大数据正式27

悠悠 2022-06-03 04:38 126阅读 0赞

# 大数据正式27 #

### Spring ###

*  先来张图简单看一下
    
     *  ![oQySJMC.png][]
 *  spring框架的特点
    
    1.  轻量级（减少侵入性、对容器没有依赖性、无须修改代码）
    2.  整合其他主流框架
 *  Spring的IOC
    
     *  旧版
        
        #  #
        
            Person p=new Person();
     *  新版
        
        #  #
        
            Person p=Spring容器.get***();
     *  通过Spring容器来管理对象更加简单，不用关心对象的创建对象----解耦
     *  Inversion of Control
     *  控制反转
     *  IOC创建对象
        
        1.  导jar包
            
             *  ![e1PTDOr.png][]
        2.  创建对象类
            
            #  #
            
                package com.peng.pojo;
                
                public class Person {
                    private String name;
                    private Integer age;
                    private Person() {
                        super();
                    }
                    private Person(String name, Integer age) {
                        super();
                        this.name = name;
                        this.age = age;
                    }
                    public String getName() {
                        return name;
                    }
                    public void setName(String name) {
                        this.name = name;
                    }
                    public Integer getAge() {
                        return age;
                    }
                    public void setAge(Integer age) {
                        this.age = age;
                    }
                    @Override
                    public String toString() {
                        return  name+":"+age;
                    }
                }
        3.  编辑xml配置文件
            
            #  #
            
                <?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:p="http://www.springframework.org/schema/p"
                    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
                    <bean id="person" class="com.peng.pojo.Person"></bean>
                </beans>
        4.  创建Spring容器
            
            #  #
            
                //创建Spring容器
                ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");//相对于src目录下
        5.  通过容器创建对象，调用对象的方法
            
            #  #
            
                //通过容器获取对象
                Person p=(Person)ac.getBean("person");
                p.setAge(1);
                p.setName("aaa");
                
                System.out.println(p);
     *  简单图示
        
         *  ![Zrlq0Lx.png][]
     *  注：项目中包名相关：entitye,domain,pojo,beans----实体类
 *  Spring配置文件的创建方式
    
    1.  通过约束文件配置
        
        1.  需要先导入约束文件【提前写好的约束文件】
        2.  过程
            
             *  ![ByXv028.png][]
             *  ![TAEg2cq.png][]
             *  ![FReNhVd.png][]
    2.  模板代码【把重复的代码作为模板放入特定的位置，通过快捷方式获取】
        
        1.  配置好相应的代码----通过快捷键快速导入
        2.  过程
            
             *  ![TCS0Gbv.png][]
             *  ![9NIci2H.png][]
             *  用的时候springsimple(alt+/快捷键)
    3.  复制已有配置文件
        
         *  ![8dNbJpD.png][]
 *  获取对象的方法
    
    1.  id方式【原理：】
        
         *  任何地方都可以
    2.  class方式【原理：】
        
         *  单个对象可以，重复类型的话----报错（found n：n1,n2...）
 *  标签纸alias
    
    #  #
    
        <alias name="和id一致" alias=""/> //此标签
 *  Spring创建对象的方式
    
     *  之前
        
         *  构造方法
         *  静态获取方法获取对象（eg：单例模式）
         *  成员函数方法获取对象
     *  现在
        
        1.  构造方法---要求类必须有无参构造方法
        2.  静态工厂【id class factory-merthod】
            
            #  #
            
                package com.peng.factory;
                
                import java.util.Date;
                
                public class CalanderFactory {
                    private static Date c = new Date();
                
                    public static Date getCalander() {
                        return c;
                    }
                }
            
            #  #
            
                @Test
                public void test2() {
                    //获取容器
                    ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");
                    //获取数据
                    System.out.println(ac.getBean("date"));
                }
            
