Java JDBC数据操作封装
Java的JDBC数据操作封装
package com.xu.dao;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class DBHelper {
//private static DataSource dataSource;
private Connection connection=null;
private PreparedStatement pstmt=null;
private ResultSet rsultset=null;
static{
try {
//Context context = new InitialContext();
//dataSource = (DataSource) context.lookup("java:comp/env/jdbc/product");
Class.forName(MyProperties.getInstance().getProperty("driverClassName"));
} catch (Exception e) {
e.printStackTrace();
}
}
public Connection getConnection(){
Connection connection = null;
try {
//connection=(Connection) DriverManager.getConnection(MyProperties.getInstance().getProperty("url"),MyProperties.getInstance().getProperty("username"),MyProperties.getInstance().getProperty("password"));
connection=(Connection) DriverManager.getConnection(MyProperties.getInstance().getProperty("url"),MyProperties.getInstance().getProperty("username"),MyProperties.getInstance().getProperty("password"));
} catch (SQLException e) {
e.printStackTrace();
}
// if (dataSource != null){
// try {
// //connection = dataSource.getConnectionection();
// connection=(Connection) DriverManager.getConnectionection(MyProperties.getInstance().getProperty("url"),MyProperties.getInstance().getProperty("username"),MyProperties.getInstance().getProperty("password"));
// } catch (SQLException e) {
// e.printStackTrace();
// }
// }
return connection;
}
//class反射
/**
* 关闭的方法
*/
public void closeAll(Connection connection,PreparedStatement pstmt,ResultSet rs){
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(pstmt!=null){
try {
pstmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if(connection!=null){
try {
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
/**
* 设置预编译数据
* @param pstmt 预编译对象
* @param params 预编译数据
*/
public void setValues(PreparedStatement pstmt,List<Object> params){
if(pstmt!=null&¶ms!=null&¶ms.size()>0){
String type=null;
for(int i=0;i<params.size();i++){
Object object=params.get(i);
try {
if(object!=null){
type=object.getClass().getName();
if("javax.sql.rowset.serial.SerialBlob".equals(type)){//javax.sql.rowset.serial.SerialBlob
pstmt.setBlob(i+1, (Blob)params.get(i));
}else if("java.lang.Integer".equals(type)){//java.lang.Integer
pstmt.setInt(i+1,Integer.parseInt(String.valueOf(object)));
}else if("java.lang.Double".equals(type)){//java.lang.Double
pstmt.setDouble(i+1, Double.parseDouble(String.valueOf(object)));
}else if("java.lang.Float".equals(type)){//java.lang.Float
pstmt.setDouble(i+1, Float.parseFloat(String.valueOf(object)));
}else if("java.lang.Long".equals(type)){//java.lang.Long
pstmt.setLong(i+1, Long.parseLong(String.valueOf(object)));
}else if("java.lang.Short".equals(type)){//java.lang.Short
pstmt.setShort(i+1, Short.parseShort(String.valueOf(object)));
}else if("java.lang.String".equals(type)){//java.lang.String
pstmt.setString(i+1,String.valueOf(object));
}else if("java.lang.Timestamp".equals(type)){//java.sql.Timestamp
pstmt.setTimestamp(i+1,(Timestamp)params.get(i));
}else{
pstmt.setString(i+1,String.valueOf(object));
}
}else{
pstmt.setString(i+1,"");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
/**
* 设置预编译数据
* @param pstmt 预编译对象
* @param objs 预编译数据
*/
public void setValues(PreparedStatement pstmt,Object ... objs){
if(pstmt!=null&&objs!=null&&objs.length>0){
String type=null;
for(int i=0,len=objs.length;i<len;i++){
Object object=objs[i];
try {
if(object!=null){
type=object.getClass().getName();
if("javax.sql.rowset.serial.SerialBlob".equals(type)){//javax.sql.rowset.serial.SerialBlob
pstmt.setBlob(i+1, (Blob)objs[i]);
}else if("java.lang.Integer".equals(type)){//java.lang.Integer
pstmt.setInt(i+1,Integer.parseInt(String.valueOf(object)));
}else if("java.lang.Double".equals(type)){//java.lang.Double
pstmt.setDouble(i+1, Double.parseDouble(String.valueOf(object)));
}else if("java.lang.Float".equals(type)){//java.lang.Float
pstmt.setDouble(i+1, Float.parseFloat(String.valueOf(object)));
