spring自学历程

spring几大核心功能

1.IOC/DI(控制反转/依赖注入)

IOC是什么？IOC完成的事情是原先程序员主动通过new实例化对象的事情，转交给spring负责

IOC最大的作用是：解耦，程序员不需要管理对象，解除了对象管理和程序员之间的耦合

2.AOP(面向切面编程)

3.声明式事务

spring框架重要的概念：容器(container):spring当作一个容器

Spring 框架采用分层架构，根据不同的功能被划分成了多个模块，这些模块大体可分为 Data Access/Integration、Web、AOP、Aspects、Messaging、Instrumentation、Core Container 和 Test(见上图)

详细见：http://c.biancheng.net/view/4242.html

spring创建对象的三种方式

1.通过构造方法创建

　　1.1　在applicationContext.xml中设置哪个构造方法创建对象

<bean id="pro" class="com.spring.po.People"></bean>

<bean id="pro2" class="com.spring.po.People">

<constructor-arg index="0" name="id" type="int" value="2"></constructor-arg>
<constructor-arg index="1" name="name" type="String" value="有参构造实例"></constructor-arg>
</bean>

　　1.2　如果设定的条件匹配多个构造方法，则执行最后的构造方法

　　1.3　index：参数的索引，从0开始，name：参数名，type：类型(区分关键字和封装类，例 int和integer)

2.实例工厂

　　2.1　工厂设计模式：帮助创建类对象，一个工厂可以生产多个对象

　　2.2　实例工厂：需要先创建工厂，才能生产对象，然后在xml中配置工厂对象和需要创建的对象

package com.spring.po;

public class PeopleFactory {
    public People newInstance(){
        return new People(3,"实例工厂");
    }
}

     <!-- 实例工厂实现实例 -->
     <bean id="factory" class="com.spring.po.PeopleFactory"></bean>
     <bean id="pro3" factory-bean="factory" factory-method="newInstance"></bean>

3.静态工厂：编写一个静态工厂，在方法上添加static

package com.spring.po;

public class PeopleStaticFactory {
    public static People newInstance(){
        return new People(4, "静态");
    }

}

<!-- 静态工厂实例实例 -->
<bean id="pro4" class="com.spring.po.PeopleStaticFactory" factory-method="newInstance"></bean>

具体案例

IDE：myeclipse2017

jar包：spring4个基础jar包(本案例使用5.2版本)+Commons-logging的jar包

新建项目spring01，项目结构图如下

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd">
        <!-- 
            id：表示对象标识
            class：创建哪个类的对象
         -->
      <!-- 无参实例 -->
     <bean id="pro" class="com.spring.po.People"></bean>
     <!-- 有参实例 -->
     <bean id="pro2" class="com.spring.po.People">
         <!-- ref：引用另一个bean        value：基本数据类型或String等 -->
         <constructor-arg index="0" name="id" type="int" value="2"></constructor-arg>
         <constructor-arg index="1" name="name" type="String" value="有参构造实例"></constructor-arg>
     </bean>
     
     <!-- 实例工厂实现实例 -->
     <bean id="factory" class="com.spring.po.PeopleFactory"></bean>
     <bean id="pro3" factory-bean="factory" factory-method="newInstance"></bean>
     
     <!-- 静态工厂实例实例 -->
     <bean id="pro4" class="com.spring.po.PeopleStaticFactory" factory-method="newInstance"></bean>
</beans>

com.spring.po包

People.java

package com.spring.po;

public class People {
    private int id;
    private String name;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Override
    public String toString() {
        return "People [id=" + id + ", name=" + name + "]";
    }
    
    
    public People() {
        super();
    }
    public People(int id,String name){
        this.id=id;
        this.name=name;
        System.out.println("有参构造函数");
    }
}

PeopleFactory.java

package com.spring.po;

public class PeopleFactory {
    public People newInstance(){
        return new People(3,"实例工厂");
    }
}

PeopleStaticFactory.java

package com.spring.po;

public class PeopleStaticFactory {
    public static People newInstance(){
        return new People(4, "静态");
    }

