关于数据库连接操作的工具类DBUtil.java

package Util;

import java.sql.CallableStatement;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import javax.naming.Context;

import javax.naming.InitialContext;

import javax.naming.NamingException;

import javax.sql.DataSource;

/**

* 数据库连接

* @author 吕贤丰

*

*/

public class DBUtil {

private static Connection con ;

private static PreparedStatement pstmt;

private static CallableStatement cstmt;

private static ResultSet rs;

/**

* 数据库连接

* @return Connection

*/

public static Connection getConnection(){

try {

Context context =(Context)new InitialContext();

DataSource dataSource =(DataSource)context.lookup("java:comp/env/stus");

con = dataSource.getConnection();

} catch (NamingException e) {

e.printStackTrace();

} catch (SQLException e) {

e.printStackTrace();

}

return con;

}

/**

* 数据处理(非事物)

* @param sql

* @return pstmt

*/

public static PreparedStatement getPstmt(String sql){

try {

if(con == null || con.isClosed()){

getConnection();

}

pstmt = con.prepareStatement(sql);

} catch (SQLException e) {

e.printStackTrace();

}

return pstmt;

}

/**

* 数据处理(存储过程)

* @param sql

* @return

*/

public static CallableStatement getCstmt(String sql){

try {

if(con == null || con.isClosed()){

getConnection();

}

cstmt = con.prepareCall(sql);

} catch (SQLException e) {

e.printStackTrace();

}

return cstmt;

}

/**

* 修改、删除、添加

* @return num(执行影响的行数)

*/

public static int update(){

int num = 0;

try {

num = pstmt.executeUpdate();

} catch (SQLException e) {

e.printStackTrace();

}

return num;

}

/**

* 数据查询(SQL)

* @return rs(结果集)

*/

public static ResultSet query() {

try {

rs = pstmt.executeQuery();

} catch (SQLException e) {

e.printStackTrace();

}

return rs;

}

/**

* 存储过程执行

*

*/

public static boolean execute() {

try {

cstmt.execute();

return true;

} catch (SQLException e) {

e.printStackTrace();

}

return false;

}

/**

* 数据库关闭操作

*/

public static void close(){

if(rs!=null){

try {

rs.close();

} catch (SQLException e) {

e.printStackTrace();

}

}else if(cstmt!=null){

try {

cstmt.close();

} catch (SQLException e) {

e.printStackTrace();

}

}else if(pstmt!=null){

try {

pstmt.close();

} catch (SQLException e) {

e.printStackTrace();

}

}else if(con!=null){

try {

con.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}

}