}else if("java.lang.Long".equals(type)){//java.lang.Long
pstmt.setLong(i+1, Long.parseLong(String.valueOf(object)));
}else if("java.lang.Short".equals(type)){//java.lang.Short
pstmt.setShort(i+1, Short.parseShort(String.valueOf(object)));
}else if("java.lang.String".equals(type)){//java.lang.String
pstmt.setString(i+1,String.valueOf(object));
}else if("java.lang.Timestamp".equals(type)){//java.sql.Timestamp
pstmt.setTimestamp(i+1,(Timestamp)objs[i]);
}else{
pstmt.setString(i+1,String.valueOf(object));
}
}else{
pstmt.setString(i+1,"");
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
/**
* 多SQL增删改(不建议使用)
* @param sql sql语句(使用?作为占位符)
* @param params sql语句参数
* @return 结果(-1代表失败,大于0表示成功)
*/
public int update(List<String> sql,List<List<Object>> params){
connection=this.getConnection();
int result=0;
try {
connection.setAutoCommit(false); //事务处理
for(int i=0;i<sql.size();i++){
List<Object> param=params.get(i);
pstmt=connection.prepareStatement(sql.get(i)); //预编译对象
setValues(pstmt,param); //设置参数
result=pstmt.executeUpdate();
}
connection.commit(); //没有错处执行
} catch (SQLException e) {
e.printStackTrace();
try {
connection.rollback(); //出错回滚
} catch (SQLException e1) {
e1.printStackTrace();
}
}finally{
closeAll(connection,pstmt,null);
}
return result;
}
/**
* 单表增删改
* @param sql sql语句
* @param params 参数
* @return 结果(-1代表失败,大于0表示成功)
*/
public int update(String sql,List<Object> params){
connection=this.getConnection();
int result=0;
try {
pstmt=connection.prepareStatement(sql);//预编译对象
setValues(pstmt,params);//设置参数
result=pstmt.executeUpdate();
} catch (SQLException e) {
try {
connection.rollback(); //出错回滚
} catch (SQLException e1) {
e1.printStackTrace();
}
}finally{
closeAll(connection,pstmt,null);
}
return result;
}
/**
* 单表增删改
* @param sql sql语句
* @param params 参数
* @return 结果(-1代表失败,大于0表示成功)
*/
public int update(String sql,Object ... params){
connection=this.getConnection();
int result=0;
try {
pstmt=connection.prepareStatement(sql); //预编译对象
setValues(pstmt,params); //设置参数
result=pstmt.executeUpdate();
} catch (SQLException e) {
try {
connection.rollback(); //出错回滚
} catch (SQLException e1) {
e1.printStackTrace();
}
}finally{
closeAll(connection,pstmt,null);
}
return result;
}
/**
* 多SQL查询(不建议使用)
* @param sql sql语句(使用?作为占位符)
* @param params sql语句参数
* @return 结果
*/
public List<String> find(String sql,List<Object> params){
List<String> list=new ArrayList<String>();
connection=this.getConnection();
try {
pstmt=connection.prepareStatement(sql); //预编译对象
setValues(pstmt,params); //设置参数
rsultset=pstmt.executeQuery(); //执行查询
ResultSetMetaData md=rsultset.getMetaData(); //结果集的元数据，它反映了结果集的信息
int count=md.getColumnCount(); //取出结果集中列的数量
if(rsultset.next()){
for(int i=1;i<=count;i++){
list.add(rsultset.getString(i));
}
}
} catch (SQLException e) {
//TODO:
}finally{
closeAll(connection,pstmt,rsultset);
}
return list;
}
/**
* 单表查询
* @param sql sql语句(使用?作为占位符)
* @param params sql语句参数
* @return 结果
*/
public List<String> find(String sql,Object ... params){
List<String> list=new ArrayList<String>();
connection=this.getConnection();
try {
pstmt=connection.prepareStatement(sql); //预编译对象
setValues(pstmt,params); //设置参数
rsultset=pstmt.executeQuery(); //执行查询
ResultSetMetaData md=rsultset.getMetaData(); //结果集的元数据，它反映了结果集的信息
int count=md.getColumnCount(); //取出结果集中列的数量
if(rsultset.next()){
for(int i=1;i<=count;i++){
list.add(rsultset.getString(i));
}
}
} catch (SQLException e) {
e.printStackTrace();
}finally{
closeAll(connection,pstmt,rsultset);
}
return list;
}
/**
* 单表查询
* @param sql sql语句
* @param c JavaBean
* @param params sql语句参数
* @return 结果
* @throws NumberFormatException
* @throws InstantiationException
* @throws IllegalAccessException
* @throws IllegalArgumentException
* @throws InvocationTargetException
*/
public <T> List<T> find(String sql,Class<T> c ,List<Object> params) throws NumberFormatException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
