time format parse

class/src/test/java/time/LocalDateTest.java

@@ -1,22 +1,37 @@
 package time;
 
-import java.time.LocalDate;
-import java.time.LocalDateTime;
 import lombok.extern.slf4j.Slf4j;
 import org.junit.Test;
 
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.time.temporal.TemporalAccessor;
+
 /**
  * @author kuangcp on 18-9-12-下午7:05
  */
 @Slf4j
 public class LocalDateTest {
 
-  @Test
-  public void testFromLocalDateTime() {
-    LocalDate localDate = LocalDateTime.now().toLocalDate();
-    LocalDate last = LocalDateTime.now().plusDays(-1).toLocalDate();
+    @Test
+    public void testFromLocalDateTime() {
+        LocalDate localDate = LocalDateTime.now().toLocalDate();
+        LocalDate last = LocalDateTime.now().plusDays(-1).toLocalDate();
+
+        log.info("{}", localDate);
+        log.info("{}", last);
+    }
+
+    @Test
+    public void testFormatParse() throws Exception {
+        // 注意接口使用差异
+        DateTimeFormatter format = DateTimeFormatter.ofPattern("yyyyMMdd");
+        TemporalAccessor ta = format.parse("20230804");
+        System.out.println(ta);
 
-    log.info("{}", localDate);
-    log.info("{}", last);
-  }
+        LocalDate parse = LocalDate.parse("20171018", format);
+        System.out.println(parse);
+        System.out.println(format.format(parse));
+    }
 }

class/src/test/java/time/LocalDateTimeTest.java

@@ -4,9 +4,11 @@
 import lombok.extern.slf4j.Slf4j;
 import org.junit.Test;
 
+import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.ZoneOffset;
 import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
 import java.util.Date;
 
 import static org.hamcrest.Matchers.lessThan;
@@ -61,6 +63,16 @@ public void testFormat() throws Exception {
         LocalDateTime last = LocalDateTime.parse(str, format);
         System.out.println(last);
         System.out.println(format.format(last));
+
+        format = DateTimeFormatter.ofPattern("yyyy-MM-dd");
+        System.out.println(format.format(LocalDate.now()));
+    }
+
+    @Test(expected = DateTimeParseException.class)
+    public void testParseError() throws Exception {
+        // 字符串内不含时间，解析失败
+        LocalDateTime yyyyMMdd = LocalDateTime.parse("20230804", DateTimeFormatter.ofPattern("yyyyMMdd"));
+        System.out.println(yyyyMMdd);
     }
 
 }