}

com.spring.test包

Test.java

package com.spring.test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.spring.po.People;

public class Test {
    public static void main(String[] args) {
        ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");
        People people= ac.getBean("pro",People.class);
        people.setId(1);
        people.setName("测试");
        
        People people2=ac.getBean("pro2",People.class);
        
        People people3=ac.getBean("pro3",People.class);
        
        People people4=ac.getBean("pro4",People.class);
        
        System.out.println(people);
        System.out.println(people2);
        System.out.println(people3);
        System.out.println(people4);
    }
}

运行结果如下

使用spring简化mybatis

IDE：myeclipse2017

数据库的airport表数据

项目具体代码在后面

1.导入mybatis所有jar包和spring基本jar包，spring-idbc,spring-tx,spring-aop,spring-web

2.编写spring配置文件applicationContext.xml

3.编写代码

　　3.1　正常编写po(实体类)

　　3.2　编写Mapper包下时必须使用接口绑定方案或注解方案(必须有接口)

　　3.3　正常编写service接口和service实现类(impl)

　　　　3.3.1　需要在service实现类中声明Mapper接口对象，并生成get/set方法

　　3.4　spring无法管理servlet

案例

结构图

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd">
    <!-- 数据源封装类，获取数据库连接  -->
    <bean id="dataSouce" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
        <property name="url" value="jdbc:mysql://localhost:3306/test?serverTimezone=UTC"></property>
        <property name="username" value="root"></property>
        <property name="password" value="123456"></property>
    </bean>
    <!-- 创建SqlSessionFactory对象 -->
    <bean id="factory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 数据库连接信息，来源于dataSouce -->
        <property name="dataSource" ref="dataSouce"></property>
    </bean>
    <!-- 扫描器相当于mybatis.xml中的Mapper下的backage标签 ，扫描com.spring.mapper后会给对应的接口创建对象-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 要扫描的包 -->
        <property name="basePackage" value="com.spring.mapper"></property>
        <!-- 和Factory产生关系 -->
        <property name="sqlSessionFactory" ref="factory"></property>
    </bean>
    <!-- 由spring管理service -->
    <bean id="airportService" class="com.spring.service.impl.AirportServiceImpl">
        <property name="airportMapper" ref="airportMapper"></property>
    </bean>
</beans>

com.spring.po包

Airport.java

package com.spring.po;

public class Airport {
    private int id;
    private String portName;
    private String cityName;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getPortName() {
        return portName;
    }
    public void setPortName(String portName) {
        this.portName = portName;
    }
    public String getCityName() {
        return cityName;
    }
    public void setCityName(String cityName) {
        this.cityName = cityName;
    }
    
    @Override
    public String toString() {
        return "Airport [id=" + id + ", portName=" + portName + ", cityName=" + cityName + "]";
    }
    
    
}

com.spring.mapper包

AirportMapper.java

package com.spring.mapper;

import java.util.List;

import org.apache.ibatis.annotations.Select;

import com.spring.po.Airport;

public interface AirportMapper {
    @Select("select * from airport")
    List<Airport> selAll();
}

com.spring.service包

AirportService.java

package com.spring.service;

import java.util.List;

import com.spring.po.Airport;

public interface AirportService {
    List<Airport> show();
}

com.spring.service.impl包

AirportServiceImpl.java

package com.spring.service.impl;

import java.util.List;

import com.spring.mapper.AirportMapper;
import com.spring.po.Airport;
import com.spring.service.AirportService;

public class AirportServiceImpl implements AirportService{
    private AirportMapper airportMapper;
    

    public AirportMapper getAirportMapper() {
        return airportMapper;
    }


    public void setAirportMapper(AirportMapper airportMapper) {
        this.airportMapper = airportMapper;
    }


    @Override
    public List<Airport> show() {
        return airportMapper.selAll();
    }
    
}

com.spring.test包

Test.java

可以测试运行test

package com.spring.test;

import java.util.List;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.spring.po.Airport;
import com.spring.service.impl.AirportServiceImpl;

public class Test {
    public static void main(String[] args) {
        ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");
//        String [] names=ac.getBeanDefinitionNames();
//        for (String string : names) {
//            System.out.println(string);
//        }
        
