优化儒略日计算；使用最新寿星天文历算法修复节气误差。

src/main/java/com/nlf/calendar/Solar.java

@@ -105,55 +105,46 @@ public class Solar{
    * @param julianDay 儒略日
    */
   public Solar(double julianDay){
-    julianDay += 0.5;
+    int d = (int)(julianDay + 0.5);
+    double f = julianDay + 0.5 - d;
+    int c;
 
-    // 日数的整数部份
+    if (d >= 2299161) {
-    double a = int2(julianDay);
+      c = (int)((d - 1867216.25) / 36524.25);
-    // 日数的小数部分
+      d += 1 + c - (int)(c * 1D / 4);
-    double f = julianDay - a;
-    double jd;
-
-    if (a > 2299161) {
-      jd = int2((a - 1867216.25) / 36524.25);
-      a += 1 + jd - int2(jd / 4);
     }
-    // 向前移4年零2个月
+    d += 1524;
-    a += 1524;
+    int year = (int)((d - 122.1) / 365.25);
-    double y = int2((a - 122.1) / 365.25);
+    d -= (int)(365.25 * year);
-    // 去除整年日数后余下日数
+    int month = (int)(d * 1D / 30.601);
-    jd = a - int2(365.25 * y);
+    d -= (int)(30.601 * month);
-    double m = (int)int2(jd / 30.6001);
+    int day = d;
-    // 去除整月日数后余下日数
+    if (month > 13) {
-    double d = (int)int2(jd - int2(m * 30.6001));
+      month -= 13;
-    y -= 4716;
+      year -= 4715;
-    m--;
+    } else {
-    if (m > 12) {
+      month -= 1;
-      m -= 12;
+      year -= 4716;
     }
-    if (m <= 2) {
-      y++;
-    }
-
-    // 日的小数转为时分秒
     f *= 24;
-    double h = (int)int2(f);
+    int hour = (int)f;
 
-    f -= h;
+    f -= hour;
     f *= 60;
-    double mi = int2(f);
+    int minute = (int)f;
 
-    f -= mi;
+    f -= minute;
     f *= 60;
-    double s = int2(f);
+    int second = (int)Math.round(f);
 
     calendar = Calendar.getInstance();
-    calendar.set((int)y,(int)m-1,(int)d,(int)h,(int)mi,(int)s);
+    calendar.set(year,month-1,day,hour,minute,second);
-    year = calendar.get(Calendar.YEAR);
+    this.year = year;
-    month = calendar.get(Calendar.MONTH)+1;
+    this.month = month;
-    day = calendar.get(Calendar.DATE);
+    this.day = day;
-    hour = calendar.get(Calendar.HOUR_OF_DAY);
+    this.hour = hour;
-    minute = calendar.get(Calendar.MINUTE);
+    this.minute = minute;
-    second = calendar.get(Calendar.SECOND);
+    this.second = second;
   }
 
   /**
@@ -388,38 +379,28 @@ public class Solar{
     return new Lunar(calendar.getTime());
   }
 
-  private double int2(double v){
-    v = Math.floor(v);
-    return v<0?v+1:v;
-  }
-
   /**
    * 获取儒略日
    * @return 儒略日
    */
   public double getJulianDay(){
-    double y = this.year;
+    int y = this.year;
-    double m = this.month;
+    int m = this.month;
-    double n = 0;
+    double d = this.day + ((this.second *1D / 60 + this.minute) / 60 + this.hour) / 24;
-
+    int n = 0;
+    boolean g = false;
+    if (y * 372 + m * 31 + (int)d >= 588829) {
+      g = true;
+    }
     if (m <= 2) {
       m += 12;
       y--;
     }
-
+    if (g) {
-    // 判断是否为UTC日1582*372+10*31+15
+      n = (int)(y * 1D / 100);
-    if (this.year * 372 + this.month * 31 + this.day >= 588829) {
+      n = 2 - n + (int)(n * 1D / 4);
-      n = int2(y / 100);
-      // 加百年闰
-      n = 2 - n + int2(n / 4);
     }
-
+    return (int)(365.25 * (y + 4716)) + (int)(30.6001 * (m + 1)) + d + n - 1524.5;
-    // 加上年引起的偏移日数
-    n += int2(365.2500001 * (y + 4716));
-    // 加上月引起的偏移日数及日偏移数
-    n += int2(30.6 * (m + 1)) + this.day;
-    n += ((this.second *1D / 60 + this.minute) / 60 + this.hour) / 24 - 1524.5;
-    return n;
   }
 
