通过Java反射机制，动态给对象属性赋值，并获取属性值

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package com.matol;

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;

/*
 * 通过Java反射机制，动态给对象属性赋值，并获取属性值
 */
public class ClassRefUtil {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Map<String, String> valMap = new HashMap<String, String>();  
        valMap.put("userName", "michael");  
        valMap.put("age", "27");  
        valMap.put("height", "173.5");  
        valMap.put("date", "2010-10-24");  
        valMap.put("times", "1287932898276");  
        valMap.put("flag", "false");  
  
        ChildInfo rl = new ChildInfo(); 
        System.out.println("通过反射赋值.");  
        PublicUtil.setFieldValue(rl, valMap);  
  
        System.out.println("通过反射取值:");  
        int i = 0;
        Map<String, String> fieldValMap = PublicUtil.getFieldValueMap(rl); 
        for (Entry<String, String> entry : fieldValMap.entrySet()) {  
        	i++;
            System.out.println("[字段 "+i+"] ["+entry.getKey()+"]   ---   [" + entry.getValue()+"]");  
        }  
	}
	
	
	/** 
     * 取Bean的属性和值对应关系的MAP 
     * @param bean 
     * @return Map 
     */  
    public static Map<String, String> getFieldValueMap(Object bean) {  
        Class<?> cls = bean.getClass();  
        Map<String, String> valueMap = new HashMap<String, String>();  
        // 取出bean里的所有方法  
        Method[] methods = cls.getDeclaredMethods();  
        Field[] fields = cls.getDeclaredFields();  
  
        for (Field field : fields) {  
            try {  
                String fieldType = field.getType().getSimpleName();  
                String fieldGetName = parGetName(field.getName());  
                if (!checkGetMet(methods, fieldGetName)) {  
                    continue;  
                }  
                Method fieldGetMet = cls.getMethod(fieldGetName, new Class[] {});  
                Object fieldVal = fieldGetMet.invoke(bean, new Object[] {});  
                String result = null;  
                if ("Date".equals(fieldType)) {  
                    result = fmtDate((Date) fieldVal);  
                } else {  
                    if (null != fieldVal) {  
                        result = String.valueOf(fieldVal);  
                    }  
                }  
                valueMap.put(field.getName(), result);  
            } catch (Exception e) {  
                continue;  
            }  
        }  
        return valueMap;  
  
    }  
  
    /** 
     * set属性的值到Bean 
     * @param bean 
     * @param valMap 
     */  
    public static void setFieldValue(Object bean, Map<String, String> valMap) {  
        Class<?> cls = bean.getClass();  
        // 取出bean里的所有方法  
        Method[] methods = cls.getDeclaredMethods();  
        Field[] fields = cls.getDeclaredFields();  
  
        for (Field field : fields) {  
            try {  
                String fieldSetName = parSetName(field.getName());  
                if (!checkSetMet(methods, fieldSetName)) {  
                    continue;  
                }  
                Method fieldSetMet = cls.getMethod(fieldSetName, field.getType());  
                String value = valMap.get(field.getName());  
                if (null != value && !"".equals(value)) {  
                    String fieldType = field.getType().getSimpleName();  
                    if ("String".equals(fieldType)) {  
                        fieldSetMet.invoke(bean, value);  
                    } else if ("Date".equals(fieldType)) {  
                        Date temp = parseDate(value);  
                        fieldSetMet.invoke(bean, temp);  
                    } else if ("Integer".equals(fieldType) || "int".equals(fieldType)) {  
                        Integer intval = Integer.parseInt(value);  
                        fieldSetMet.invoke(bean, intval);  
                    } else if ("Long".equalsIgnoreCase(fieldType)) {  
                        Long temp = Long.parseLong(value);  
                        fieldSetMet.invoke(bean, temp);  
                    } else if ("Double".equalsIgnoreCase(fieldType)) {  
                        Double temp = Double.parseDouble(value);  
                        fieldSetMet.invoke(bean, temp);  
                    } else if ("Boolean".equalsIgnoreCase(fieldType)) {  
                        Boolean temp = Boolean.parseBoolean(value);  
                        fieldSetMet.invoke(bean, temp);  
                    } else {  
                        System.out.println("not supper type" + fieldType);  
                    }  
                }  
            } catch (Exception e) {  
                continue;  
            }  
        }  
  
    }  
  
    /** 
     * 格式化string为Date 
     * @param datestr 
     * @return date 
     */  
    private static Date parseDate(String datestr) {  
        if (null == datestr || "".equals(datestr)) {  
            return null;  
        }  
        try {  
            String fmtstr = null;  
            if (datestr.indexOf(':') > 0) {  
                fmtstr = "yyyy-MM-dd HH:mm:ss";  
            } else {  
                fmtstr = "yyyy-MM-dd";  
            }  
            SimpleDateFormat sdf = new SimpleDateFormat(fmtstr, Locale.UK);  
            return sdf.parse(datestr);  
        } catch (Exception e) {  
            return null;  
        }  
    }  
    /** 
     * 日期转化为String 
     * @param date 
     * @return date string 
     */  
    private static String fmtDate(Date date) {  
        if (null == date) {  
            return null;  
        }  
        try {  
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.US);  
            return sdf.format(date);  
        } catch (Exception e) {  
            return null;  
        }  
    }  
  
    /** 
     * 判断是否存在某属性的 set方法 
     * @param methods 
     * @param fieldSetMet 
     * @return boolean 
     */  
    private static boolean checkSetMet(Method[] methods, String fieldSetMet) {  
        for (Method met : methods) {  
            if (fieldSetMet.equals(met.getName())) {  
                return true;  
            }  
        }  
        return false;  
    }  
    /** 
     * 判断是否存在某属性的 get方法 
     * @param methods 
     * @param fieldGetMet 
     * @return boolean 
     */  
    private static boolean checkGetMet(Method[] methods, String fieldGetMet) {  
        for (Method met : methods) {  
            if (fieldGetMet.equals(met.getName())) {  
                return true;  
            }  
        }  
        return false;  
    }  
  
    /** 
     * 拼接某属性的 get方法 
     * @param fieldName 
     * @return String 
     */  
    private static String parGetName(String fieldName) {  
        if (null == fieldName || "".equals(fieldName)) {  
            return null;  
        }  
        return "get" + fieldName.substring(0, 1).toUpperCase()  
                + fieldName.substring(1);  
    }  
    /** 
     * 拼接在某属性的 set方法 
     * @param fieldName 
     * @return String 
     */  
    private static String parSetName(String fieldName) {  
        if (null == fieldName || "".equals(fieldName)) {  
            return null;  
        }  
        return "set" + fieldName.substring(0, 1).toUpperCase()  
                + fieldName.substring(1);  
    } 

}

转载于:https://my.oschina.net/matol/blog/138386