• Spring的jdbcTemplate 与原始jdbc 整合c3p0的DBUtils 及Hibernate 对比 Spring配置文件生成约束的菜单方法


    以User为操作对象

    package com.swift.jdbc;
    
    public class User {
    
        private Long user_id;    
        private String    user_code;    
        private String    user_name;    
        private String    user_password;    
        private String    user_state;
        
        public User() {
            super();
            // TODO Auto-generated constructor stub
        }
        public User(Long user_id, String user_code, String user_name, String user_password, String user_state) {
            super();
            this.user_id = user_id;
            this.user_code = user_code;
            this.user_name = user_name;
            this.user_password = user_password;
            this.user_state = user_state;
        }
        public Long getUser_id() {
            return user_id;
        }
        public void setUser_id(Long user_id) {
            this.user_id = user_id;
        }
        public String getUser_code() {
            return user_code;
        }
        public void setUser_code(String user_code) {
            this.user_code = user_code;
        }
        public String getUser_name() {
            return user_name;
        }
        public void setUser_name(String user_name) {
            this.user_name = user_name;
        }
        public String getUser_password() {
            return user_password;
        }
        public void setUser_password(String user_password) {
            this.user_password = user_password;
        }
        public String getUser_state() {
            return user_state;
        }
        public void setUser_state(String user_state) {
            this.user_state = user_state;
        }
        @Override
        public String toString() {
            return "User [user_id=" + user_id + ", user_code=" + user_code + ", user_name=" + user_name + ", user_password="
                    + user_password + ", user_state=" + user_state + "]";
        }
        
    }

    原始JDBC

    这个注意ResultSet 是一个带指针的结果集,指针开始指向第一个元素的前一个(首元素),不同于iterator 有hasNext() 和next() ,他只有next()

    package com.swift.jdbc;
    
    import java.beans.PropertyVetoException;
    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.ArrayList;
    import java.util.List;
    
    import com.mchange.v2.c3p0.ComboPooledDataSource;
    
    public class DemoJDBC {
    
        public static void main(String[] args) throws ClassNotFoundException, SQLException, PropertyVetoException {
    
            findAll();
            User user=findById(9l);
            System.out.println(user);
            user.setUser_name("HanMeimei");
            update(user);
        }
    
        private static void update(User user) throws PropertyVetoException, SQLException {
    
            ComboPooledDataSource dataSource=new ComboPooledDataSource();
            dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/crm");
            dataSource.setDriverClass("com.mysql.jdbc.Driver");
            dataSource.setPassword("root");
            dataSource.setUser("root");
            dataSource.setMinPoolSize(5);
            dataSource.setMaxIdleTime(2000);
            Connection con= dataSource.getConnection();
            String sql="update sys_user set user_name='"+user.getUser_name()+"' where user_id="+user.getUser_id();
            PreparedStatement statement = con.prepareStatement(sql);
            statement.executeUpdate();
            System.out.println("ok");
            
        }
    
        private static User findById(long id) throws ClassNotFoundException, SQLException {
    
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/crm","root","root");
            Statement statement = con.createStatement();
            ResultSet rs = statement.executeQuery("select * from sys_user where user_id="+id);
            User user=null;
            while(rs.next()) {
                user=new User(rs.getLong("user_id"),rs.getString("user_code"),
                        rs.getString("user_name"),rs.getString("user_password"),
                        rs.getString("user_state"));
            }
            return user;
            
        }
    
        private static void findAll() throws ClassNotFoundException, SQLException {
    
            Class.forName("com.mysql.jdbc.Driver");
            Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/crm?user=root&password=root");
            PreparedStatement statement = connection.prepareStatement("select * from sys_user");
            ResultSet rs = statement.executeQuery();
            List<User> list=new ArrayList<>();
            while(rs.next()) {
                Long id = rs.getLong("user_id");
                String code=rs.getString("user_code");
                String name=rs.getString("user_name");
                String password=rs.getString("user_password");
                String state=rs.getString("user_state");
                User user=new User();
                user.setUser_code(code);
                user.setUser_id(id);
                user.setUser_password(password);
                user.setUser_name(name);
                user.setUser_state(state);
                list.add(user);
            }
            for(User u:list) {
                System.out.println(u);
            }
            rs.close();
            connection.close();
        }
    
        
    }

    整合c3p0的DBUtils

    c3p0整合了连接数据库的Connection ,提供更快速的连接

    package com.swift.c3p0;
    
    import java.sql.Connection;
    import java.sql.SQLException;
    
    import javax.sql.DataSource;
    
    import com.mchange.v2.c3p0.ComboPooledDataSource;
    
    public class C3P0Utils {
    
        private static ComboPooledDataSource dataSource = new ComboPooledDataSource();
        private static ThreadLocal<Connection> thread=new ThreadLocal<>();
    //    static {
    //        try {
    //            dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/crm");
    //            dataSource.setDriverClass("com.mysql.jdbc.Driver");
    //            dataSource.setUser("root");
    //            dataSource.setPassword("root");
    //            dataSource.setMinPoolSize(5);
    //        } catch (PropertyVetoException e) {
    //            e.printStackTrace();
    //        }
    //    }
        
        public static DataSource getDataSource() {
            return dataSource;
        }
        
        public static Connection getConnection() {
            Connection con = thread.get();
            if(con==null) {
                try {
                    con = dataSource.getConnection();
                    thread.set(con);
                    con=thread.get();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            return con;
            
