Spring框架学习之第8节

<bean id=”foo” class=”…Foo”>

         <property name=”属性”>

         <!—第一方法引用-->

         <ref bean=”bean对象名”>

         <!—内部bean—>

         <bean>

         <property></property>

         </bean>

         </property>

</bean>

④集成配置

public class Student

public class Graduate extends Student

在beans.xml文件中配置

思考：目前我们都是通过set的方式给bean注入值的，spring还提供了其他的方式注入值，通过构造函数注入值

•  通过构造函数注入值

beans.xml文件关键代码

<!-- 配置一个雇员对象 -->

<bean id="employee" class="com.litao.constructor.Employee">

<!-- 通过构造函数来注入属性值 index代表第几个参数，type是类型 -->

<constructor-arg index="0" type="java.lang.String" value="大明"/>

<constructor-arg index="1" type="int" value="23"/>

</bean>

set注入的缺点是无法清晰表达哪些属性是必须的，哪些是可选的，构造注入的优势是通过构造强制依赖关系，不可能实例化不完全的或无法使用的bean。

•  自动装配bean的属性值 

 

（1）   byName的用法

<!-- 配置一个master对象 -->

<bean id="master" class="com.litao.autowire.Master" autowire="byName">

<property name="name">

<value>顺平</value>

</property>

<!--

/* 传统的方法 */

<property name="dog" ref="dog" />

-->

</bean>

<!-- 配置dog对象 -->

<bean id="dog" class="com.litao.autowire.Dog">

<property name="name" value="小黄" />

<property name="age" value="3" />

</bean>

原理图：

（1）       byType

寻找和属性类型相同的bean,找不到,装不上,找到多个抛异常

（2）       constructor：autowire="constructor"

说明：

查找和bean的构造参数一致的一个或多个bean，若找不到或找到多个，抛异常。按照参数的类型装配。

（3）       autodetect：autowire="autodetect"

说明：(3)和(2)之间选一个方式。不确定

       性的处理与(3)和(2)一致。

（4）       defualt

这个需要在<beans defualt-autorwire=“指定” />

当你在<beans>指定了default-autowire后，所有的bean的默认的autowire就是指定的装配方法

如果没有在<beans defualt-autorwire=“指定” />，没有default-autowire=”指定”，则默认是default-autowire=”no”.

（5）       no：不自动装配

使用spring的特殊bean,完成分散配置

beans.xml

说明：当通过context:property-placeholder引入多个属性文件的时候使用逗号间隔

<!-- 引入我们的db.properties文件 -->

<context:property-placeholder location="classpath:com/litao/dispatch/db.properties,classpath:com/litao/dispatch/db2.properties"/>

<!-- 配置一个DButil对象 -->

<bean id="dbutil" class="com.litao.dispatch.DBUtil">

<property name="name" value="${name}" />

<property name="drivername" value="${drivername}" />

<property name="url" value="${url}" />

<property name="pwd" value="${pwd}" />

</bean>

<!-- 配置一个DButil2对象 -->

<bean id="dbutil2" class="com.litao.dispatch.DBUtil">

<property name="name" value="${db2.name}" />

<property name="drivername" value="${db2.drivername}" />

<property name="url" value="${db2.url}" />

<property name="pwd" value="${db2.pwd}" />

</bean>

db.properties

name=scott

drivername=oracle:jdbc:driver:OracleDriver

url=jdbc:oracle:thin:@127.0.0.1:1521:hsp

pwd=tiger

#key=value

项目结构：

/******************************com.litao.autowire包***************************************************/

com.litao.autowire.App1.java

package com.litao.autowire;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
 
public class App1 {
 
    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/autowire/beans.xml");
        //通过容器获取主人
        Master master = (Master) ac.getBean("master");
        System.out.println(master.getName()+" "+master.getDog().getName());
        
    }
 
}

com.litao.autowire.Dog.java

package com.litao.autowire;

import javax.annotation.Resource;


public class Dog {
	
	private String name;
	private int age;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}

}

com.litao.autowire.Master.java

package com.litao.autowire;

public class Master {
	
	private String name;
	private Dog dog;
	
	public Master(Dog dog){
		System.out.println("Master(Dog dog)构造函数被调用");
		this.dog = dog;
	}
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public Dog getDog() {
		return dog;
	}
	public void setDog(Dog dog) {
		this.dog = dog;
	}

}

com.litao.autowire.beans.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:tx="http://www.springframework.org/schema/tx"
		xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
				http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd"
				 default-autowire="no"
				>        


<!-- 配置一个master对象 -->
<bean id="master" class="com.litao.autowire.Master">
<property name="name">
<value>顺平</value>
</property>
<!-- 
/* 传统的方法 */
<property name="dog" ref="dog" />
-->
</bean>
<!-- 配置dog对象 -->
<bean id="dog11" class="com.litao.autowire.Dog">
<property name="name" value="小黄" />
<property name="age" value="3" />
</bean>

</beans>

/******************************com.litao.collection包***************************************************/

