手寫模擬使用java reflect 實現 Spring IOC DI

package com.base.reflect;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

import static java.lang.Class.*;

public class MySpringBean {
    public static Object getBean(String className,Class[] constructorParamType,Object[] constructorArg,Map<String,Object> param) {
        Object obj=null;
        try {
            Class clazz = forName(className);
            if(constructorParamType!=null&&constructorParamType.length>0) {
                Constructor constructor = clazz.getConstructor(constructorParamType);
                obj = constructor.newInstance(constructorArg);
            }else {
                obj = clazz.newInstance();
            }
            Field[] fields= clazz.getDeclaredFields();
            for(Field field: fields){
                Class fieldClass = field.getType();
                String fieldClassName = fieldClass.getName();
                System.out.println("fieldClassName--->"+fieldClassName);
                String fieldName =field.getName();
                Method setMethod = clazz.getMethod("set"+fieldName.substring(0,1).toUpperCase()+fieldName.substring(1),fieldClass);
                if(setMethod!=null) {
                    Object fieldValue = param.get(className + "." + fieldName);
                    if(fieldValue!=null) {
                        if ("java.lang.Integer".equals(fieldClassName) || "java.lang.String".equals(fieldClassName) || "java.lang.Double".equals(fieldClassName)
                                || "java.lang.Long".equals(fieldClassName) || "java.lang.Short".equals(fieldClassName)
                                || "java.lang.Short".equals(fieldClassName) || "java.lang.Byte".equals(fieldClassName)) {
                            Constructor con = fieldClass.getConstructor(String.class);
                            setMethod.invoke(obj, con.newInstance(fieldValue));
                        } else {
                            setMethod.invoke(obj, fieldValue);
                        }
                    }
                }

            }


        }catch (ClassNotFoundException e){

        }catch (Exception e){

        }

        return obj;

    }

    public static void main(String[] args) {
        Map<String,Object> likeParam=new HashMap<String,Object>();
        likeParam.put("com.base.reflect.Like.name","喜歡唱歌");

        Map<String,Object> param=new HashMap<String,Object>();
        //param.put("com.base.reflect.Person.id","1");
        param.put("com.base.reflect.Person.name","張三");
        param.put("com.base.reflect.Person.age","10");
        param.put("com.base.reflect.Person.sex",1);
        param.put("com.base.reflect.Person.membered",true);
        param.put("com.base.reflect.Person.like",(Like) MySpringBean.getBean("com.base.reflect.Like",null,null,likeParam));
        Class[] constructorParamType=new Class[]{String.class};
        Object[] constructorArg = new Object[]{"初始化構造函數值"};
        Person person = (Person) MySpringBean.getBean("com.base.reflect.Person",constructorParamType,constructorArg,param);
        System.out.println(person.toString());
    }
}

package com.base.reflect;

public class Like {
    private String name;

    public String getName() {
        return name;
    }

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

 

package com.base.reflect;

public class Person {
    private String name;
    private Integer age;
    private int sex;
    private Boolean membered;
    private Like like;

    public String getName() {
        return name;
    }

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

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }


    public Like getLike() {
        return like;
    }

    public void setLike(Like like) {
        this.like = like;
    }

    public int getSex() {
        return sex;
    }

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

    public Boolean getMembered() {
        return membered;
    }

    public void setMembered(Boolean membered) {
        this.membered = membered;
    }

    @Override
    public String toString(){
        return "name:"+this.name+",age:"+this.age+",like:"+(this.like!=null?this.like.getName():"")+",sex:"+this.sex+",membered:"+this.membered;
    }
}