        AirportServiceImpl bean= ac.getBean("airportService",AirportServiceImpl.class);
        List<Airport> list=bean.show();
//        System.out.println(list);
        for (Airport airport : list) {
            System.out.println(airport);
        }
    }
}

com.spring.servlet包

AirportServlet.java

package com.spring.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.spring.service.AirportService;
import com.spring.service.impl.AirportServiceImpl;

@WebServlet("/airport")
public class AirportServlet extends HttpServlet {
    private AirportService airportService;
    
    

    @Override
    public void init() throws ServletException {
        //对service实例化
        WebApplicationContext ac=WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
        airportService=ac.getBean("airportService",AirportServiceImpl.class);
    }



    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setAttribute("list", airportService.show());
        req.getRequestDispatcher("index.jsp").forward(req, resp);
    }
    
    

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
    version="3.1">
    <!-- 上下文参数 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <!-- spring配置文件 -->
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
    <!--封装了一个监听器，帮助加载spring的配置文件  -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
</web-app>

index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    
    <title>spring简化mybatis</title>
  </head>
  
  <body>
      <c:forEach items="${list }" var="as" >
          ${as.id }    ${as.portName }    ${as.cityName }<br/>
      </c:forEach>
  </body>
</html>

运行结果如下

AOP初使用

前置通知和后置通知

新建项目，结构图如下

applicationContext.xml

　　 * 号：通配符，匹配任意方法名，任意类名，任意一级包名

　　如果希望匹配任意方法参数，使用　(..)

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop 
        http://www.springframework.org/schema/aop/spring-aop.xsd">
     <!-- 配置通知类对象，在切面中引入 -->
    <bean id="mybefore" class="com.spring.advice.MyBeforeAdvice"></bean>
    <bean id="myafter" class="com.spring.advice.MyAfterAdvice"></bean>
    <!-- 配置切面 -->
    <aop:config>
        <!-- 配置切点 -->
        <aop:pointcut expression="execution(* com.spring.test.Demo.demo2())" id="mypoint"/>
        <!-- 通知 -->
        <aop:advisor advice-ref="mybefore" pointcut-ref="mypoint"/>
        <aop:advisor advice-ref="myafter" pointcut-ref="mypoint"/>
    </aop:config>
    <!-- 配置Demo类，测试使用 -->
    <bean id="demo" class="com.spring.test.Demo"></bean>
</beans>

com.spring.advice包

MyAfterAdvice.java

　　arg0：切点方法返回值

　　arg1：切点方法对象

　　arg2：切点方法参数

　　arg3：切点方法所在类对象

package com.spring.advice;

import java.lang.reflect.Method;

import org.springframework.aop.AfterReturningAdvice;

public class MyAfterAdvice implements AfterReturningAdvice{

    @Override
    public void afterReturning(Object arg0, Method arg1, Object[] arg2, Object arg3) throws Throwable {
        System.out.println("执行后置通知");
        
    }
    
}

MyBeforeAdvice.java

　　arg0：切点方法对象Method

　　arg1：切点方法参数

　　arg2：切点在哪个对象中

package com.spring.advice;

import java.lang.reflect.Method;

import org.springframework.aop.MethodBeforeAdvice;

public class MyBeforeAdvice implements MethodBeforeAdvice {

    @Override
    public void before(Method arg0, Object[] arg1, Object arg2) throws Throwable {
        System.out.println("执行前置通知");
        
    }
    
}

com.spring.test包

Demo.java

package com.spring.test;

public class Demo {
    public void demo1(){
        System.out.println("demo1");
    }
    
    public void demo2(){
        System.out.println("demo2");
    }
    
    public void demo3(){
        System.out.println("demo3");
    }
}

Test.java

package com.spring.test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {
    public static void main(String[] args) {
//        Demo demo=new Demo();
//        demo.demo1();
//        demo.demo2();
//        demo.demo3();
        
        ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");
        Demo demo=ac.getBean("demo",Demo.class);
        demo.demo1();
        demo.demo2();
        demo.demo3();
    }
}

结果如下

异常通知（Aspectj方式）

新建类，写任意名称的方法

package com.spring.advice;

public class MyThrowAdvice {
    public void  myexception(Exception e){
        System.out.println("执行异常通知,异常message："+e.getMessage());
    }
}