App1.java

package com.litao.collection;
 
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;
import java.util.Map.Entry;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
 
public class App1 {
 
    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/collection/beans.xml");
 
        Department department = (Department)ac.getBean("department");
        System.out.println(department.getName());
        for (String emName : department.getEmpName()) {
            System.out.println(emName);
        }
         
        System.out.println("************通过list集合取出数据**************");
        for(Employee e: department.getEmpList()){
             
            System.out.println("name=" + e.getName() + " " + e.getId());
             
        }
         
        //set取得时候不能保证顺序，list取时可以保证顺序
        System.out.println("************通过set集合取出数据**************");
        for(Employee e: department.getEmpsets()){
             
            System.out.println("name=" + e.getName());
             
        }
        System.out.println("************通过map集合取出数据**************");
        //1.用迭代器
        Map<String,Employee> empmaps = department.getEmpMaps();
         
        Iterator it = empmaps.keySet().iterator();
         
        while (it.hasNext()) {
            String key = (String)it.next();
            //System.out.println(key);
            Employee emp = empmaps.get(key);
            System.out.println("key="+key+" "+emp.getName());
        }
         
        //2.最简洁的方法
        for(Entry<String,Employee> entry1:department.getEmpMaps().entrySet()){
            System.out.println(entry1.getKey() + " " + entry1.getValue().getName());
             
        }
        
        System.out.println("**************通过Properties取出数据**************");
         Properties pp = department.getPp();
         //System.out.println(pp.getProperty("pp1").toString());
         for(Entry<Object,Object> entry:pp.entrySet()){
        	 System.out.println(entry.getKey().toString()+" "+ entry.getValue().toString());	 
         }
         System.out.println("**************通过Enumeration取出数据**************");

         Enumeration en = pp.keys();
         while (en.hasMoreElements()) {
        	 //Entry<Object,Object> element = (Entry<Object,Object>) en.nextElement();
			//System.out.println(element.getKey()+ " " +element.getValue());
			
        	 String key = (String)en.nextElement();
        	 
			System.out.println(key+ " " + pp.getProperty(key));
		}
         
    }
 
}

Department.java

package com.litao.collection;
 
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
 
public class Department {
 
    private String name;
    private String[] empName;
    private List<Employee> empList;
    private Set<Employee> empsets;
    private Map<String,Employee> empMaps;
    private Properties pp;//Properties的配置使用
    
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String[] getEmpName() {
        return empName;
    }
    public void setEmpName(String[] empName) {
        this.empName = empName;
    }
     
    public List<Employee> getEmpList() {
        return empList;
    }
    public void setEmpList(List<Employee> empList) {
        this.empList = empList;
    }
    public Set<Employee> getEmpsets() {
        return empsets;
    }
    public void setEmpsets(Set<Employee> empsets) {
        this.empsets = empsets;
    }
    public Map<String, Employee> getEmpMaps() {
        return empMaps;
    }
    public void setEmpMaps(Map<String, Employee> empMaps) {
        this.empMaps = empMaps;
    }
	public Properties getPp() {
		return pp;
	}
	public void setPp(Properties pp) {
		this.pp = pp;
	}
     
     
}

Employee.java

package com.litao.collection;
 
public class Employee {
     
    private String name;
    private int id;
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public int getId() {
        return id;
    }
 
    public void setId(int id) {
        this.id = id;
    }
 
}

beans.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:tx="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="
            http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
 
<bean id="department" class="com.litao.collection.Department">
<property name="name" value="财务部" />
<!-- 给数组注入值 -->
<property name="empName">
<list>
    <value>小明</value>
    <value>小明小明</value>
    <value>小明小明小明小明</value>
</list>
</property>
<!-- 给list注入值 list中可以有相同的对象 -->
<property name="empList">
    <list>
        <ref bean="emp1"/>
        <ref bean="emp2"/>
        <ref bean="emp2"/>
        <ref bean="emp2"/>
        <ref bean="emp2"/>
    </list>
</property>
<!-- 给set注入值 set中不能有相同的对象 -->
<property name="empsets">
    <set>
        <ref bean="emp1"/>
        <ref bean="emp2"/>
        <ref bean="emp2"/>
        <ref bean="emp2"/>
        <ref bean="emp2"/>
        <ref bean="emp2"/>
    </set>
</property>
<!-- 给map注入值 map中也不能有相同的对象，后面的会把前面的覆盖，map只要key一样就可以装配value对应的bean -->
<property name="empMaps">
    <map>
        <entry key="1" value-ref="emp1"></entry>
        <entry key="2" value-ref="emp2"></entry>
        <entry key="2" value-ref="emp2"></entry>
    </map>
</property>
<!-- 给属性集合配置 -->
<property name="pp">
	<props>
		<prop key="pp1">abcd</prop>
		<prop key="pp2">hello</prop>		
	</props>
</property>
</bean>
<bean id="emp1" class="com.litao.collection.Employee">
<property name="name" value="北京" />
<property name="id" value="1" />
</bean>
<bean id="emp2" class="com.litao.collection.Employee">
<property name="name" value="天津" />
<property name="id" value="2" />
</bean>
</beans>