            #  #
            
                <bean id="date" class="com.peng.factory.CalanderFactory"
                        factory-method="getCalander"></bean>
        3.  实例工厂（动态工厂）【id(工厂的id) factory-bean factory-method】
            
            #  #
            
                package com.peng.factory;
                
                import java.util.Date;
                
                public class CalanderFactory {
                    private Date c = new Date();
                
                    public Date getCalander() {
                        return c;
                    }
                }
            
            #  #
            
                @Test
                public void test2() {
                    //获取容器
                    ApplicationContext ac=new ClassPathXmlApplicationContext("applicationContext.xml");
                    //获取数据
                    System.out.println(ac.getBean("date"));
                }
            
            #  #
            
                <bean id="CalanderFactory" class="com.peng.factory.CalanderFactory"></bean>
                
                <bean id="date" factory-bean="CalanderFactory" factory-method="getCalander"></bean>
        4.  Spring工厂【实现FactoryBean接口】
 *  bean的scope属性
    
     *  默认是单例【饿汉式的创建方式】
     *  可以通过该属性来决定对象的创建是单例还是多例
        
         *  创建对象的时机
            
             *  单例--饿汉式
             *  多例--懒汉式
     *  singleton单例【获取容器的时候就创建出来了】
     *  prototype多例【获取容器时候还没有创建--获取具体实例的时候才创建出来对象】
     *  request
     *  session
     *  例
        
        #  #
        
            <bean scope=""></bean>
 *  Lazy-init懒加载【配合单例来使用：单例+懒加载】
    
     *  default（取决于 default-lazy-init=""）
        
        #  #
        
            <?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:p="http://www.springframework.org/schema/p"
                xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"
                default-lazy-init="">
            
                    <bean lazy-init=""></bean>
            
            </beans>
     *  true
     *  false
     *  例
        
        #  #
        
            <bean lazy-init=""></bean>
 *  spring容器管理对象的生命周期
    
     *  spring管理的对象：单例对象
     *  对象创建
     *  对象初始化【init-method】
     *  对象销毁【init-method】
     *  例
        
        #  #
        
            <bean id="person" class="com.peng.pojo.Person" init-method=""
            destroy-method=""></bean>

### DI（Dependency Injection） ###

*  依赖注入（属性注入）
    
     *  set方式：必须要有setter方法
        
         *  property属性-----具体的属性名
         *  ref对象-----bean的id
        
        #  #
        
            package com.peng.pojo;
            
            public class Person {
                private String name;
                private Integer age;
                private Person() {
                    super();
                }
                private Person(String name, Integer age) {
                    super();
                    this.name = name;
                    this.age = age;
                }
                public String getName() {
                    return name;
                }
                public void setName(String name) {
                    this.name = name;
                }
                public Integer getAge() {
                    return age;
                }
                public void setAge(Integer age) {
                    this.age = age;
                }
                @Override
                public String toString() {
                    return  name+":"+age;
                }
            
            }
        
        #  #
        
            package com.peng.pojo;
            
            import java.util.List;
            import java.util.Map;
            import java.util.Properties;
            import java.util.Set;
            
            public class Info {
                private String name;
                private Integer age;
                private List<String> list;
                private Properties prop;
                private Map<String, String> map;
                private Set<String> set;
                private Person person;
            
                // 无参构造
                private Info() {
                    super();
                }
            
                // 含参构造
                private Info(String name, Integer age, List<String> list, Properties prop,
                        Map<String, String> map, Set<String> set, Person person) {
                    super();
                    this.name = name;
                    this.age = age;
                    this.list = list;
                    this.prop = prop;
                    this.map = map;
                    this.set = set;
                    this.person = person;
                }
            