        }
        public static void main(String[] args) {
            Connection con = C3P0Utils.getConnection();
            System.out.println(con);
        }
    }

    并可以直接加载xml配置文件,强于(DBCP连接池,他只支持properties文件)

    <c3p0-config>
        <default-config>
            <property name="jdbcUrl">jdbc:mysql://localhost:3306/crm</property>
            <property name="driverClass">com.mysql.jdbc.Driver</property>
            <property name="user">root</property>
            <property name="password">root</property>
        </default-config>
    </c3p0-config>

    DBUtils的杀手锏QueryRunner 

    可以使用?了,放置恶意注意,也提供自动增加' '符号,这个要注意

    package com.swift.dbutils;
    
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.List;
    
    import org.apache.commons.dbutils.QueryRunner;
    import org.apache.commons.dbutils.handlers.BeanHandler;
    import org.apache.commons.dbutils.handlers.BeanListHandler;
    
    import com.swift.c3p0.C3P0Utils;
    import com.swift.jdbc.User;
    
    public class DemoQueryRunner {
    
        private static QueryRunner qr=new QueryRunner(C3P0Utils.getDataSource());
        static List<User> users=new ArrayList<User>();
        
        public static void main(String[] args) throws SQLException {
            //查找所有
            users=findAll();
            for(User user:users) {
                
                System.out.println(user);
            }
            //通过Id查找
            User user=findById(9l);
            System.out.println(user);
            //更新
            user.setUser_name("韩梅梅");
            System.out.println("===================================");
            System.out.println(user);
            update(user);
            
        }
    
        private static void update(User user) throws SQLException {
    
            int update = qr.update(
                    "update sys_user set user_name=? where user_id=?",user.getUser_name(),user.getUser_id());
            System.out.println(user.getUser_name()+update);
            
        }
    
        private static List<User> findAll() throws SQLException {
            List<User> users = qr.query("select * from sys_user ", new BeanListHandler<User>(User.class));
            return users;
        }
    
        private static User findById(long l) throws SQLException {
    
            User user = qr.query(
                    "select * from sys_user where user_id=?",new BeanHandler<User>(User.class),l);
            return user;
            
        }
    
    }

    Hibernate 有个核心配置文件

    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
        <!-- 约束在hibernate-core-5.0.7.Final.jar的org.hibernate包下的hibernate-configuration-3.0.dtd文件中找 -->
    <hibernate-configuration>
        <session-factory>
        <!-- 配置方法:资料hibernate-release-5.0.7.Finalprojectetchibernate.properties -->
            <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
            <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/crm</property>
            <property name="hibernate.connection.username">root</property>
            <property name="hibernate.connection.password">root</property>
            
            <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
            
            <property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>
            <property name="hibernate.c3p0.max_size">10</property>
            <property name="hibernate.c3p0.min_size">5</property>
            <property name="hibernate.c3p0.timeout">5000</property>
            
            <property name="hibernate.hbm2ddl.auto">update</property>
            <property name="hibernate.show_sql">true</property>
            <property name="hibernate.format_sql">true</property>
              
            <property name="hibernate.connection.isolation">2</property>
            
            <!-- 获得当前session放在当前线程中 -->
            <!-- <property name="hibernate.current_session_context_class">thread</property> -->
            
            <mapping resource="com/swift/hibernate/User.hbm.xml"/>
        </session-factory>
    </hibernate-configuration>
    <property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>
    这个是使用Hibernate自带的c3p0功能,不需要自己写c3p0.xml文件,但除了需要c3p0的jar包,还需要Hibernate自带的jar包,可以在hibernate包的lib->optional->c3p0中找到,
    此文件夹中这两个jar:c3p0-0.9.1.jar和hibernate-c3p0-4.2.1.Final.jar都要用,否则异常
    Could not instantiate connection provider [org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider]

    还有个实体类的映射文件

    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-mapping PUBLIC 
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
    <!-- 约束在hibernate-core-5.0.7.Final.jar的org.hibernate包下的hibernate-mapping-3.0.dtd文件中找 -->
    <hibernate-mapping>
        <class name="com.swift.hibernate.User" table="sys_user">
            <id name="user_id" column="user_id">
                <generator class="native"></generator>
            </id>
            <property name="user_code" column="user_code"></property>
            <property name="user_name" column="user_name"></property>
            <property name="user_password" column="user_password"></property>
            <property name="user_state" column="user_state"></property>
        </class>
    </hibernate-mapping>