/******************************com.litao.constructor包************************************************/

App1.java

package com.litao.constructor;

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

public class App1 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
        ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/constructor/beans.xml");

        Employee ee = (Employee)ac.getBean("employee");
        System.out.println(ee.getName());
	}

}

Employee.java

package com.litao.constructor;

public class Employee {
	
	private String name;
	private int age;
	
	
	public Employee() {
	}
	
	public Employee(String name, int age) {
		System.out.println("Employee(String name, int age)构造函数被调用");
		this.name = name;
		this.age = age;
	}
	
	public Employee(String name) {
		System.out.println("Employee(String name)构造函数被调用");
		this.name = name;
	}
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	
	

}

beans.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:tx="http://www.springframework.org/schema/tx"
		xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
				http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
 
<!-- 配置一个雇员对象 -->
<bean id="employee" class="com.litao.constructor.Employee">
<!-- 通过构造函数来注入属性值 index代表第几个参数，type是类型 -->
<constructor-arg index="0" type="java.lang.String" value="大明"/>
<constructor-arg index="1" type="int" value="23"/>
</bean>
</beans>

　　

/******************************com.litao.dispatch包************************************************/

App1.java

package com.litao.dispatch;

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

public class App1 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
        ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/dispatch/beans.xml");

        DBUtil dbUtil = (DBUtil)ac.getBean("dbutil2");
        System.out.println(dbUtil.getDrivername()+" "+ dbUtil.getPwd());
	
	}

}

DBUtil.java

package com.litao.dispatch;

public class DBUtil {
	
	private String drivername;
	private String url;
	private String name;
	private String pwd;
	
	public String getDrivername() {
		return drivername;
	}
	public void setDrivername(String drivername) {
		this.drivername = drivername;
	}
	public String getUrl() {
		return url;
	}
	public void setUrl(String url) {
		this.url = url;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getPwd() {
		return pwd;
	}
	public void setPwd(String pwd) {
		this.pwd = pwd;
	}

}

beans.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:tx="http://www.springframework.org/schema/tx"
		xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
				http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
				http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">        

<!-- 引入我们的db.properties文件 -->
<context:property-placeholder location="classpath:com/litao/dispatch/db.properties,classpath:com/litao/dispatch/db2.properties"/>
<!-- 配置一个DButil对象 -->
<bean id="dbutil" class="com.litao.dispatch.DBUtil">
<property name="name" value="${name}" />
<property name="drivername" value="${drivername}" />
<property name="url" value="${url}" />
<property name="pwd" value="${pwd}" />
</bean>

<!-- 配置一个DButil2对象 -->
<bean id="dbutil2" class="com.litao.dispatch.DBUtil">
<property name="name" value="${db2.name}" />
<property name="drivername" value="${db2.drivername}" />
<property name="url" value="${db2.url}" />
<property name="pwd" value="${db2.pwd}" />
</bean>
</beans>

db.properties

name=scott
drivername=oracle:jdbc:driver:OracleDriver
url=jdbc:oracle:thin:@127.0.0.1:1521:hsp
pwd=tiger
#key=value

db.properties2

db2.name=scott3
db2.drivername=oracle:jdbc:driver:OracleDriver3
db2.url=jdbc:oracle:thin:@127.0.0.1:1521:hsp3
db2.pwd=tiger3

#key=value

/******************************com.litao.inherit包************************************************/

App1.java

package com.litao.inherit;

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

public class App1 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub

		   ApplicationContext ac = new ClassPathXmlApplicationContext("com/litao/inherit/beans.xml");
		   
		   Graduate graduate = (Graduate)ac.getBean("graduate");
		   System.out.println(graduate.getName() + " " + graduate.getAge() + " " + graduate.getDegree());
		   
	}

}

Graduate.java

package com.litao.inherit;

public class Graduate extends Student {
	
	private String degree;

	public String getDegree() {
		return degree;
	}

	public void setDegree(String degree) {
		this.degree = degree;
	}
	

}

Student.java

package com.litao.inherit;

public class Student {
	
	protected String name;
	protected String age;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getAge() {
		return age;
	}
	public void setAge(String age) {
		this.age = age;
	}

}

beans.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:tx="http://www.springframework.org/schema/tx"
        xsi:schemaLocation="
            http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
            http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
            http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
 
<!-- 配置一个学生对象 -->
<bean id="student" class="com.litao.inherit.Student">
	<property name="name" value=" 李涛" />
	<property name="age" value="30" />
</bean>
<!-- 配置一个Graduate对象 -->
<bean id="graduate" parent="student" class="com.litao.inherit.Graduate">
	<!-- 如果自己配置属性name,age,则会替换从父对象集成的数据 -->
	<property name="name" value="小明" />
	<property name="degree" value="学士" />
</bean>
</beans>