在spring配置文件中配置

　　<aop:cnfig>中的ref属性表示：方法在哪个类中

　　<aop:after-throwing>表示异常通知

　　method：当触发这个通知，调用哪个方法

　　throuing：异常对象名，若使用throwing，则值必须和通知中的方法参数名相同(可以不在通知中声明异常对象，throwing可省略)

    <bean id="mythrow" class="com.spring.advice.MyThrowAdvice"></bean>
    <aop:config>
        <aop:aspect ref="mythrow">
            <aop:pointcut expression="execution(* com.spring.test.Demo.demo1())" id="mypoint"/>
            <aop:after-throwing method="myexception" pointcut-ref="mypoint" throwing="e"/>
        </aop:aspect>
    </aop:config>
    <bean id="demo" class="com.spring.test.Demo"></bean>

demo1()方法

    public void demo1() throws Exception{
        int num=5/0;
        System.out.println("demo1");
    }

Test类main

        ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");
        Demo demo=ac.getBean("demo",Demo.class);
        try {
            demo.demo1();
        } catch (Exception e) {
            
        }

结果如下

环绕通知

把前置通知和后置通知都写到一个通知中，组成了环绕通知

新建类，实现MethodInterceptor

package com.spring.advice;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;

public class MyArround implements MethodInterceptor {

    @Override
    public Object invoke(MethodInvocation arg0) throws Throwable {
        System.out.println("环绕-前置");
        Object result=arg0.proceed();
        System.out.print("环绕-后置");
        return result;
    }
    

}

xml配置文件

    <!-- 环绕通知 -->
    <bean id="myarround" class="com.spring.advice.MyArround"/>
    <aop:config>
        <aop:pointcut expression="execution(* com.spring.test.Demo.demo2())" id="mypoint"/>
        <aop:advisor advice-ref="myarround" pointcut-ref="mypoint"/>
    </aop:config>
    
    <!-- 配置Demo类，测试使用 -->
    <bean id="demo" class="com.spring.test.Demo"></bean>

main()方法

    public static void main(String[] args) {
//        Demo demo=new Demo();
//        demo.demo1();
//        demo.demo2();
//        demo.demo3();
        
        ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");
        Demo demo=ac.getBean("demo",Demo.class);
        /*try {
            demo.demo1();
        } catch (Exception e) {
            
        }*/
        demo.demo2();
//        demo.demo3();
    }

结果如下

自定义通知

新建类，MyAdvice.java

package com.spring.advice;

import org.aspectj.lang.ProceedingJoinPoint;

public class MyAdvice {
    public void mybefore(){
        System.out.println("前置通知");
    }
    
    public void myafter(){
        System.out.println("后置通知1");
    }
    
    public void myaftering(){
        System.out.println("后置通知2");
    }
    
    public void mythrow(){
        System.out.println("异常通知");
    }
    
    public Object myarround(ProceedingJoinPoint p) throws Throwable{
        System.out.println("执行环绕");
        System.out.println("执行环绕前置");
        Object result=p.proceed();
        System.out.println("环绕后置");
        return result;
    }
}

xml配置文件

    <bean id="myadvice" class="com.spring.advice.MyAdvice"></bean>
    <aop:config>
        <aop:aspect ref="myadvice">
            <aop:pointcut expression="execution(* com.spring.test.Demo.demo1())" id="mypoint"/>
            <!-- 前置通知 -->
            <aop:before method="mybefore" pointcut-ref="mypoint"/>
            <!-- 后置通知：alter有异常，依旧执行 -->
            <aop:after method="myafter" pointcut-ref="mypoint"/>
            <!-- 后置通知：alter-returning有异常，不执行 -->
            <aop:after-returning method="myaftering" pointcut-ref="mypoint"/>
            <!-- 异常通知 -->
            <aop:after-throwing method="mythrow" pointcut-ref="mypoint"/>
            <!-- 环绕通知 -->
            <aop:around method="myarround" pointcut-ref="mypoint"/>
        </aop:aspect>
    </aop:config>
    
