Java通过反射机制,动态设置对象属性值

偏执的太偏执、 2023-10-04 11:01 32阅读 0赞

###### 1 : 测试截图 ######

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MjU0NjM1_size_16_color_FFFFFF_t_70]

###### 2 : 工具类 ######

package util;
    
    import lombok.extern.slf4j.Slf4j;
    import org.apache.commons.lang.time.DateFormatUtils;
    import java.lang.reflect.Field;
    import java.lang.reflect.Method;
    import java.math.BigDecimal;
    import java.sql.Timestamp;
    import java.time.LocalDate;
    import java.time.LocalDateTime;
    import java.time.ZoneId;
    import java.time.format.DateTimeFormatter;
    import java.util.Date;
    import java.util.HashMap;
    import java.util.Map;
    
    @Slf4j
    public class InvokeUtil {
        
    
        public static void main(String[] args) {
        
            Map<String, String> valMap = new HashMap<String, String>();
            valMap.put("name", "测试");
            valMap.put("statue", "a");
            valMap.put("age", "23");
            valMap.put("height", "173.5");
            valMap.put("weight", "53.7");
            valMap.put("amount", "573");
            valMap.put("number", "1");
            valMap.put("work", "2");
            valMap.put("fund", "4.1");
            valMap.put("date", "2021-12-31");
            valMap.put("time", "2021-12-31 23:34:11");
            valMap.put("dateTime", "1618560281465");
            valMap.put("flag", "false");
            InvokeEntity entity = new InvokeEntity();
            setBeanFieldValue(entity, valMap);
            System.out.println("反射赋值：" + entity.toString());
            System.out.println("反射取值:");
            Map<String, String> fieldValMap = getBeanFieldValue(entity);
            for (Map.Entry<String, String> entry : fieldValMap.entrySet()) {
        
                System.out.println("字段名：["+entry.getKey()+"],字段值：[" + entry.getValue()+"]");
            }
        }
    
        /**
         * get bean field value to value map
         * @param bean java bean
         * @return value map K:field V:value
         */
        public static Map<String, String> getBeanFieldValue(Object bean) {
        
            Class<?> beanClass = bean.getClass();
            Map<String, String> valueMap = new HashMap<String, String>();
            Method[] methods = beanClass.getDeclaredMethods();
            Field[] fields = beanClass.getDeclaredFields();
            for (Field field : fields) {
        
                try {
        
                    String fieldGetMethodName = spliceGetMethod(field.getName());
                    if (!checkPropertyMethodExist(methods, fieldGetMethodName)) continue;
                    Method fieldGetMethod = beanClass.getMethod(fieldGetMethodName, new Class[] {
        });
                    Object fieldValue = fieldGetMethod.invoke(bean, new Object[] {
        });
                    if(null != fieldValue){
        
                        if ("Date".equals(field.getType().getSimpleName())) {
        
                            valueMap.put(field.getName(), DateFormatUtils.format((Date)fieldValue, "yyyy-MM-dd HH:mm:ss"));
                            continue;
                        }
                        valueMap.put(field.getName(), String.valueOf(fieldValue));
                    }
                } catch (Exception e) {
        
                    log.error("get bean value error" + field, e);
                }
            }
            return valueMap;
        }
    
        /**
         * set bean field value by value map
         * @param bean java bean
         * @param valueMap value map K:field V:value
         */
        public static void setBeanFieldValue(Object bean, Map<String, String> valueMap) {
        
            Class<?> beanClass = bean.getClass();
            Method[] methods = beanClass.getDeclaredMethods();
            Field[] fields = beanClass.getDeclaredFields();
            for (Field field : fields) {
        
                try {
        
                    String fieldSetName = spliceSetMethod(field.getName());
                    if (!checkPropertyMethodExist(methods, fieldSetName)) continue;
                    Method fieldSetMet = beanClass.getMethod(fieldSetName, field.getType());
                    String value = valueMap.get(field.getName());
                    fieldSetMet.invoke(bean, getFieldTypeValue(field, value));
                } catch (Exception e) {
        
                    log.error("set bean value error" + field, e);
                }
            }
        }
    
        /**
         * return the corresponding type value according to the field property
         * @param field the field
         * @param value original value
         * @return corresponding type value
         */
        public static Object getFieldTypeValue(Field field, Object value){
        
            if(null == field || null == value || "".equals(value)) return null;
            String fieldType = field.getType().getSimpleName();
            if ("String".equals(fieldType)) return String.valueOf(value);
            if ("Date".equals(fieldType)) {
        
