package cn.molesoft.yanShulcsy.utils;
import java.io.IOException;
import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
/**
* JDBC连接数据库的工具类
* @author Administrator
*
*/
public class JdbcUtil {
//第一步:声明所有需要的静态的全局变量
private static final long serialVersionUID =1L;
private static final String JDBC_DRIVER;
private static final String DB_URL;
private static final String USER;
private static final String PASS;
private static final Properties pros;
//第2不加载读取配置文件，并初始化静态变量
static
{
//读取和处理资源文件的信息
pros=new Properties();
try {
pros.load(Thread.currentThread().getContextClassLoader().getResourceAsStream("db.properties"));
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
JDBC_DRIVER=pros.getProperty("jdbc.driver");
DB_URL=pros.getProperty("jdbc.url");
USER = pros.getProperty("jdbc.username");
PASS = pros.getProperty("jdbc.password");
}
//第二步要加载数据驱动
static{
try {
Class.forName(JDBC_DRIVER);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//第3步获得数据库连接
public static Connection getConn()
{
try {
return DriverManager.getConnection(DB_URL,USER,PASS);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
//第4步释放资源
public static void closeConn(ResultSet rs, CallableStatement cs, PreparedStatement ps, Connection conn)
{
try {
if(rs!=null)
{
rs.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
if(null != cs)
{
cs.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
if(ps != null)
{
ps.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
if(conn != null)
{
conn.close();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/* 查询数据库，输出符合要求的记录的情况*/
public static void query() throws SQLException
{//查询方法的思路:加载驱动，连接数据库，创建sql语句执行对象 ，执行sql语句，对执行结果进行处理，关闭相关的连接对象（顺序跟声明的顺序相反）
String sql="select * from usersso";
// 首先要获取连接，即连接到数据库
getConn();
//创建sql语句执行对象 ，
Statement st = getConn().createStatement();//创建sql执行对象
// 执行sql语句，
ResultSet rs=st.executeQuery(sql);
//5.处理结果集
while(rs.next()){
int id = rs.getInt("id");
String name = rs.getString("name");
System.out.println(rs.getInt("id")+" "
+rs.getString("name"));
}
}
/**
* 测试jdbc连接数据库是否成功
* @param args
* @throws ClassNotFoundException
* @throws SQLException
*/
public static void main(String[] args) throws ClassNotFoundException, SQLException {
query();
}
}
