Java 计算均值

/**
 * 计算均值
 * <p>
 * Author YangXuyue
 * Date 2019/4/8 10:18
 */
public class ReflectionTest {

    @Test
    public void test() {
        Value v1 = new Value(BigDecimal.valueOf(4.0), BigDecimal.valueOf(9.0));
        Value v2 = new Value(BigDecimal.valueOf(8.0), null);

        List<Value> valueList = new ArrayList<Value>() {{
            add(v1);
            add(v2);
        }};
        System.out.println(calculateValue(valueList));
    }

    private Value calculateValue(List<Value> valueList) {
        Value v = new Value(null, null);
        Field[] fieldArray = v.getClass().getDeclaredFields();
        Field tempField;
        Object object, tempObject;
        BigDecimal bigDecimal, tempBigDecimal;
        for (Field field : fieldArray) {
            try {
                for (Value value : valueList) {

                    tempField = value.getClass().getDeclaredField(field.getName());
                    // 只针对BigDecimal类型的class
                    if (Objects.equals(tempField.getType(), BigDecimal.class)) {
                        tempField.setAccessible(true);
                        tempObject = tempField.get(value);
                        if (null != tempObject) {
                            field.setAccessible(true);
                            object = field.get(v);
                            if (null == object) {
                                field.set(v, tempObject);
                            } else {
                                bigDecimal = (BigDecimal) object;
                                tempBigDecimal = (BigDecimal) tempObject;
                                field.set(v, bigDecimal.add(tempBigDecimal));
                            }
                        }
                    }
                }

                int length = valueList.size();
                field.setAccessible(true);
                object = field.get(v);
                if (object instanceof BigDecimal) {
                    bigDecimal = (BigDecimal) object;
                    bigDecimal = bigDecimal.divide(BigDecimal.valueOf(length), 2, BigDecimal.ROUND_HALF_UP);
                    field.set(v, bigDecimal);
                }
            } catch (Exception e) {
                // ignored
            }
        }
        return v;
    }

    public class Value {
        private BigDecimal v1;
        private BigDecimal v2;

        public Value(BigDecimal v1, BigDecimal v2) {
            this.v1 = v1;
            this.v2 = v2;
        }

        @Override
        public String toString() {
            return ToStringBuilder.reflectionToString(this);
        }

        public BigDecimal getV1() {
            return v1;
        }

        public void setV1(BigDecimal v1) {
            this.v1 = v1;
        }

        public BigDecimal getV2() {
            return v2;
        }

        public void setV2(BigDecimal v2) {
            this.v2 = v2;
        }
    }
}
原文地址:https://www.cnblogs.com/yang21/p/10669154.html