JDBC连接数据库（Mysql、抽取工具类）

package com.jdbc.hello;

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

import org.junit.Test;

import com.jdbc.utils.JdbcUtils;

public class hello {
// 插入一条数据
@Test
public void test2() {

Connection conn = null;
PreparedStatement st = null;
ResultSet rs = null;

try {
// 获取连接
conn = JdbcUtils.getConnection();

// 编写sql
String sql = "insert into category values(?,?)";

// 获取语句执行者
st = conn.prepareStatement(sql);

// 设置参数
st.setString(1, "c005");
st.setString(2, "电脑");

// 执行sql
int i = st.executeUpdate();

// 处理结果
if (i == 1)
System.out.println("success");
else
System.out.println("fail");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
JdbcUtils.closeResource(conn, st, rs);
}
}
}

package com.jdbc.utils;

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

public class JdbcUtils {
/**
* 获取连接
* @return
* @throws ClassNotFoundException
* @throws SQLException
*/
public static Connection getConnection() throws ClassNotFoundException, SQLException{

//注册驱动
Class.forName("com.mysql.jdbc.Driver");

//获取连接
Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test?characterEncoding=utf8&useSSL=true", "root", "152500");
return conn;
}

/**
* 释放连接
* @param conn
*/
public static void closeCon(Connection conn){
if(conn!=null){
try {
conn.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

conn = null;
}
}

/**
* 释放语句执行
* @param st
*/
public static void closeStatment(PreparedStatement st){
if(st!=null){
try {
st.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

st = null;
}
}

/**
* 释放结果集
* @param rs
*/
public static void closeResultSet(ResultSet rs){
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

rs = null;
}
}

/**
* 释放资源
* @param conn
* @param st
* @param rs
*/
public static void closeResource(Connection conn, PreparedStatement st, ResultSet rs){
closeResultSet(rs);
closeStatment(st);
closeCon(conn);
}
}