   /**

src/test/java/test/JiQiTest.java

@@ -0,0 +1,98 @@
+package test;
+
+import com.nlf.calendar.Solar;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * 节气测试
+ *
+ * @author 6tail
+ */
+public class JiQiTest {
+
+  @Test
+  public void test2022() {
+
+    Map<String,String> jieQi = new HashMap<String, String>(){
+      private static final long serialVersionUID = 1L;
+      {
+        put("冬至","2021-12-21 23:59:09");
+        put("小寒","2022-01-05 17:13:54");
+        put("大寒","2022-01-20 10:38:56");
+        put("立春","2022-02-04 04:50:36");
+        put("雨水","2022-02-19 00:42:50");
+        put("惊蛰","2022-03-05 22:43:34");
+        put("春分","2022-03-20 23:33:15");
+        put("清明","2022-04-05 03:20:03");
+        put("谷雨","2022-04-20 10:24:07");
+        put("立夏","2022-05-05 20:25:46");
+        put("小满","2022-05-21 09:22:25");
+        put("芒种","2022-06-06 00:25:37");
+        put("夏至","2022-06-21 17:13:40");
+        put("小暑","2022-07-07 10:37:49");
+        put("大暑","2022-07-23 04:06:49");
+        put("立秋","2022-08-07 20:28:57");
+        put("处暑","2022-08-23 11:15:59");
+        put("白露","2022-09-07 23:32:07");
+        put("秋分","2022-09-23 09:03:31");
+        put("寒露","2022-10-08 15:22:16");
+        put("霜降","2022-10-23 18:35:31");
+        put("立冬","2022-11-07 18:45:18");
+        put("小雪","2022-11-22 16:20:18");
+        put("大雪","2022-12-07 11:46:04");
+      }
+    };
+
+    Solar solar = Solar.fromYmd(2022, 7, 15);
+    Map<String,Solar> result = solar.getLunar().getJieQiTable();
+    for(Map.Entry<String,String> entry:jieQi.entrySet()){
+      String name = entry.getKey();
+      Assert.assertEquals(name, entry.getValue(), result.get(name).toYmdHms());
+    }
+  }
+
+  @Test
+  public void test1986() {
+
+    Map<String,String> jieQi = new HashMap<String, String>(){
+      private static final long serialVersionUID = 1L;
+      {
+        put("冬至","1985-12-22 06:07:40");
+        put("小寒","1986-01-05 23:28:02");
+        put("大寒","1986-01-20 16:46:12");
+        put("立春","1986-02-04 11:07:42");
+        put("雨水","1986-02-19 06:57:31");
+        put("惊蛰","1986-03-06 05:12:08");
+        put("春分","1986-03-21 06:02:41");
+        put("清明","1986-04-05 10:06:07");
+        put("谷雨","1986-04-20 17:12:08");
+        put("立夏","1986-05-06 03:30:36");
+        put("小满","1986-05-21 16:27:55");
+        put("芒种","1986-06-06 07:44:23");
+        put("夏至","1986-06-22 00:29:57");
+        put("小暑","1986-07-07 18:00:45");
+        put("大暑","1986-07-23 11:24:23");
+        put("立秋","1986-08-08 03:45:36");
+        put("处暑","1986-08-23 18:25:47");
+        put("白露","1986-09-08 06:34:37");
+        put("秋分","1986-09-23 15:58:52");
+        put("寒露","1986-10-08 22:06:45");
+        put("霜降","1986-10-24 01:14:11");
+        put("立冬","1986-11-08 01:12:49");
+        put("小雪","1986-11-22 22:44:20");
+        put("大雪","1986-12-07 18:00:56");
+      }
+    };
+
+    Solar solar = Solar.fromYmd(1986, 7, 15);
+    Map<String,Solar> result = solar.getLunar().getJieQiTable();
+    for(Map.Entry<String,String> entry:jieQi.entrySet()){
+      String name = entry.getKey();
+      Assert.assertEquals(name, entry.getValue(), result.get(name).toYmdHms());
+    }
+  }
+}

src/test/java/test/JulianDayTest.java

@@ -0,0 +1,25 @@
+package test;
+
+import com.nlf.calendar.Solar;
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * 儒略日测试
+ *
+ * @author 6tail
+ */
+public class JulianDayTest {
+
+  @Test
+  public void testSolar2JD() {
+    Solar solar = Solar.fromYmd(2020, 7, 15);
+    Assert.assertEquals(2459045.5, solar.getJulianDay(), 0);
+  }
+
+  @Test
+  public void testJD2Solar() {
+    Solar solar = Solar.fromJulianDay(2459045.5);
+    Assert.assertEquals("2020-07-15 00:00:00", solar.toYmdHms());
+  }
+}