                if (String.valueOf(value).indexOf(':') > 0) return Date.from(LocalDateTime.parse(String.valueOf(value), DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")).atZone(ZoneId.systemDefault()).toInstant());
                return Date.from(LocalDate.parse(String.valueOf(value), DateTimeFormatter.ofPattern("yyyy-MM-dd")).atStartOfDay(ZoneId.systemDefault()).toInstant());
            }
            if ("Integer".equals(fieldType) || "int".equals(fieldType)) return Integer.parseInt(String.valueOf(value));
            if ("Long".equalsIgnoreCase(fieldType)) return Long.parseLong(String.valueOf(value));
            if ("Float".equalsIgnoreCase(fieldType)) return Float.parseFloat(String.valueOf(value));
            if ("Double".equalsIgnoreCase(fieldType)) return Double.parseDouble(String.valueOf(value));
            if ("Short".equalsIgnoreCase(fieldType)) return Short.parseShort(String.valueOf(value));
            if ("Byte".equalsIgnoreCase(fieldType)) return Byte.parseByte(String.valueOf(value));
            if ("BigDecimal".equalsIgnoreCase(fieldType)) return new BigDecimal(String.valueOf(value));
            if ("Character".equals(fieldType) || "char".equals(fieldType)) return String.valueOf(value).charAt(0);
            if ("Boolean".equalsIgnoreCase(fieldType)) return Boolean.parseBoolean(String.valueOf(value));
            if ("TimeStamp".equalsIgnoreCase(fieldType)) return new Timestamp(Long.valueOf(String.valueOf(value)));
            return value;
        }
    
        /**
         * judge whether it exists method of a property
         * @param methods object property method list
         * @param fieldMethod get or set method
         * @return true: exist, false: not exist
         */
        public static boolean checkPropertyMethodExist(Method[] methods, String fieldMethod) {
        
            if(null == fieldMethod || "".equals(fieldMethod)) return false;
            for (Method met : methods) {
        
                if (fieldMethod.equals(met.getName())) return true;
            }
            return false;
        }
    
        /**
         * splicing property get or set methods
         * @param fieldName property name
         * @param method get or set method
         * @return methods after splicing
         */
        public static String splicePropertyMethod(String fieldName, String method) {
        
            if (null == fieldName || "".equals(fieldName)) return null;
            return method + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);
        }
    
        /**
         * splicing property get method
         * @param fieldName property
         * @return get method after splicing
         */
        public static String spliceGetMethod(String fieldName) {
        
            return splicePropertyMethod(fieldName, "get");
        }
    
        /**
         * splicing property set method
         * @param fieldName property
         * @return set method after splicing
         */
        public static String spliceSetMethod(String fieldName) {
        
            return splicePropertyMethod(fieldName, "set");
        }
    
    }

###### 3 : 测试Bean ######

package util;
    
    import java.sql.Timestamp;
    import java.math.BigDecimal;
    import java.util.Date;
    
    public class InvokeEntity {
        
    
        private String name;
        private Character statue;
        private Integer age;
        private Float height;
        private Double weight;
        private Long amount;
        private Short number;
        private Byte work;
        private BigDecimal fund;
        private Date date;
        private Date time;
        private Timestamp dateTime;
        private boolean flag;
    
        public String getName() {
        
            return name;
        }
    
        public void setName(String name) {
        
            this.name = name;
        }
    
        public Character getStatue() {
        
            return statue;
        }
    
        public void setStatue(Character statue) {
        
            this.statue = statue;
        }
    
        public Integer getAge() {
        
            return age;
        }
    
        public void setAge(Integer age) {
        
            this.age = age;
        }
    
        public Float getHeight() {
        
            return height;
        }
    
        public void setHeight(Float height) {
        
            this.height = height;
        }
    
        public Double getWeight() {
        
            return weight;
        }
    
        public void setWeight(Double weight) {
        
            this.weight = weight;
        }
    
        public Long getAmount() {
        
            return amount;
        }
    
        public void setAmount(Long amount) {
        
            this.amount = amount;
        }
    
        public Short getNumber() {
        
            return number;
        }
    
        public void setNumber(Short number) {
        
            this.number = number;
        }
    
        public Byte getWork() {
        
            return work;
        }
    
        public void setWork(Byte work) {
        
            this.work = work;
        }
    
        public BigDecimal getFund() {
        
            return fund;
        }
    
        public void setFund(BigDecimal fund) {
        
            this.fund = fund;
        }
    
        public Date getDate() {
        
            return date;
        }
    
        public void setDate(Date date) {
        
            this.date = date;
        }
    
        public Date getTime() {
        
            return time;
        }
    
        public void setTime(Date time) {
        
            this.time = time;
        }
    
        public Timestamp getDateTime() {
        
            return dateTime;
        }
    
        public void setDateTime(Timestamp dateTime) {
        
            this.dateTime = dateTime;
        }
    
        public boolean isFlag() {
        
            return flag;
        }
    
        public void setFlag(boolean flag) {
        
            this.flag = flag;
        }
    
        @Override
        public String toString() {
        
            return "InvokeEntity{" +
                    "name='" + name + '\'' +
                    ", statue=" + statue +
                    ", age=" + age +
                    ", height=" + height +
                    ", weight=" + weight +
                    ", amount=" + amount +
                    ", number=" + number +
                    ", work=" + work +
                    ", fund=" + fund +
                    ", date=" + date +
                    ", time=" + time +
                    ", dateTime=" + dateTime +
                    ", flag=" + flag +
                    '}';
        }
    }

###### 4 : 参考链接 ######

[http://www.itxm.cn/post/2706.html][http_www.itxm.cn_post_2706.html]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MjU0NjM1_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20210416162745136.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4MjU0NjM1,size_16,color_FFFFFF,t_70
[http_www.itxm.cn_post_2706.html]: http://www.itxm.cn/post/2706.html