java连接oracle数据库简单实例

package cn.com.login.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class LoginDao {
public String getUserName(String userCode){
Connection con = null;
PreparedStatement pre = null;
ResultSet result = null;
String userName = "";
try {
Class.forName("oracle.jdbc.driver.OracleDriver"); //加载Oracle驱动程序
System.out.println("开始尝试连接数据库！");
String url = "jdbc:oracle:" + "thin:@10.10.19.19:1521:db123";
String user = "system";
String password = "scc123456";

con = DriverManager.getConnection(url, user, password);
System.out.println("连接成功");
String sql = "select userName from web01_test where userCode = ?";
pre = con.prepareStatement(sql);
pre.setString(1, userCode);
result = pre.executeQuery();

while (result.next()) {
userName = result.getString("userName");
}

} catch (Exception e) {
e.printStackTrace();
} finally {
try {
if (result != null) {
result.close();
}
if (pre != null) {
pre.close();
}
if (con != null) {
con.close();
}

} catch (Exception e2) {
e2.printStackTrace();
}
}

return userName;
}
}