    <!-- 配置Demo类，测试使用 -->
    <bean id="demo" class="com.spring.test.Demo"></bean>

demo类

public void demo1() throws Exception{
        int num=5/0;
        System.out.println("demo1");
    }

可注释num=5/0，来显示不同结果

自动注入

在spring配置文件中对象名和ref="id"，id名相同可以使用自动注入，不配置<property/>

2种配置方法

在<bean>中通过autowire="" 　配置，只对这个<bean>生效

在<beans>中通过default-autowire="“　　配置，表示当前文件中所有<bean>都是全局配置内容

autowire=""，可取值

　　default：默认值，根据全局default-autowire="“值，默认全局和局部都没有配置情况下，相当”no“

　　no：不自动注入

　　byName：通过名称自动注入，在spring容器中找类的id

　　byType：根据类型注入(使用byType，则在spring容器不可以出现相同类型的<bean>)

　　constructor：根据构造方法注入

　　　　提供对应参数的构造方法(构造方法参数中包含注入对象那个)

　　　　底层使用byName,构造方法参数名和其他<bean>的id相同

练习

新建项目，项目结构图如下

lib

数据库

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
    version="3.1">
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
</web-app>

log4j.properties

# Global logging configuration
log4j.rootLogger=INFO,stdout,R
# MyBatis logging configuration...
log4j.logger.com.mybatis=DEBUG
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

log4j.appender.R=org.apache.log4j.DailyRollingFileAppender
log4j.appender.R.File=D:\temp\logs\qc.log   
log4j.appender.R.layout=org.apache.log4j.PatternLayout   
1log4j.appender.R.layout.ConversionPattern=%5p [%t] - %m%n

applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xsi:schemaLocation="http://www.springframework.org/schema/beans
https://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/aop
https://www.springframework.org/schema/aop/spring-aop.xsd"
default-autowire="byName">

<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
<property name="url" value="jdbc:mysql://localhost:3306/test?serverTimezone=UTC"></property>
<property name="username" value="root"></property>
<property name="password" value="123456"></property>
</bean>

<bean id="factory" class="org.mybatis.spring.SqlSessionFactoryBean">



<property name="typeAliasesPackage" value="com.spring.po"></property>
</bean>

<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">

<property name="basePackage" value="com.spring.mapper"></property>

<property name="sqlSessionFactory" ref="factory"></property>
</bean>

<bean id="usersService" class="com.spring.service.impl.UsersServiceImpl">

</bean>

<bean id="mybefore" class="com.spring.advice.MyBefore"></bean>
<bean id="myAfter" class="com.spring.advice.MyAfter"></bean>

<aop:aspectj-autoproxy proxy-target-class="true"></aop:aspectj-autoproxy>
<aop:config>
<aop:pointcut expression="execution(* com.spring.service.impl.UsersServiceImpl.login(..))" id="mypoint"/>
<aop:advisor advice-ref="mybefore" pointcut-ref="mypoint"/>
<aop:advisor advice-ref="myAfter" pointcut-ref="mypoint"/>
</aop:config>
</beans>

com.spring.po包

Users.java

package com.spring.po;

public class Users {
    private int id;
    private String username;
    private String password;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    
    
}

com.spring.mapper包

UsersMapper.java

package com.spring.mapper;

import com.spring.po.Users;

public interface UsersMapper {
    Users selByUsers(Users users);
}

UsersMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.spring.mapper.UsersMapper">
    <select id="selByUsers" parameterType="users" resultType="users">
        select * from users where username=#{username} and password=#{password}
    </select>
</mapper>

com.spring.service包

UsersService.java

package com.spring.service;

import com.spring.po.Users;

public interface UsersService {
    Users login(Users users);
}

com.spring.service.impl包

package com.spring.service.impl;

import com.spring.mapper.UsersMapper;
import com.spring.po.Users;
import com.spring.service.UsersService;

public class UsersServiceImpl implements UsersService {
    private UsersMapper usersMapper;
    
    

    public UsersMapper getUsersMapper() {
        return usersMapper;
    }



    public void setUsersMapper(UsersMapper usersMapper) {
        this.usersMapper = usersMapper;
    }



    @Override
    public Users login(Users users) {
        return usersMapper.selByUsers(users);
    }
    
