第一个类：

package dina.web.test;

import java.sql.*;

public class DBHelper {
public static final String DRIVER = "com.mysql.jdbc.Driver";
public static final String URL = "jdbc:mysql://58.215.50.62:3307/iov";
public static final String USER = "iov_user";
public static final String PASSWORD = "2wsx3edc";

public Connection conn = null;
public PreparedStatement pst = null;

public DBHelper(String sql) {
try {
Class.forName(DRIVER);
conn = DriverManager.getConnection(URL, USER, PASSWORD);
pst = conn.prepareStatement(sql);
} catch (Exception e) {
e.printStackTrace();
}
}

public void close() {
try {
if (pst != null) {
this.pst.close();
}

} catch (Exception e) {
e.printStackTrace();
}
try {
if (conn != null) {
this.conn.close();
}
} catch (Exception e) {
e.printStackTrace();
}

}
}

第二个类：

package dina.web.test;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class SQLExcute {

static DBHelper db = null;
static String sql = null;
static ResultSet rs = null;

public static void main(String[] args) {
sql = "SELECT * from sys_user where USERNAME=‘15020151106‘";
db = new DBHelper(sql);
try {
rs=db.pst.executeQuery();
while (rs.next()) {

System.out.println("账号："+rs.getString(3));
System.out.println("姓名："+rs.getString(4));
}
rs.close();
db.close();

} catch (SQLException e) {
e.printStackTrace();
}
}

}

JAVA使用JDBC连接MySQL数据库