1. day01 - Framework

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8,day-08-SSM

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Constant/ chengheng@tedu.cn

Course Topic: SSM

Review: MVC

Design Mode

The performance of the singleton pattern is: Only one instance (object) of a class can exist at any time!

Assume:

Then:

Spring Framework

3Add Spring profile source: Profiles can be downloaded from FTP to target location: src\mainresouces

4 Create a Spring-managed class, which can be any class such as Create User Class

About close() of ApplicationContext

Notes on Different Versions from Teaching Versions

How to get objects using Spring

By parameterless construction

By Static Factory Method

Get an example object: Calendar calendar = ctx.getBean("calendar", Calendar.class);

-------------------------------------------------------------------------------------------------------------------

By Instance Factory Method

Scope of beans managed through Spring

Life cycle of beans managed through Spring

Development steps:

 

No prompts when writing XML files

[Review] Memory leaks and memory overflows

[Review] Abnormal Architecture

 

Design Mode-Singleton-Lazy Singleton

User registration for MVC

Rough process

Simulated implementation of code in Model

public class UserService {
private UserDao userDao;
public void reg(User user) {
dao.insert(user);
}
}
public class UserDao {
public void insert(User user) {
// Access database, add data
}
}

Injecting values of attributes directly through the Set method of attributes in Spring-managed beans

Application Scenarios

Development steps

Injecting values of attributes through construction methods in Spring-managed beans

Development steps

Injecting base values directly into Spring-managed beans

What are the base values

How to set the base value

3. Testing in Test Class

4. See if the result was injected successfully:

Direct injection of collection type values into Spring managed beans

Use set injection to assign values to attributes:

Inject Properties type values directly into Spring managed beans

Development steps

[Review] List and Set

Common ground

• All subinterfaces of Collection

Difference

• List collection is ordered/sequential, Set collection is unordered/hashed
• Data in a List collection is allowed to be duplicated, while data in a Set collection is unique

Criteria for identical/unique data in a Set

[Review] ArrayList and LinkedList

[Review] HashSet and TreeSet

In fact, when injecting values, arrays and lists can be confused! That is, even if an attribute is an array type, when injecting values, you can refer to a set of lists designed with a <util:List>ref! Of course, the data types must match!

Spring expressions can be applied to Spring's XML configuration files.

A Spring expression can be used to reference an attribute value of another Bean, or an element in a collection in another Bean when injecting a value...

Use condition: One BeanX has been injected with a value, and another BeanY has some values from BeanX.

The basic format of a Spring expression is: #{id.property name of the referenced bean}

If an element in an array or a List collection is referenced, #{id of the referenced bean.Array name or collection name [subscript]}

5.Get it in the applicationContext.xml file using a Spring expression

Spring's auto-assembly manifests itself as values that can be automatically injected without needing to be injected in XML via Set or construction methods!

Component Scan for Spring

What is Component Scan

Why use component scanning

Basic development steps

General implementation principles of basic projects

Customize ID for Bean

SpringMVC Principle

SpringMVC process

Component description:

Analysis:

M-Model (Complete Business Logic: javaBean Composition, service+dao+entity)

V-View View (Show the interface jsp, html...)

C-Controller Controller Controller (Receive Request - > Call Model - > Dispatch Page Based on Results)

 

What is springMVC:

Spring MVC is an open source framework for MVC. Spring MVC=struts2+spring, Spring MVC is equivalent to the integration of Struts2 and sring, but here is a puzzle: what is the relationship between spring MVC and spring? This has a good explanation in Baidu Encyclopedia: meaning that spring MVC is a follow-up product of spring, in fact it is spring on its original basisOn the web, there is also a MVC module for web applications, which can be simply understood as a module of spring (such as AOP, IOC). On the web, it is often said that springMVC and spring integrate seamlessly. In fact, springMVC is a sub-module of spring, so there is no need to integrate with spring at all.