    连接数据库是通过session

    package com.swift.hibernate;
    
    import java.util.ArrayList;
    import java.util.List;
    
    import org.hibernate.Query;
    import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    import org.hibernate.cfg.Configuration;
    
    public class DemoHibernate {
    
        static List<User> users=new ArrayList<User>();
        public static void main(String[] args) {
    
            users=findAll();
            for(User user:users) {
                
                System.out.println(user);
            }
        }
        private static List<User> findAll() {
            
            //new Configuration()是创建Configuration类对象,调用里面的configure方法,读取配置信息,方法返回的又是Configuration类型
            Configuration config=new Configuration().configure();
            SessionFactory sf = config.buildSessionFactory();
            Session session = sf.openSession();
            Query query = session.createQuery("from User");
            users= query.list();
            session.close();
            return users;
        }
    
    }



    使用Spring的jdbcTemplate

    关于倒包

    Spring 总共有20个包看需要导入,其他还有spring的官方扩展包 (整合的较常用的一些,可根据功能导入)

    这里只要实现数据库,所以,倒spring的4个核心包beans context core expression 2个日志log4j commons-loging(可不倒)

    c3p0要倒 连接数据库mysql-connector-java  还有Spring的spring-jdbc 事务spring-tx 用注解要spring-aop

    配置文件菜单法生成

    applicationContext.xml(非官方约定俗成的,其实叫什么都可以)

    约束如果不想拷贝,可以用菜单导入 window --> preferences -->搜索(xml catalog) -->add-->file system(注意:把location最后的约束文件名复制到key的最后)

    导入后

    在xml配置文件中,输入Spring的根标签<beans></beans> 然后切换到design视图右击选择 -->namespace-->勾选xsi(这时约束的约束,必须有,控制后面所有)

    -->add-->specify new namespace -->location hint (把刚才添加的约束导入)-->把去约束文件名的网址复制到 namespace name -->prefix随便起个名(一般叫约束名

    )

    最后注意:beans不要有prefix 要设置为空,否则没有标签提示

    <?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop"
        xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="http://www.springframework.org/schema/beans 
                            http://www.springframework.org/schema/beans/spring-beans-4.2.xsd 
                            http://www.springframework.org/schema/aop 
                            http://www.springframework.org/schema/aop/spring-aop-4.2.xsd 
                            http://www.springframework.org/schema/context 
                            http://www.springframework.org/schema/context/spring-context-4.2.xsd 
                            http://www.springframework.org/schema/tx 
                            http://www.springframework.org/schema/tx/spring-tx-4.2.xsd ">
                            
        <context:component-scan base-package="com.swift"></context:component-scan>
        <context:property-placeholder location="classpath:db.properties"/>
        
        <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
            <property name="driverClass" value="${driverClass}"></property>
            <property name="jdbcUrl" value="${jdbcUrl}"></property>
            <property name="user" value="${user}"></property>
            <property name="password" value="${password}"></property>
        </bean>
        
        
    </beans>

    <context:property-placeholder location="classpath:db.properties"/>

    扫描src目录下的properties文件使用${key}加载value 据说是spring的el语言spel

    感觉这里直接写也可以,单独拿到properties文件里可能不会感觉乱哄哄一堆

    测试结果

    package com.swift.jdbctemplate;
    
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.List;
    
    import javax.sql.DataSource;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import org.springframework.jdbc.core.BeanPropertyRowMapper;
    import org.springframework.jdbc.core.JdbcTemplate;
    
    public class DemoJdbcTemplate {
    
        private static ApplicationContext context=new ClassPathXmlApplicationContext("applicationContext.xml");
        private static DataSource dataSource = (DataSource) context.getBean("dataSource");
        private static JdbcTemplate jdbcTemplate=new JdbcTemplate(dataSource);
        
        public static void main(String[] args) throws SQLException {
        
            User user=new User(null,null,"甲鱼不是龟","456","0");
            add(user);
            List<User> users=new ArrayList<>();
            users=findAll();
            System.out.println(users);
            user=findById(23l);
            System.out.println(user);
        }
    
        private static User findById(long l) {
            return jdbcTemplate.queryForObject(
                    "select * from sys_user where user_id=?", new BeanPropertyRowMapper<User>(User.class),l);
        }
    
        private static List<User> findAll() {
            
            return jdbcTemplate.query("select * from sys_user", new BeanPropertyRowMapper<User>(User.class));
        }
    
        private static void add(User user) {
    
            jdbcTemplate.update("insert into sys_user values(?,?,?,?,?)",
                    null,null,user.getUser_name(),user.getUser_password(),user.getUser_state());
            System.out.println("插入记录成功");
        }
    
    }
  • 相关阅读:
    Prestashop-1.6.1.6-zh_CN (Openlogic CentOS 7.2)
    青石B2C商城
    装ubuntu的坑
    欧式空间和欧式距离、曼哈顿距离
    卷积神经网络入门
    pointnet++论文的翻译
    度量空间
    ppt演讲者视图不可用的解决办法
    pointnet
    Your CPU supports instructions that this TensorFlow binary was not compiled to use: AVX2 AVX512F FMA
  • 原文地址:https://www.cnblogs.com/qingyundian/p/9094572.html
Copyright © 2020-2023  润新知