以User為操作對象

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;}@Overridepublic 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

這個注意ResultSet 是一個帶指針的結果集,指針開始指向第一個元素的前一個(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整合了連接數據庫的Connection ,提供更快速的連接

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);} }

并可以直接加載xml配置文件,強于(DBCP連接池,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的殺手锏QueryRunner?

可以使用?了,放置惡意注意,也提供自動增加' '符號,這個要注意

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);}//通過Id查找User user=findById(9l);System.out.println(user);//更新user.setUser_name("韓梅梅");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 有個核心配置文件

<?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"><!-- 約束在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:資料\hibernate-release-5.0.7.Final\project\etc\hibernate.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><!-- 獲得當前session放在當前線程中 --><!-- <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>
這個是使用Hibernate自帶的c3p0功能,不需要自己寫c3p0.xml文件,但除了需要c3p0的jar包,還需要Hibernate自帶的jar包,可以在hibernate包的lib->optional->c3p0中找到，
此文件夾中這兩個jar：c3p0-0.9.1.jar和hibernate-c3p0-4.2.1.Final.jar都要用,否則異常
Could not instantiate connection provider [org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider]

還有個實體類的映射文件

<?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"> <!-- 約束在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>

連接數據庫是通過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()是創建Configuration類對象，調用里面的configure方法，讀取配置信息，方法返回的又是Configuration類型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;}}

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使用Spring的jdbcTemplate

關于倒包

Spring 總共有20個包看需要導入,其他還有spring的官方擴展包 (整合的較常用的一些,可根據功能導入)

這里只要實現數據庫,所以,倒spring的4個核心包beans context core expression 2個日志log4j commons-loging(可不倒)

c3p0要倒 連接數據庫mysql-connector-java ?還有Spring的spring-jdbc 事務spring-tx 用注解要spring-aop

配置文件菜單法生成

applicationContext.xml(非官方約定俗成的,其實叫什么都可以)

約束如果不想拷貝,可以用菜單導入 window --> preferences -->搜索(xml catalog) -->add-->file system(注意:把location最后的約束文件名復制到key的最后)

導入后

在xml配置文件中,輸入Spring的根標簽<beans></beans> 然后切換到design視圖右擊選擇 -->namespace-->勾選xsi(這時約束的約束,必須有,控制后面所有)

-->add-->specify new namespace -->location hint (把剛才添加的約束導入)-->把去約束文件名的網址復制到 namespace name -->prefix隨便起個名(一般叫約束名

)

最后注意:beans不要有prefix 要設置為空,否則沒有標簽提示

<?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"/>

掃描src目錄下的properties文件使用${key}加載value 據說是spring的el語言spel

感覺這里直接寫也可以,單獨拿到properties文件里可能不會感覺亂哄哄一堆

測試結果

?

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,"甲魚不是龜","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("插入記錄成功");}}

?

轉載于:https://www.cnblogs.com/qingyundian/p/9094572.html

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