Schematic diagram of SpringMVC:

There may be a lot of confusion when you see this diagram. Now let's take a look at the steps of this diagram: (you can understand the schematic of MVC by comparing it)

Step 1: The user initiates a request to the front-end controller (Dispatcher Servlet)

Step 2: Front End Controller requests the Handler Mappering to find the Handle: Find it through xml configuration or annotations

Step 3: Find the processor mapper (HandlerMappering) and return the execution chain like the front-end controller (HandlerExecutionChain)

Step 4: The front-end controller (Dispatcher Servlet) calls the processor adapter (Handler Adapter) to execute the processor (Handler)

Step 5: Processor adapter to execute Handler

Step 6: Handler finishes executing and returns ModelAndView to the processor adapter

Step 7: The processor adapter returns ModelAndView to the front-end controller

Step 8: Front End Controller requests ViewResolver for view resolution

Step 9: View parser like front-end controller returns to View

Step 10: The front-end controller renders the view

Step 11: Front-end controller responds to user results

Looking at these steps, I believe it's normal for you to feel very confused, but here's the main point to understand the components of springMVC:

Front-end controller (Dispatcher Servlet): Receives requests, responds to results, and is equivalent to the CPU of a computer.

Handler Mapping: Find processors based on URL s

Handler: (Requires a programmer to write code processing logic)

Handler Adapter: Packages the processor as an adapter so that it can support multiple types of processors, analogous to notebook adapters (application of adapter mode)

ViewResovler: View parsing, multiple returned strings, processing, can be parsed into corresponding pages

Preliminary implementation:

1. Project directory:

2. Create a HelloController class and implement the Controller interface:

3. Configuring servlet s in web.xml

4. Configure three components in the applicationContext.xml file:

5. Write a hello.jsp file under WEB-INF on the web to hello world

6. Finish running

Use the @Controller annotation

In the WEB application designed by Spring MVC, the controller class (the one that originally implements Controller) can be annotated with @Controller!

Use the same Controller to handle many different requests

Annotation-based Spring MVC development process

Practice

Get Request Parameters

Get request parameters from HttpRequestServlet

Get request parameter values by adding parameters to the method that handles the request

Receive values for all request parameters directly through Java Bean

Encapsulate through request and forward

Using ModelAndView

Using ModelMap

Use HttpSession

Interface

User Information

Database and Datasheet

What classes are required in the program

What configurations are needed in the program

Development steps

User Information

Database and Datasheet

What classes are required in the program

What configurations are needed in the program

Development steps

Reasonable data forwarding

Solve garbled problems

Interceptor:

Steps for using interceptors

Under what circumstances do interceptors need to be used

Match all resources when configuring interceptors

How to use interceptor exceptions (exclude-mapping)

What is the difference between an interceptor and a filter

Use interceptors to determine login

SimpleMappingExceptionResolver

@ExceptionHandler

Two ways to compare

Forwarding and redirection of Spring MVC

Annotation Driver

SSM Application Setup

1. Deploy Spring + Spring MVC

1. Import Package

   <dependency>
   <groupId>org.mybatis</groupId>
   <artifactId>mybatis</artifactId>
   <version>3.2.8</version>
   </dependency>
   
   <dependency>
   <groupId>mysql-connector-java</groupId>
   <artifactId>mysql-connector-java</artifactId>
   <version>5.1.37</version>
   </dependency>
   
   <dependency>
   <groupId>junit</groupId>
   <artifactId>junit</artifactId>
   <version>4.12</version>
   </dependency>
   
   
   <dependency>
   <groupId>org.mybatis</groupId>
   <artifactId>mybatis-spring</artifactId>
   <version>1.3.1</version>
   </dependency>
   <dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-webmvc</artifactId>
   <version>3.2.8.RELEASE</version>
   </dependency>
   <dependency>
   <groupId>org.springframework</groupId>
   <artifactId>spring-jdbc</artifactId>
   <version>3.2.8.RELEASE</version>
   </dependency>
   <dependency>
   <groupId>commons-dbcp</groupId>
   <artifactId>commons-dbcp</artifactId>
   <version>1.4</version>
   </dependency>

2. Configure the front-end controller web.xml for Spring MVC:
   <servlet>
   <description></description>
   <display-name>DispatcherServlet</display-name>
   <servlet-name>DispatcherServlet</servlet-name>
   <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
   <init-param>
   <param-name>contextConfigLocation</param-name>
   <param-value>classpath:conf/spring-*.xml</param-value>
   </init-param>
   <load-on-startup>1</load-on-startup>
   </servlet>
   <servlet-mapping>
   <servlet-name>DispatcherServlet</servlet-name>
   <url-pattern>*.do</url-pattern>
   </servlet-mapping>

