新建BaseDao

package cn.wingfly.dao;

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

public class BaseDao {
Connection con = null;
Statement st = null;
ResultSet rs = null;

/**
* 获得联接
*
* @return
*/
public Connection getConnection() {
try {
// 加载驱动,这一句也可写为:Class.forName("com.mysql.jdbc.Driver");
Class.forName("com.mysql.jdbc.Driver").newInstance();

// 建立到MySQL的连接
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/money_note?characterEncoding=UTF-8", "root", "root");
} catch (Exception e) {
e.printStackTrace();
}
return con;
}

/**
* 关闭数据源
*/
public void CloseConnection(Connection con, Statement s, ResultSet rs) {
try {
if (rs != null) {
rs.close();
}
if (s != null) {
s.close();
}
if (con != null) {
con.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}


测试类

package cn.wingfly.dao;

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


public class Test extends BaseDao {

Connection con = null;
Statement st = null;
ResultSet rs = null;

/**
* 查询数据
*/
public void find() {
con = getConnection(); // 获得联接
try {
st = con.createStatement();
rs = st.executeQuery("select * from app_user");
while (rs.next()) {
System.out.println("编号:" + rs.getInt("uuid") + ", 姓名:" + rs.getString("userName") + ", 性别:" + rs.getString("sex") + ", 生日:" + rs.getString("birthday") + ", 住址:" + rs.getString("address"));
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
CloseConnection(con, st, rs); // 关闭联接
}
}

/**
* 添加数据
*/
public void add() {
con = getConnection();
try {
st = con.createStatement();
int result = st.executeUpdate("insert into app_user(userName,passWord,sex,birthday,address) values('赵丽颖','wanying','女','1992-02-03','北京市')");
if (result > 0) {
System.out.println("插入成功");
} else {
System.out.println("插入失败");
}
} catch (SQLException e) {
System.out.println("插入失败");
e.printStackTrace();
} finally {
CloseConnection(con, st, rs);
}
}

/**
* 更新数据
*/
public void update() {
con = getConnection();
try {
st = con.createStatement();
int result = st.executeUpdate("update app_user set address = '河南' where uuid = '3'");
if (result > 0) {
System.out.println("更新成功");
} else {
System.out.println("更新失败");
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
CloseConnection(con, st, rs);
}
}

/**
* 删除数据
*/
public void delete() {
con = getConnection();
try {
st = con.createStatement();
int result = st.executeUpdate("delete from app_user where uuid = '3'");
if (result > 0) {
System.out.println("删除成功");
} else {
System.out.println("删除失败");
}
} catch (SQLException e) {
e.printStackTrace();
} finally {
CloseConnection(con, st, rs);
}
}

public static void main(String[] args) {
Test test = new Test();
//test.add();
// test.update();
test.delete();
test.find();

}

}