{
return baseDao.read(id);
}
return null;
}
@Override
public List<T> getAll() throws Exception {
return baseDao.listAll();
}
}
4.4 业务组件
package com.lin.jllm.service.impl;
import com.lin.jllm.dao.intf.IBaseDao;
import com.lin.jllm.dao.intf.IOrderInfoDao;
import com.lin.jllm.domain.OrderInfo;
import com.lin.jllm.service.intf.IOrderInfoService;
public class OrderInfoServiceImpl extends AbstractServiceImpl<OrderInfo> implements IOrderInfoService {
private IOrderInfoDao orderInfoDao;
public OrderInfoServiceImpl() {
}
public OrderInfoServiceImpl(IBaseDao<OrderInfo> baseDao) {
super(baseDao);
this.orderInfoDao = (IOrderInfoDao)baseDao;
}
public IOrderInfoDao getOrderInfoDao() {
return orderInfoDao;
}
public void setOrderInfoDao(IOrderInfoDao orderInfoDao) {
this.orderInfoDao = orderInfoDao;
}
}
5 在Spring容器中配置依赖关系
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:jaxws="http://cxf.apache.org/jaxws" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://cxf.apache.org/jaxws http://cxf.apache.org/schemas/jaxws.xsd"> <!-- JDBC数据源 --> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="com.mysql.jdbc.Driver" /> <property name="url" value="jdbc:mysql://localhost:3306/jeanselam" /><!-- 这个系统不使用新的数据库,使用jeanseLam的数据库 --> <property name="username" value="root" /> <property name="password" value="root" /> </bean> <!-- 通用泛型DAO组件 --> <bean name="abstractDaoImpl" class="com.lin.jllm.dao.impl.AbstractDaoImpl" abstract="true"> <property name="dataSource" ref="dataSource"></property> </bean> <!-- OrderInfo --> <bean name="orderInfoDaoImpl" class="com.lin.jllm.dao.impl.OrderInfoDaoImpl" parent="abstractDaoImpl"> <!-- 与该DAO组件对应的表名 --> <property name="table_name" value="OrderInfo"></property> </bean> </beans>
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:jaxws="http://cxf.apache.org/jaxws" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd http://cxf.apache.org/jaxws http://cxf.apache.org/schemas/jaxws.xsd"> <!-- 抽象父业务组件 --> <bean name="abstractServiceImpl" class="com.lin.jllm.service.impl.AbstractServiceImpl" abstract="true"> </bean> <!-- 订单信息管理业务组件 --> <bean name="orderInfoServiceImpl" class="com.lin.jllm.service.impl.OrderInfoServiceImpl" parent="abstractServiceImpl"> <constructor-arg ref="orderInfoDaoImpl"></constructor-arg> </bean> </beans>