Spring Recipes 1

最新推荐文章于 2024-06-23 23:49:21 发布

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最新推荐文章于 2024-06-23 23:49:21 发布

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原文链接：https://my.oschina.net/wtm/blog/306959

本文介绍如何使用Spring IoC容器实例化并配置SequenceGenerator Bean，演示了使用不同方式进行配置的方法，包括通过setter注入、构造器注入以及pschema简化配置。

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1.实例化Spring IoC容器：

Spring Ioc容器有两种类型： BeanFactory和ApplicationContext

ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");

从IoC容器中得到Bean

SequenceGenerator generator = (SequenceGenerator) context.getBean("sequenceGenerator");

2.配置Spring IoC容器中的Bean（简单属性：

完整事例代码（包括SequenceGenerator.java + beans.xml + Main.java）,有多个beans.xml任选其一，不同的beans.xml说明了不同的配置方式。

SequenceGenerator.java

package com.apress.springrecipes.sequence;


public class SequenceGenerator {

    private String prefix;
    
    private String suffix;
    
    private int initial;
    
    private int counter;
    
    public SequenceGenerator() {}

    public SequenceGenerator(String prefix, String suffix, int initial) {
        super();
        this.prefix = prefix;
        this.suffix = suffix;
        this.initial = initial;
    }

    public void setPrefix(String prefix) {
        this.prefix = prefix;
    }

    public void setSuffix(String suffix) {
        this.suffix = suffix;
    }

    public void setInitial(int initial) {
        this.initial = initial;
    }

    public synchronized String getSequence() {
        StringBuffer buffer = new StringBuffer();
        buffer.append(prefix);
        buffer.append(initial + counter++);
        buffer.append(suffix);
        return buffer.toString();
    }
}

beans.xml(使用set方法)

<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
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id="sequenceGenerator" class=" com.apress.springrecipes.sequence.SequenceGenerator">
        <property name="prefix">
            <value>30</value>
        </property>
        <property name="suffix">
            <value>A</value>
        </property>
        <property name="initial">
            <value>100000</value>
        </property>
    </bean>
</beans>

beans.xml(使用set方法,简写)

<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
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id="sequenceGenerator" class=" com.apress.springrecipes.sequence.SequenceGenerator">
        <property name="prefix" value="30"/>
        <property name="suffix" value="A"/>
        <property name="initial" value="100000"/>
    </bean>
</beans>

beans.xml(使用构造器方法)

<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
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id="sequenceGenerator" class=" com.apress.springrecipes.sequence.SequenceGenerator">
        <constructor-arg>
            <value>30</value>
        </constructor-arg>
        <constructor-arg>
            <value>A</value>
        </constructor-arg>
        <constructor-arg>
            <value>100000</value>
        </constructor-arg>
    </bean>
</beans>

beans.xml(使用构造器方法，简写)

<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
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <bean id="sequenceGenerator" class=" com.apress.springrecipes.sequence.SequenceGenerator">
        <constructor-arg value="30"/>
        <constructor-arg value="A"/>
        <constructor-arg value="100000"/>
    </bean>
</beans>

beans.xml(p schema)，注意：xmlns:p="http://www.springframework.org/schema/p"

<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="sequenceGenerator" class=" com.apress.springrecipes.sequence.SequenceGenerator"
        p:prefix="30" p:suffix="A" p:initial="100000"/>
</beans>

Main.java方法

package com.apress.springrecipes.sequence;

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

public class Main {

    public static void main(String[] args) {
        ApplicationContext context = 
            new ClassPathXmlApplicationContext("beans.xml");

        SequenceGenerator generator =
            (SequenceGenerator) context.getBean("sequenceGenerator");

        System.out.println(generator.getSequence());
        System.out.println(generator.getSequence());
    }
}

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