List转实体类

Posted 2022-04-09 ispotu

自己复制试验一下，理解处理过程对你长进促进很大

实例：

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

public class ListToModel 
    public static void main(String[] args) 
        List<Object> userList = new ArrayList<Object>();
        userList.add("tom");
        userList.add("男");
        userList.add(18);
        User user = new User();
        try 
            listToModel(userList, user);
         catch (Exception e) 
            e.printStackTrace();
        
        System.out.println(user.getName() + "; " + user.getGender() + "; " + user.getAge());

    
    
    //把list内容逐个取出来放进User实体类中
    public static <T> void listToModel(List<Object> list, T t) throws Exception 
        Field[] fields = t.getClass().getDeclaredFields();
        if (list.size() != fields.length) 
            return;
        
        for (int k = 0, len = fields.length; k < len; k++) 
            // 根据属性名称,找寻合适的set方法
            String fieldName = fields[k].getName();
            String setMethodName = "set" + fieldName.substring(0, 1).toUpperCase()
                    + fieldName.substring(1);
            Method method = null;
            Class<?> clazz = t.getClass();
            try 
                method = clazz.getMethod(setMethodName, new Class[]  list.get(k).getClass() );
                System.out.println("list.get("+k+").getClass():"+list.get(k).getClass());
             catch (SecurityException e1) 
                e1.printStackTrace();
                return;
             catch (NoSuchMethodException e1) 
                String newMethodName = "set" + fieldName.substring(0, 1).toLowerCase()
                        + fieldName.substring(1);
                try 
                    method = clazz.getMethod(newMethodName, new Class[]  list.get(k).getClass() );
                 catch (SecurityException e) 
                    e.printStackTrace();
                    return;
                 catch (NoSuchMethodException e) 
                    e.printStackTrace();
                    return;
                
            
            if (method == null) 
                return;
            
            method.invoke(t, new Object[]  list.get(k) );
        
    

class User
	private String name;
	private String gender;
	private Integer age;
	public String getName() 
		return name;
	
	public void setName(String name) 
		this.name = name;
	
	public String getGender() 
		return gender;
	
	public void setGender(String gender) 
		this.gender = gender;
	
	public Integer getAge() 
		return age;
	
	public void setAge(Integer age) 
		this.age = age;
	

实体类userList的元素类型要处理好，其元素都是封装类型的，比如数字类型是Integer，Double，Float等等。与User要对应处理起来更方便，不然报错不断。