Spring基本原理模拟(IoC部分)

标签：util   break   targe   instance   class   attr   cas   ase   原理   

package ioc;

import java.io.File;
import java.lang.reflect.Method;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;

public class MyXmlApplicationContext implements ApplicationContext {
    private Map<String, Object> objectPool = Collections
            .synchronizedMap(new HashMap<String, Object>());
    private Document doc;
    private Element root;

    public MyXmlApplicationContext(String filePath) throws Exception {
        SAXReader reader = new SAXReader();
        doc = reader.read(new File(filePath));
        root = doc.getRootElement();
        intitPool();
        intitProp();
    }

    @Override
    public Object getBean(String name) throws Exception {
        Object target = objectPool.get(name);
        if (target.getClass() != String.class) {
            return target;
        } else {
            String clazz = (String) target;
            return Class.forName(clazz).newInstance();
        }
    }

    private void intitProp() throws Exception {
        for (Object obj : root.elements()) {
            Element beanEle = (Element) obj;
            String beanId = beanEle.attributeValue("id");
            String beanScope = beanEle.attributeValue("scope");
            if (beanScope == null || beanScope.equals("singleton")) {
                Object bean = objectPool.get(beanId);
                for (Object prop : beanEle.elements()) {
                    Element propEle = (Element) prop;
                    String propName = propEle.attributeValue("name");
                    String propValue = propEle.attributeValue("value");
                    String propRef = propEle.attributeValue("ref");
                    String propNameCamlize = propName.substring(0, 1)
                            .toUpperCase()
                            + propName.substring(1, propName.length());
                    if (propValue != null && propValue.length() > 0) {
                        Method setter = bean.getClass().getMethod(
                                "set" + propNameCamlize, String.class);
                        setter.invoke(bean, propValue);
                    }
                    if (propRef != null && propRef.length() > 0) {
                        Object target = objectPool.get(propRef);
                        if (target == null) {

                        }

                        Method setter = null;
                        for (Class<?> superInteface : target.getClass()
                                .getInterfaces()) {
                            try {
                                setter = bean.getClass().getMethod(
                                        "set" + propNameCamlize, superInteface);
                                break;
                            } catch (NoSuchMethodException ex) {
                                continue;
                            }
                        }
                        if (setter == null) {
                            setter = bean.getClass().getMethod(
                                    "set" + propNameCamlize, target.getClass());
                        }
                        setter.invoke(bean, target);
                    }
                }
            }

        }

    }

    private void intitPool() throws Exception {
        for (Object obj : root.elements()) {
            Element beanEle = (Element) obj;
            String beanId = beanEle.attributeValue("id");
            String beanClass = beanEle.attributeValue("class");
            String beanScope = beanEle.attributeValue("scope");
            if (beanScope == null || beanScope.equals("singleton")) {
                objectPool.put(beanId, Class.forName(beanClass).newInstance());
            } else {
                objectPool.put(beanId, beanClass);
            }
        }

    }

}

Spring基本原理模拟(IoC部分)

标签：util   break   targe   instance   class   attr   cas   ase   原理   

原文地址：https://www.cnblogs.com/caoleiCoding/p/9250233.html