                // setter/getter方法
            
                public String getName() {
                    return name;
                }
            
                public void setName(String name) {
                    this.name = name;
                }
            
                public Integer getAge() {
                    return age;
                }
            
                public void setAge(Integer age) {
                    this.age = age;
                }
            
                public List<String> getList() {
                    return list;
                }
            
                public void setList(List<String> list) {
                    this.list = list;
                }
            
                public Properties getProp() {
                    return prop;
                }
            
                public void setProp(Properties prop) {
                    this.prop = prop;
                }
            
                public Map<String, String> getMap() {
                    return map;
                }
            
                public void setMap(Map<String, String> map) {
                    this.map = map;
                }
            
                public Set<String> getSet() {
                    return set;
                }
            
                public void setSet(Set<String> set) {
                    this.set = set;
                }
            
                public Person getPerson() {
                    return person;
                }
            
                public void setPerson(Person person) {
                    this.person = person;
                }
            
            }
        
        #  #
        
            <?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:p="http://www.springframework.org/schema/p"
                xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
            
                <bean id="person" class="com.peng.pojo.Person">
                    <property name="name" value="人"></property>
                    <property name="age" value="28"></property>
                </bean>
            
                <bean id="info" class="com.peng.pojo.Info">
                    <property name="name" value="信息"></property>
                    <property name="age" value="11"></property>
                    <property name="list">
                        <list>
                            <value>1</value>
                            <value>2</value>
                            <value>3</value>
                            <value>3</value>
                        </list>
                    </property>
                    <property name="prop">
                        <props>
                            <prop key="a">a</prop>
                            <prop key="b">b</prop>
                        </props>
                    </property>
                    <property name="map">
                        <map>
                            <entry key="A" value="A"></entry>
                            <entry key="B" value="B"></entry>
                        </map>
                    </property>
                    <property name="set">
                        <set>
                            <value>11</value>
                            <value>22</value>
                        </set>
                    </property>
                    <property name="person" ref="person"></property>
                </bean>
            
            </beans>
        
        #  #
        
            @Test
            public void test3() {
                // 获取容器
                ApplicationContext ac = new ClassPathXmlApplicationContext(
                        "applicationContext.xml");
                // 获取数据
                System.out.println(((Info) ac.getBean("info")).getName());
                System.out.println(((Info) ac.getBean("info")).getAge());
                System.out.println(((Info) ac.getBean("info")).getList());
                System.out.println(((Info) ac.getBean("info")).getMap());
                System.out.println(((Info) ac.getBean("info")).getProp());
                System.out.println(((Info) ac.getBean("info")).getSet());
                System.out.println(((Info) ac.getBean("info")).getPerson());
            }
     *  构造方法：必须有相应的构造方法【注意：注入几个属性--提供相同数量的属性的构造函数】【index：从零开始】
        
        #  #
        
            // 含参构造
            private Info(String name, Integer age, List<String> list, Properties prop,
                    Map<String, String> map, Set<String> set, Person person) {
                super();
                this.name = name;
                this.age = age;
                this.list = list;
                this.prop = prop;
                this.map = map;
                this.set = set;
                this.person = person;
            }
        
        #  #
        
            <constructor-arg  name="" value=""></constructor-arg>
            <constructor-arg  name="" ref=""></constructor-arg>
        
        #  #
        
            <constructor-arg index="" value=""></constructor-arg>
            <constructor-arg index="" ref=""></constructor-arg>

### 经典三层架构spring版--工厂用Spring代替 ###

*  ![mznYDz0.png][]
 *  dao
    
     *  PersonDao
        
        #  #
        
            package com.peng.dao;
            
            import com.peng.pojo.Person;
            
            public interface PersonDao {
                void savePerson(Person p);
            }
     *  PersonDaoImpl
        
        #  #
        
            package com.peng.dao;
            
            import com.peng.pojo.Person;
            
            public class PersonDaoImpl implements PersonDao {
            
                @Override
                public void savePerson(Person p) {
                    System.out.println("保存了：" + p);
                }
            
