spring学习笔记(一)-----sping的简单模拟

? ?xm+dom4j+javaReflect实现sping的一个简单模拟

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? ? Bean.xml代码

<?xml version="1.0" encoding="UTF-8"?><beans><bean id="hello" value="我的第一个Spring2.5程序!"/></bean><bean id="student" value="张三"/><property name="age" value="20"/><property name="sex" value="男"/></bean></beans>

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? ? ?Hello.java

package com.ynxinhua.bean;public class Hello {private String message;public void setMessage(String message) {this.message = message;}public String getMessage() {return message;}}

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? ? Student.java

package com.ynxinhua.bean;public class Student  {private String name;private int age;private String sex;public Student() {}public Student(String name, int age, String sex) {this.name = name;this.age = age;this.sex = sex;}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;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}}

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? ? ApplicationContext.java

package com.ynxinhua.spring;public interface ApplicationContext {public Object getbean(String beanId);//根据配置的id属性获取一个bean实例}

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? ? ClassPathXmlApplicationContext.java

package com.ynxinhua.spring;import java.lang.reflect.Method;import java.util.HashMap;import java.util.List;import java.util.Map;import org.dom4j.Document;import org.dom4j.DocumentException;import org.dom4j.Element;import org.dom4j.io.SAXReader;public class ClassPathXmlApplicationContext implements ApplicationContext {private Map beans = new HashMap();public ClassPathXmlApplicationContext(String filepath) throws Exception {SAXReader reader = new SAXReader();Document document = reader.read("bin/" + filepath);// 构建dom4j树Element root = document.getRootElement();// 获取根元素List<Element> list = root.elements("bean");// 获取所有bean元素for (Element e : list) {String beanid = e.attributeValue("id");// 获取id的属性值String className = e.attributeValue("class");// 获取class的属性值Class class1 = Class.forName(className);Object beanObject = class1.newInstance();// 实例化bean对象beans.put(beanid, beanObject);// 放入beans中List<Element> list2 = e.elements("property");for (Element e1 : list2) {String name = e1.attributeValue("name");String value = e1.attributeValue("value");// System.out.println(class1.getDeclaredField("name").getType().getName());String parameterType = class1.getDeclaredField(name).getType().getName();// 获得属性的参数类型String methodName = "set" + name.substring(0, 1).toUpperCase() + name.substring(1);Method method = null;if (parameterType.equals("int")) {method = class1.getMethod(methodName, int.class);}else{method = class1.getMethod(methodName, Class.forName(parameterType));}if (parameterType.equals("int")) {method.invoke(beanObject, Integer.parseInt(value));}else{method.invoke(beanObject, value);}}}}public Map getBeans() {return beans;}public void setBeans(Map beans) {this.beans = beans;}@Overridepublic Object getbean(String beanId) {return beans.get(beanId);}}

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? ? Demo.java

package com.ynxinhua.demo;import com.ynxinhua.bean.Hello;import com.ynxinhua.bean.Student;import com.ynxinhua.spring.ApplicationContext;import com.ynxinhua.spring.ClassPathXmlApplicationContext;public class Demo {public static void main(String[] args) throws Exception {ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");Hello hello=(Hello) context.getbean("hello");System.out.println(hello.getMessage());Student student=(Student) context.getbean("student");System.out.println(student.getName());System.out.println(student.getAge());System.out.println(student.getSex());}}

? ? 例子源码见附件.导入myeclipse运行的时候需要dom4j的jar包

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