}

com.spring.servlet包

LoginServlet.java

package com.spring.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.spring.po.Users;
import com.spring.service.UsersService;
import com.spring.service.impl.UsersServiceImpl;

@WebServlet("/login")
public class LoginServlet extends HttpServlet {
    private UsersService usersService;

    @Override
    public void init() throws ServletException {
        WebApplicationContext wac=WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
        usersService=wac.getBean("usersService",UsersServiceImpl.class);
    }

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("utf-8");
        Users users=new Users();
        users.setUsername(req.getParameter("username"));
        users.setPassword(req.getParameter("password"));
        Users user=usersService.login(users);
        if(user!=null){
            resp.sendRedirect("main.jsp");
        }
        else {
            resp.sendRedirect("login.jsp");
        }
    }
    
    
    
}

com.spring.test包

Test　　测试用的

    package com.spring.test;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {
    public static void main(String[] args) {
        ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");
        String [] names=ac.getBeanDefinitionNames();
        for (String string : names) {
            System.out.println(string);
        }
    }
}

com.spring.advice包

MyAfter.java

package com.spring.advice;

import java.lang.reflect.Method;

import org.apache.log4j.Logger;
import org.springframework.aop.AfterReturningAdvice;

import com.spring.po.Users;

public class MyAfter implements AfterReturningAdvice {

    @Override
    public void afterReturning(Object arg0, Method arg1, Object[] arg2, Object arg3) throws Throwable {
        Logger logger=Logger.getLogger(MyAfter.class);
        Users users=(Users)arg2[0];
        if(arg0!=null){
            logger.info(users.getUsername()+"登录成功！");
        }else {
            logger.info(users.getUsername()+"登录失败！");
        }
        
    }
    
}

MyBefore.java

package com.spring.advice;

import java.lang.reflect.Method;
import java.util.Date;

import org.apache.log4j.Logger;
import org.springframework.aop.MethodBeforeAdvice;

import com.spring.po.Users;

public class MyBefore implements MethodBeforeAdvice  {

    @Override
    public void before(Method arg0, Object[] arg1, Object arg2) throws Throwable {
        Users users=(Users)arg1[0];
        Logger logger=Logger.getLogger(MyBefore.class);
        logger.info(users.getUsername()+"在"+new Date().toLocaleString()+"进行登录");
    }
    
}

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <title>My JSP 'login.jsp' starting page</title>
  </head>
  
  <body>
  <form action="login" method="post">
      用户名：<input type="text" name="username"><br>
      密码:<input type="password" name="password"><br/>
      <input type="submit" value="登录">
  </form>
  </body>
</html>

运行

spring中加载properties文件

1.在src下新建xxx.properties文件

2.在spring配置文件中引入xmlns:context，在下面添加，如果需要加载多个配置文件，用逗号分隔

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

3.添加了属性文件，并且在<beans>中开启自动注入，需要注意的地方

　　3.1 SqlSessionFactoryBean的id不能叫做sqlSessionFactory

　　3.2 修改扫描器(MapperScannerConfigurer)，把原来ref引用替换value赋值，自动注入只能影响ref，不会影响value赋值

    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 要扫描的包 -->
        <property name="basePackage" value="com.spring.mapper"></property>
        <!-- 和Factory产生关系 -->
        <property name="sqlSessionFactoryBeanName" value="factory"></property>
    </bean>

4.在被spring管理的类通过@Value("${key}")取出properties中的内容

　　4.1添加注解扫描

<context:component-scan base-package="com.spring.service.impl"></context:component-scan>

　　4.2在类中添加

　　　　key和变量名可以不相同

　　　　变量类型任意，只要保证key对应的value能转换成这个类型就可以

示例

在上个项目中src下添加db.properties和second.properties

second.properties

my.demo=hello
my.demo1=123

db.properties

jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test?serverTimezone=UTC
jdbc.username=root
jdbc.pwd=123456

修改UsersServiceImpl.java

package com.spring.service.impl;

import org.springframework.beans.factory.annotation.Value;

import com.spring.mapper.UsersMapper;
import com.spring.po.Users;
import com.spring.service.UsersService;

public class UsersServiceImpl implements UsersService {
    @Value("${my.demo}")
    private String test;
    