            }
 *  pojo
    
     *  Person
        
        #  #
        
            package com.peng.pojo;
            
            public class Person {
                private String name;
                private Integer age;
            
                private Person() {
                    super();
                }
            
                private Person(String name, Integer age) {
                    super();
                    this.name = name;
                    this.age = age;
                }
            
                public String getName() {
                    return name;
                }
            
                public void setName(String name) {
                    this.name = name;
                }
            
                public Integer getAge() {
                    return age;
                }
            
                public void setAge(Integer age) {
                    this.age = age;
                }
            
            }
 *  service
    
     *  PersonService
        
        #  #
        
            package com.peng.service;
            
            import com.peng.pojo.Person;
            
            public interface PersonService {
                void savePerson(Person p);
            }
     *  PersonServiceImpl
        
        #  #
        
            package com.peng.service;
            
            import com.peng.dao.PersonDao;
            import com.peng.pojo.Person;
            
            public class PersonServiceImpl implements PersonService {
                private PersonDao dao;
            
                public PersonDao getDao() {
                    return dao;
                }
            
                public void setDao(PersonDao dao) {
                    this.dao = dao;
                }
            
                @Override
                public void savePerson(Person p) {
                    if (null != dao) {
                        dao.savePerson(p);
                    }
                }
            
            }
 *  test
    
     *  Test
        
        #  #
        
            package com.peng.test;
            
            import org.springframework.context.ApplicationContext;
            import org.springframework.context.support.ClassPathXmlApplicationContext;
            
            import com.peng.pojo.Person;
            import com.peng.web.PersonServlet;
            
            public class Test {
                @org.junit.Test
                public void trest1() {
                    ApplicationContext ac = new ClassPathXmlApplicationContext(
                            "applicationContext.xml");
                    Person person = (Person) ac.getBean("person");
                    PersonServlet servlet = (PersonServlet) ac.getBean("servlet");
                    servlet.doSomething(person);
                }
            }
 *  web
    
     *  PersonServlet
        
        #  #
        
            package com.peng.web;
            
            import com.peng.pojo.Person;
            import com.peng.service.PersonService;
            
            public class PersonServlet {
                private PersonService service;
            
                public PersonService getService() {
                    return service;
                }
            
                public void setService(PersonService service) {
                    this.service = service;
                }
            
                public void doSomething(Person p) {
                    service.savePerson(p);
                }
            }
 *  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:p="http://www.springframework.org/schema/p"
            xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
            
            <bean id="person" class="com.peng.pojo.Person">
                <property name="name" value="zhangsan"></property>
                <property name="age" value="11"></property>
            </bean>
            
            <bean id="dao" class="com.peng.dao.PersonDaoImpl"></bean>
            
            <bean id="service" class="com.peng.service.PersonServiceImpl">
                <property name="dao" ref="dao"></property>
            </bean>
            
            <bean id="servlet" class="com.peng.web.PersonServlet">
                <property name="service" ref="service"></property>
            </bean>
        </beans>

### Xml约束：规范xml的具体规则 ###

1. Scheme
    2. DTD

### 简单回顾流程 ###

*  ![oQySJMC.png][]

### 补充 ###

*  ![JBrMeiT.jpg][]

[oQySJMC.png]: https://i.imgur.com/oQySJMC.png
[e1PTDOr.png]: https://i.imgur.com/e1PTDOr.png
[Zrlq0Lx.png]: https://i.imgur.com/Zrlq0Lx.png
[ByXv028.png]: https://i.imgur.com/ByXv028.png
[TAEg2cq.png]: https://i.imgur.com/TAEg2cq.png
[FReNhVd.png]: https://i.imgur.com/FReNhVd.png
[TCS0Gbv.png]: https://i.imgur.com/TCS0Gbv.png
[9NIci2H.png]: https://i.imgur.com/9NIci2H.png
[8dNbJpD.png]: https://i.imgur.com/8dNbJpD.png
[mznYDz0.png]: https://i.imgur.com/mznYDz0.png
[JBrMeiT.jpg]: https://i.imgur.com/JBrMeiT.jpg