java反射调用set和get方法的通用类

我们有一个类的字段非常多，当我们要给遍历它的值或者说给它赋值时，最笨的方法是 每一个字段去set和get。

这意味着我们可能要写几十个set和get。

那有没有更方便快捷的方法呢  

针对这种情况，我们前面已经  写了遍历的方法 也就是通过反射get属性名和属性值的 方法 ： 

java中通过反射遍历属性字段及值

 

那set呢。

我们这次 找到了一个通用类，里面包含了set和get的方法:

package com.reallyinfo.ourea.util;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;public class BeanRefUtil {/** * 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>();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);}}//String fieldKeyName = parKeyName(field.getName());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 fieldKeyName = parKeyName(field.getName());String  fieldKeyName = field.getName();String value = valMap.get(fieldKeyName);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 */public 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 */public 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 */public 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 */public 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 */public static String parGetName(String fieldName) {if (null == fieldName || "".equals(fieldName)) {return null;}int startIndex = 0;if (fieldName.charAt(0) == '_')startIndex = 1;return "get"+ fieldName.substring(startIndex, startIndex + 1).toUpperCase()+ fieldName.substring(startIndex + 1);}/** * 拼接在某属性的 set方法 *  * @param fieldName * @return String */public static String parSetName(String fieldName) {if (null == fieldName || "".equals(fieldName)) {return null;}int startIndex = 0;if (fieldName.charAt(0) == '_')startIndex = 1;return "set"+ fieldName.substring(startIndex, startIndex + 1).toUpperCase()+ fieldName.substring(startIndex + 1);}/** * 获取存储的键名称（调用parGetName） *  * @param fieldName * @return 去掉开头的get */public static String parKeyName(String fieldName) {String fieldGetName = parGetName(fieldName);if (fieldGetName != null && fieldGetName.trim() != ""&& fieldGetName.length() > 3) {return fieldGetName.substring(3);}return fieldGetName;}}

使用方法:

set的使用方法:

假设User是我们的自定义类:

 package com.reallyinfo.ourea.core.io;public class User {private String username;private String userpassword;public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getUserpassword() {return userpassword;}public void setUserpassword(String userpassword) {this.userpassword = userpassword;}}

map中键装入类的字段名  值装入字段值:

Map<String,String> map = new HashMap<String, String>();map.put("username","joe");map.put("userpassword","123456");User   user = new User();BeanRefUtil.setFieldValue(user, map);

get方法的使用:

Map<String, String> valueMap = BeanRefUtil.getFieldValueMap(user);