spring学习（一）（beans.xml的注值配置）

在spring 刚开始学习的时候，就只有简单的注值，在beans.xml中进行配置，将各种类交给spring来管理。这里，有几种简单的beans.xml的配置方法。

有多种bean的配置方法，大体上分为三种，一种为通过构造函数来配置，一种通过属性来配置，还有一种是通过p空间来配置。一下来简单说说这三种配置方法。

配置之前，先来几个实体类，以下的配置都是基于这几个实体类。

package com.yc.spring02;

public class Student {
    
    private String sid;
    private String name;
    private String  sex;
    
    private Address address;

    @Override
    public String toString() {
        return "Student [sid=" + sid + ", name=" + name + ", sex=" + sex + ", address=" + address + "]";
    }

    public String getSid() {
        return sid;
    }

    public void setSid(String sid) {
        this.sid = sid;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((name == null) ? 0 : name.hashCode());
        result = prime * result + ((sex == null) ? 0 : sex.hashCode());
        result = prime * result + ((sid == null) ? 0 : sid.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;
        Student other = (Student) obj;
        if (name == null) {
            if (other.name != null)
                return false;
        } else if (!name.equals(other.name))
            return false;
        if (sex == null) {
            if (other.sex != null)
                return false;
        } else if (!sex.equals(other.sex))
            return false;
        if (sid == null) {
            if (other.sid != null)
                return false;
        } else if (!sid.equals(other.sid))
            return false;
        return true;
    }

    public Student(String sid, String name, String sex) {
        super();
        this.sid = sid;
        this.name = name;
        this.sex = sex;
    }

    public Student() {
        super();
    }

    public Student(String sid, String name, String sex, Address address) {
        super();
        this.sid = sid;
        this.name = name;
        this.sex = sex;
        this.address = address;
    }
    
    public Student(Address address){
        this.address = address;
    }
    
}

Student.java

Address类：

package com.yc.spring02;

public class Address {
    private String country;
    private String city;
    
    @Override
    public String toString() {
        return "Address [country=" + country + ", city=" + city + "]";
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((city == null) ? 0 : city.hashCode());
        result = prime * result + ((country == null) ? 0 : country.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;
        Address other = (Address) obj;
        if (city == null) {
            if (other.city != null)
                return false;
        } else if (!city.equals(other.city))
            return false;
        if (country == null) {
            if (other.country != null)
                return false;
        } else if (!country.equals(other.country))
            return false;
        return true;
    }

    public Address(String country, String city) {
        super();
        this.country = country;
        this.city = city;
    }

    public Address() {
        super();
    }
    
    
    
    
}

Address

关系：Student类中有一个address属性，该属性的类型是Address

好了现在简单来讲讲bean的配置。

（一）通过构造函数来配置。

   
        <bean id="student01" class="com.yc.spring02.Student">
            <constructor-arg value="YC001">constructor-arg>
            <constructor-arg value="yc">constructor-arg>
            <constructor-arg value="男">constructor-arg>
        bean>
        
        
         <bean id="student02" class="com.yc.spring02.Student">
            <constructor-arg name = "name" value="yc">constructor-arg>
            <constructor-arg name = "sex" value="男">constructor-arg>
            <constructor-arg name = "sid" value="YC001">constructor-arg>
        bean>
        
        
         <bean id="student03" class="com.yc.spring02.Student">
            <constructor-arg index="1" value="yc">constructor-arg>
            <constructor-arg index="2" value="男">constructor-arg>
            <constructor-arg index="0" value="YC001">constructor-arg>
        bean>
    

注意：要想要构造方法配置，则在实体类中必须要有对应的构造方法。

 

（二）通过属性来配置

注意：通过属性来配置时，要有实体类中要有对应的set方法，如果没有，则配置失败

         
         <bean id="student06" class="com.yc.spring02.Student">
            <property name="sid" value="yc001">property>
             <property name="name" value="yc">property>
             <property name="sex" value="男">property>
　　　　　　　　<property name="address" ref="addr01">property>

        bean>

来个小结：关于构造方法配置和属性配置两种，可以混用，同时，还有一些骚操作，如下：

 <bean id="student07" class="com.yc.spring02.Student">
            <constructor-arg index="1" value="yc">constructor-arg>
            <constructor-arg index="2" value="男">constructor-arg>
            <constructor-arg index="0" value="YC001">constructor-arg>
            <constructor-arg index="3">
                <null/>
            constructor-arg>
         bean>
         
         

        
            <bean id="addr01" class="com.yc.spring02.Address">
                <property name="country" value="中国">property>
                <property name="city">
                                    
                    <value><衡阳>]]>value>
                property>
            bean>
            
             <bean id="student04" class="com.yc.spring02.Student">
            <constructor-arg index="1" value="yc">constructor-arg>
            <constructor-arg index="2" value="男">constructor-arg>
            <constructor-arg index="0" value="YC001">constructor-arg>
            <property name="address" ref = "addr01">property>
        bean>
        
        
         <bean id="student05" class="com.yc.spring02.Student">
             <property name="sid" value="yc001">property>
             <property name="name" value="yc">property>
             <property name="sex" value="男">property>
             <property name="address" >
                 <bean class="com.yc.spring02.Address">
                     <property name="country" value="中国">property>
                     <property name="city" value="长沙">property>
                 bean>
             property>
         bean>
        

 

（三）p命名空间的使用，p命名空间可以是配置简化，要想使用p空间，则要添加p空间的声明：xmlns:p="http://www.springframework.org/schema/p" ，放在beans标签里面，

具体p空间的使用如下：

    
         
         
         
         <bean id="student08" class="com.yc.spring02.Student" p:sid="yc002" p:name="yc" p:sex="男" p:address-ref="addr01">bean> 
         
         
         <bean id="student09" class="com.yc.spring02.Student" p:sid="yc002" p:name="yc" p:sex="男"  autowire="byName">bean> 
         
         <bean id="address" class="com.yc.spring02.Address">
                <property name="country" value="中国">property>
                <property name="city" value="常数">property>
           bean>
         
         
         
         
         
          <bean id="student12" class="com.yc.spring02.Student" p:sid="yc002" p:name="yc" p:sex="男"  autowire="default">bean> 
         
         
         
         <bean id="student13" class="com.yc.spring02.Student" p:sid="yc002" p:name="yc" p:sex="男"  autowire="constructor">bean> 
         
         
             
          
          <bean id="addr03" class="com.yc.spring02.Address" p:country="湖南" p:city="长沙" >bean>
         <bean id="addr04" class="com.yc.spring02.Address" parent="addr03" p:city="衡阳">bean>
         
         <bean id="student10" class="com.yc.spring02.Student" p:sid="yc002" p:name="yc" p:sex="男"  autowire="byName" depends-on="address">bean> 
        
        
         <bean id="student14" class="com.yc.spring02.Student" p:sid="yc002" p:name="yc" p:sex="男" p:address-ref="addr01" scope="prototype">bean> 
        
        

 

当然，在beans.xml中还可以引用另一个xml配置文件：

 
        <import resource="list.xml" />