    @Value("${my.demo1}")
    private String test1;
    
    private UsersMapper usersMapper;

    public UsersMapper getUsersMapper() {
        return usersMapper;
    }

    public void setUsersMapper(UsersMapper usersMapper) {
        this.usersMapper = usersMapper;
    }

    @Override
    public Users login(Users users) {
        System.out.println("输出："+test+"    "+test1);
        
        return usersMapper.selByUsers(users);
    }

}

修改applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop
        https://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd"
        default-autowire="byName">
    <context:property-placeholder location="classpath:db.properties,classpath:second.properties"/>
    <context:component-scan base-package="com.spring.service.impl"></context:component-scan>
    <!-- 数据源封装类，获取数据库连接  -->
    <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="${jdbc.driverClassName}"></property>
        <property name="url" value="${jdbc.url}"></property>
        <property name="username" value="${jdbc.username}"></property>
        <property name="password" value="${jdbc.pwd}"></property>
    </bean>
    <!-- 创建SqlSessionFactory对象 -->
    <bean id="factory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 数据库连接信息，来源于dataSouce -->
         <!-- <property name="dataSource" ref="dataSource"></property> -->
        <!-- 起别名 -->
        <property name="typeAliasesPackage" value="com.spring.po"></property>
    </bean>
    <!-- 扫描器相当于mybatis.xml中的Mapper下的backage标签 ，扫描com.spring.mapper后会给对应的接口创建对象-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!-- 要扫描的包 -->
        <property name="basePackage" value="com.spring.mapper"></property>
        <!-- 和Factory产生关系 -->
        <!-- <property name="sqlSessionFactory" ref="factory"></property> -->
        <property name="sqlSessionFactoryBeanName" value="factory"></property>
    </bean>
    <!-- 由spring管理service -->
    <bean id="usersService" class="com.spring.service.impl.UsersServiceImpl">
        <!-- <property name="usersMapper" ref="usersMapper"></property>  -->
    </bean>
    
    <bean id="mybefore" class="com.spring.advice.MyBefore"></bean>
    <bean id="myAfter" class="com.spring.advice.MyAfter"></bean>
    <!-- aop -->
    <aop:aspectj-autoproxy proxy-target-class="true"></aop:aspectj-autoproxy>
    <aop:config>
        <aop:pointcut expression="execution(* com.spring.service.impl.UsersServiceImpl.login(..))" id="mypoint"/>
        <aop:advisor advice-ref="mybefore" pointcut-ref="mypoint"/>
        <aop:advisor advice-ref="myAfter" pointcut-ref="mypoint"/>
    </aop:config>
</beans>

运行登录，控制台结果如下

scope属性

1.<bean>的属性

2.作用：控制对象有效范围(单例，多例)

3.<bean>标签对应的对象默认是单例的，无论获取多少次，都是一个对象

4.scope可取值

　　singleton　　默认值，单例

　　prototype　　多例，每次获取重新实例化

　　request　　每次请求重新实例化

　　session　　每次会话对象内，对象内是单例的

　　application　　在application对象内是单例的

spring中常用的两种事务配置方式以及事务的传播性，隔离性

参考https://www.cnblogs.com/dj66194/p/7654555.html，感谢“还有梦”

spring中常用注解

1.@Component：创建类对象，相当于配置<bean>

2.@Service：与Component功能相同，写在serviceImpl类上

3.@Repository：与Component功能相同，写在数据访问层类上

4.@Controller：与Component功能相同，写在控制器类上

5.@Resource：不需要写对象的get/set，java中的注解，默认按照byName注入，如果没有名称对象，则按照byType注入，建议把对象名称和spring容器中对象名相同

6.@Autowired：不需要写对象的get/set，spring注解，默认按照byType注入

7.@Value()：获取properties文件内容

8.@Pointcut()：定义切点

9.@ASpect()：定义切面类

10.@Before()：前置通知

11.@Alter：后置通知

12.@AlterReturning：后置通知，切点须正确执行

13.@AlterThrowing：异常通知

14.@Around：环绕通知

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原文地址：https://www.cnblogs.com/qc-wh/p/11759792.html