   The Spring Configuration File Village exists in the conf folder and its file name conforms to the spring - *. xml rule.
3. Add database connection parameter file conf / db.properties
   url=jdbc:mysql://localhost:3306/tedustore
   driver=com.mysql.jdbc.Driver
   user=root
   password=root
   initsize=1
   maxsize=5

4. Add database connection pool profile spring-db.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:context="http://www.springframework.org/schema/context"
   xmlns:jdbc="http://www.springframework.org/schema/jdbc"
   xmlns:jee="http://www.springframework.org/schema/jee"
   xmlns:tx="http://www.springframework.org/schema/tx"
   xmlns:aop="http://www.springframework.org/schema/aop"
   xmlns:mvc="http://www.springframework.org/schema/mvc"
   xmlns:util="http://www.springframework.org/schema/util"
   xmlns:jpa="http://www.springframework.org/schema/data/jpa"
   xsi:schemaLocation="
   http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
   http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
   http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
   http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
   http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
   http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
   http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
   http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
   http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">
   <!-- conf/spring-db.xml Connections used to manage databases -->
   <!-- read conf/db.properties -->
   <util:properties id="dbConfig"
   location="classpath:conf/db.properties" />
   <!-- To configure DBCP Required Bean -->
   <!-- various property In name In class set Method name prevails -->
   <bean id="ds"
   class="org.apache.commons.dbcp.BasicDataSource">
   <property name="driverClassName"
   value="#{dbConfig.driver}"/>
   <property name="url"
   value="#{dbConfig.url}"/>
   <property name="username"
   value="#{dbConfig.user}"/>
   <property name="password"
   value="#{dbConfig.password}"/>
   <property name="initialSize"
   value="#{dbConfig.initsize}"/>
   <property name="maxActive"
   value="#{dbConfig.maxsize}"/>
   </bean>
   </beans>

5. Add the Spring MVC configuration file spring-mvc.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:context="http://www.springframework.org/schema/context"
   xmlns:jdbc="http://www.springframework.org/schema/jdbc"
   xmlns:jee="http://www.springframework.org/schema/jee"
   xmlns:tx="http://www.springframework.org/schema/tx"
   xmlns:aop="http://www.springframework.org/schema/aop"
   xmlns:mvc="http://www.springframework.org/schema/mvc"
   xmlns:util="http://www.springframework.org/schema/util"
   xmlns:jpa="http://www.springframework.org/schema/data/jpa"
   xsi:schemaLocation="
   http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
   http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
   http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
   http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
   http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
   http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
   http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
   http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
   http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">
   <!-- conf/spring-mvc.xml For management MVC Configuration -->
   <context:component-scan
   base-package="cn.tedu.spring" />
   <mvc:annotation-driven/>
   <bean
   class="org.springframework.web.servlet.view.InternalResourceViewResolver">
   <property name="prefix" value="/WEB-INF/jsp/"></property>
   <property name="suffix" value=".jsp"></property>
   </bean>
   </beans>

6. Deployment Test...

2. Deploy Spring MyBatis

1. Import package (omitted)
2. Add Spring MyBatis configuration file spring-mybatis.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:context="http://www.springframework.org/schema/context"
   xmlns:jdbc="http://www.springframework.org/schema/jdbc"
   xmlns:jee="http://www.springframework.org/schema/jee"
   xmlns:tx="http://www.springframework.org/schema/tx"
   xmlns:aop="http://www.springframework.org/schema/aop"
   xmlns:mvc="http://www.springframework.org/schema/mvc"
   xmlns:util="http://www.springframework.org/schema/util"
   xmlns:jpa="http://www.springframework.org/schema/data/jpa"
   xsi:schemaLocation="
   http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
   http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
   http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd
   http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd
   http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd
   http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd
   http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd
   http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
   http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd">
   <!-- conf/spring-mybatis.xml For management MVC Configuration -->
   <bean id="sqlSessionFactory"
   class="org.mybatis.spring.SqlSessionFactoryBean">
   <property name="dataSource" ref="ds"/>
   <!--
   <property name="mapperLocations"
   value="classpath:mapping/*.xml"/> -->
   </bean>
   <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
   <property name="sqlSessionFactory"
   ref="sqlSessionFactory"/>
   <property name="basePackage"
   value="cn.tedu.store.dao"/>
   </bean>
   </beans>

