简单实现Spring IOC （单例模式）（解析XML方式）

基于XML方式的依赖注入，主要是基于XML的解析，类的反射机制 

主要思路：

           1、解析xml文件

           2、获取xml文件所有的节点内容

           3、根据类路径反射类

           4、注入属性信息

项目基本框架：

1、首先创建普通maven项目，导入dom4j、Spring context等的依赖

pom.xml(我直接复制的，所以spring的基本依赖基本都有，可以自己选择性导入)

  4.0.0

  com.spring.xml
  ioc
  1.0-SNAPSHOT

  ioc
  
  http://www.example.com

  
    UTF-8
    1.7
    1.7
    
    4.3.7.RELEASE
  

  

    
      junit
      junit
      4.11
      test
    

    
      dom4j
      dom4j
      1.6.1
    

    
    
      org.springframework
      spring-aop
      ${org.springframework.version}
    
    
      org.springframework
      spring-aspects
      ${org.springframework.version}
    
    
      org.springframework
      spring-beans
      ${org.springframework.version}
    
    
      org.springframework
      spring-context
      ${org.springframework.version}
    
    
      org.springframework
      spring-context-support
      ${org.springframework.version}
    
    
      org.springframework
      spring-core
      ${org.springframework.version}
    
    
      org.springframework
      spring-expression
      ${org.springframework.version}
    
    
      org.springframework
      spring-instrument
      ${org.springframework.version}
    
    
      org.springframework
      spring-instrument-tomcat
      ${org.springframework.version}
    
    
      org.springframework
      spring-jdbc
      ${org.springframework.version}
    
    
      org.springframework
      spring-jms
      ${org.springframework.version}
    
    
      org.springframework
      spring-messaging
      ${org.springframework.version}
    
    
      org.springframework
      spring-orm
      ${org.springframework.version}
    
    
      org.springframework
      spring-oxm
      ${org.springframework.version}
    
    
      org.springframework
      spring-test
      ${org.springframework.version}
    
    
      org.springframework
      spring-tx
      ${org.springframework.version}
    
    
      org.springframework
      spring-web
      ${org.springframework.version}
    
    
      org.springframework
      spring-webmvc
      ${org.springframework.version}
    
    
      org.springframework
      spring-webmvc-portlet
      ${org.springframework.version}
    
    
      org.springframework
      spring-websocket
      ${org.springframework.version}
    
    
  

  
    
      
        
          maven-clean-plugin
          3.0.0
        
        
        
          maven-resources-plugin
          3.0.2
        
        
          maven-compiler-plugin
          3.7.0
        
        
          maven-surefire-plugin
          2.20.1
        
        
          maven-jar-plugin
          3.0.2
        
        
          maven-install-plugin
          2.5.2
        
        
          maven-deploy-plugin
          2.8.2
        
      
    
  

2、创建bean

package com.spring.xml.bean;

public class Car {
    private String name;
    private int price;

    public String getName() {
        return name;
    }

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

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Car{" +
                "name='" + name + '\'' +
                ", price=" + price +
                '}';
    }
}

 3、创建applicationContext.xml

4、创建类XmlApplicationContext

package com.spring.xml.utils;

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import org.springframework.util.ResourceUtils;

import java.io.File;
import java.io.FileNotFoundException;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.*;

/**
 * 1、解析xml文件
 * 2、获取xml文件所有的节点内容
 * 3、根据类路径反射类
 * 4、注入属性信息
 */
public class XmlApplicationContext {
    // xml路径
    private String xmlPath;
    // 存放bean
    private Map map = null;
    // 存放从xml解析出来的类的需要注入的属性名和属性值
    private List propertyName = new ArrayList<>();
    private List