if( params==null){
return find(sql,c);
}else{
return find(sql,c,params.toArray());
}
}
private Set<String> getMethodName(Set<String> keys){
Set<String> result=new HashSet<String>();
for(String key:keys){
String newName="set"+key.substring(0,1).toUpperCase()+key.substring(1);
result.add(newName);
}
return result;
}
/**
* 单表查询
* @param sql sql语句
* @param c JavaBean
* @param params sql语句参数
* @return 结果
* @throws NumberFormatException
* @throws InstantiationException
* @throws IllegalAccessException
* @throws IllegalArgumentException
* @throws InvocationTargetException
*/
public <T> List<T> find(String sql,Class<T> c,Object ... params) throws InstantiationException, IllegalAccessException, NumberFormatException, IllegalArgumentException, InvocationTargetException{
List<Map<String, Object>> listMap=finds(sql,params);
List <T> list=new ArrayList<T>(); //要返回的结果的集合
T t=null;
connection=this.getConnection();
if( listMap==null|| listMap.size()<=0){
return list;
}
Map<String,Object> map=listMap.get(0);
Set<String> keys=map.keySet();
Set<String> methodNames=getMethodName(keys);//拼接方法
Method[] ms=c.getMethods();
for( Map<String,Object> m:listMap){
t=(T)c.newInstance();
for( Method method:ms){//这个是获取的方法
for(String mn:methodNames){//这个是拼接的方法
if( method.getName().equals(mn)){
String keyname=mn.substring(3,4).toLowerCase()+mn.substring(4);
String typeName=method.getParameterTypes()[0].getName();
if( "java.lang.Integer".equals(typeName)|| "int".equals(typeName)){
method.invoke(t,Integer.parseInt(m.get(keyname).toString()));
}else if( "java.lang.Double".equals(typeName)|| "double".equals(typeName)){
method.invoke(t,Double.parseDouble(m.get(keyname).toString()));
}else if( "java.lang.Float".equals(typeName)|| "float".equals(typeName)){
method.invoke(t,Float.parseFloat(m.get(keyname).toString()));
}else if( "java.lang.Long".equals(typeName)|| "long".equals(typeName)){
method.invoke(t,Long.parseLong(m.get(keyname).toString()));
}else {
method.invoke(t,m.get(keyname).toString());
}
break;
}
}
}
list.add(t);
}
return list;
}
/**
* 单表查询
* @param sql sql语句
* @param params sql语句参数
* @return 结果
*/
public List<Map<String,Object>> finds(String sql,List<Object> params){
if(params==null){
return finds(sql);
}else{
return finds(sql, params.toArray());
}
}
/**
* 单表查询
* @param sql sql语句
* @param params sql语句参数
* @return 结果
*/
public List<Map<String,Object>> finds(String sql,Object ... objs){
List<Map<String,Object>> list=new ArrayList<Map<String,Object>>();
connection=this.getConnection();
try {
pstmt=connection.prepareStatement(sql);
this.setValues(pstmt,objs);//给占位符赋值
rsultset=pstmt.executeQuery();//获取结果集
//获取返回结果中的列的列名
ResultSetMetaData rsmd=rsultset.getMetaData();
int colLen=rsmd.getColumnCount(); //获取结果集中列的数量
String[] colNames=new String[colLen];
for(int i=0;i<colLen;i++){//取出每个列的列名存放到数组中
colNames[i]=rsmd.getColumnName(i+1);
}
Map<String,Object> map=null;
String typeName;
Object obj;
while(rsultset.next()){//循环取值，每循环一次就是一条记录，存放到一个map中
map=new HashMap<String,Object>();
for(int i=0;i<colLen;i++){ //循环取出每个列的值
obj=rsultset.getObject(colNames[i]);
if(obj!=null){
typeName=obj.getClass().getSimpleName();
if("BLOB".equals(typeName)){
Blob blob=rsultset.getBlob(colNames[i]);
byte[] bt=null;
BufferedInputStream bis=null;
try {
bis=new BufferedInputStream( blob.getBinaryStream());
bt=new byte[(int) blob.length()];
bis.read(bt);
map.put(colNames[i],bt);
} catch (IOException e) {
e.printStackTrace();
} finally{
if(bis!=null){
try {
bis.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
}else{
map.put(colNames[i],rsultset.getString(colNames[i]));
}
}else{
map.put(colNames[i],""); //以当前列的列名为键，以当前列的值为值
}
}
list.add(map);
}
} catch (SQLException e) {
e.printStackTrace();
} finally{
this.closeAll(connection, pstmt, rsultset);
}
return list;
}
}
使用方法
public class Test{
public static void main(String[] args){
DBHelper helper=new DBHeloer();
//这里是用？来作为SQL的占位符
String sql="select * from student where id=? and name=?";
List