   The mapperLocations property is temporarily commented out and then opened later with a map file.
3. Offline testing with JUnit:

   public class MyBatisTest {
   ClassPathXmlApplicationContext ctx;
   @Before
   public void init(){
   ctx = new ClassPathXmlApplicationContext(
   "conf/spring-db.xml",
   "conf/spring-mybatis.xml");
   }
   @Test
   public void testSqlSession(){
   SqlSessionFactory factory=
   ctx.getBean("sqlSessionFactory",
   SqlSessionFactory.class);
   SqlSession session=factory.openSession();
   System.out.println(session);
   session.close();
   }
   }

Implement User List

Data Layer

1. Data table structure:
   desc user;
   +-------------+-------------+------+-----+-------------------+-----------------------------+
   | Field | Type | Null | Key | Default | Extra |
   +-------------+-------------+------+-----+-------------------+-----------------------------+
   | id | int(11) | NO | PRI | NULL | auto_increment |
   | username | varchar(20) | YES | | NULL | |
   | password | varchar(30) | YES | | NULL | |
   | email | varchar(20) | YES | | NULL | |
   | mobile | varchar(20) | YES | | NULL | |
   | create_time | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
   +-------------+-------------+------+-----+-------------------+-----------------------------+

2. Add entity class user
   public class User implements Serializable {
   private static final long serialVersionUID = -7291170424207323214L;
   private Integer id;
   private String username;
   private String password;
   private String mobile;
   private String email;
   private Date createTime;
   public User() {
   }
   public User(Integer id, String username, String password, String mobile, String email, Date createTime) {
   super();
   this.id = id;
   this.username = username;
   this.password = password;
   this.mobile = mobile;
   this.email = email;
   this.createTime = createTime;
   }
   public Integer getId() {
   return id;
   }
   public void setId(Integer 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;
   }
   public String getMobile() {
   return mobile;
   }
   public void setMobile(String mobile) {
   this.mobile = mobile;
   }
   public String getEmail() {
   return email;
   }
   public void setEmail(String email) {
   this.email = email;
   }
   public Date getCreateTime() {
   return createTime;
   }
   public void setCreateTime(Date createTime) {
   this.createTime = createTime;
   }
   @Override
   public String toString() {
   return "User [id=" + id + ", username=" + username + ", password=" + password + ", mobile=" + mobile
   + ", email=" + email + ", createTime=" + createTime + "]";
   }
   @Override
   public int hashCode() {
   final int prime = 31;
   int result = 1;
   result = prime * result + ((id == null) ? 0 : id.hashCode());
   return result;
   }
   @Override
   public boolean equals(Object obj) {
   if (this == obj)
   return true;
   if (obj == null)
   return false;
   if (getClass() != obj.getClass())
   return false;
   User other = (User) obj;
   if (id == null) {
   if (other.id != null)
   return false;
   } else if (!id.equals(other.id))
   return false;
   return true;
   }
   }

3. Declare channel interface

   public interface UserDao {
   /**
   * Query all user information
   * @return User Information List
   */
   List<User> findAllUsers();
   }

4. Add mapping profile mapping / userMapper.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="cn.tedu.store.dao.UserDao">
   <!-- mapping/userMapper.xml Mapping File -->
   <!--
   result: Result
   parameter: parameter
   type: type
   resultType: Type of return result element used to declare methods
   parameterType: Type of parameter, used when the method has only one parameter!
   If more parameters are recommended @Param Annotation Label
   -->
   <select id="findAllUsers"
   resultType="cn.tedu.store.bean.User">
   select
   id,
   username,
   password,
   mobile,
   email,
   create_time as createTime
   from
   user
   </select>
   </mapper>

5. Update db.properties
   url=jdbc:mysql://localhost:3306/tedustore

6. Update spring-mybatis.xml

   <property name="mapperLocations"
   value="classpath:mapping/*.xml"/>

7. Offline Testing with JUnit

   public class UserDaoTest {
   ClassPathXmlApplicationContext ctx;
   UserDao dao;
   @Before //Method to execute before all test cases
   public void init(){
   ctx = new ClassPathXmlApplicationContext(
   "conf/spring-db.xml",
   "conf/spring-mybatis.xml");
   dao = ctx.getBean("userDao",UserDao.class);
   }
   @After //Execute destory method after all test cases are executed
   public void destory(){
   ctx.close();
   }
   @Test
   public void testFindAllUsers(){
   List<User> list=dao.findAllUsers();
   for (User user : list) {
   System.out.println(user);
   }
   }
   }

Author: Darren