BAEL-3045 Validate Date

Check if a string contains valid date

java-dates-2/DaveValidatorUsingLocalDate.java

@@ -0,0 +1,24 @@
+package com.baeldung.date.validation;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
+
+public class DaveValidatorUsingLocalDate implements DateValidator {
+    private DateTimeFormatter dateFormatter;
+    
+    public DaveValidatorUsingLocalDate(DateTimeFormatter dateFormatter) {
+        super();
+        this.dateFormatter = dateFormatter;
+    }
+
+    @Override
+    public boolean validate(String dateStr) {
+        try {
+            LocalDate.parse(dateStr, this.dateFormatter);
+        } catch (DateTimeParseException e) {
+            return false;
+        }
+        return true;
+    }
+}

java-dates-2/pom.xml

@@ -21,6 +21,13 @@
             <version>${joda-time.version}</version>
         </dependency>
         
+        <!-- https://mvnrepository.com/artifact/commons-validator/commons-validator -->
+        <dependency>
+            <groupId>commons-validator</groupId>
+            <artifactId>commons-validator</artifactId>
+            <version>1.6</version>
+        </dependency>
+
         <!-- test scoped -->
         <dependency>
             <groupId>org.assertj</groupId>

java-dates-2/src/main/java/com/baeldung/date/validation/DateValidator.java

@@ -0,0 +1,5 @@
+package com.baeldung.date.validation;
+
+public interface DateValidator {
+   public boolean isValid(String dateStr);
+}

java-dates-2/src/main/java/com/baeldung/date/validation/DateValidatorUsingApacheValidator.java

@@ -0,0 +1,11 @@
+package com.baeldung.date.validation;
+
+import org.apache.commons.validator.GenericValidator;
+
+public class DateValidatorUsingApacheValidator implements DateValidator {
+
+    @Override
+    public boolean isValid(String dateStr) {
+        return GenericValidator.isDate(dateStr, "yyyy-MM-dd", true); 
+    }
+}

java-dates-2/src/main/java/com/baeldung/date/validation/DateValidatorUsingDateFormat.java

@@ -0,0 +1,25 @@
+package com.baeldung.date.validation;
+
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+public class DateValidatorUsingDateFormat implements DateValidator {
+    private String dateFormat;
+
+    public DateValidatorUsingDateFormat(String dateFormat) {
+        this.dateFormat = dateFormat;
+    }
+
+    @Override
+    public boolean isValid(String dateStr) {
+        DateFormat sdf = new SimpleDateFormat(this.dateFormat);
+        sdf.setLenient(false);
+        try {
+            sdf.parse(dateStr);
+        } catch (ParseException e) {
+            return false;
+        }
+        return true;
+    }
+}

java-dates-2/src/main/java/com/baeldung/date/validation/DateValidatorUsingDateTimeFormatter.java

@@ -0,0 +1,22 @@
+package com.baeldung.date.validation;
+
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
+
+public class DateValidatorUsingDateTimeFormatter implements DateValidator {
+    private DateTimeFormatter dateFormatter;
+    
+    public DateValidatorUsingDateTimeFormatter(DateTimeFormatter dateFormatter) {
+        this.dateFormatter = dateFormatter;
+    }
+
+    @Override
+    public boolean isValid(String dateStr) {
+        try {
+            this.dateFormatter.parse(dateStr);
+        } catch (DateTimeParseException e) {
+            return false;
+        }
+        return true;
+    }
+}

java-dates-2/src/main/java/com/baeldung/date/validation/DateValidatorUsingLocalDate.java

@@ -0,0 +1,23 @@
+package com.baeldung.date.validation;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+import java.time.format.DateTimeParseException;
+
+public class DateValidatorUsingLocalDate implements DateValidator {
+    private DateTimeFormatter dateFormatter;
+    
+    public DateValidatorUsingLocalDate(DateTimeFormatter dateFormatter) {
+        this.dateFormatter = dateFormatter;
+    }
+
+    @Override
+    public boolean isValid(String dateStr) {
+        try {
+            LocalDate.parse(dateStr, this.dateFormatter);
+        } catch (DateTimeParseException e) {
+            return false;
+        }
+        return true;
+    }
+}

java-dates-2/src/test/java/com/baeldung/date/validation/DateValidatorUsingApacheValidatorUnitTest.java

@@ -0,0 +1,20 @@
+package com.baeldung.date.validation;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.apache.commons.validator.GenericValidator;
+import org.junit.Test;
+
+public class DateValidatorUsingApacheValidatorUnitTest {
+
+    @Test
+    public void whenValidDatePassed_ThenTrue() {
+        assertTrue(GenericValidator.isDate("2019-02-28", "yyyy-MM-dd", true));
+    }
+
+    @Test
+    public void whenInvalidDatePassed_ThenFalse() {
+        assertFalse(GenericValidator.isDate("2019-02-29", "yyyy-MM-dd", true));
+    }
+}

java-dates-2/src/test/java/com/baeldung/date/validation/DateValidatorUsingDateFormatUnitTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.date.validation;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class DateValidatorUsingDateFormatUnitTest {
+    
+    @Test
+    public void givenValidator_whenValidDatePassed_ThenTrue() {
+        DateValidator validator = new DateValidatorUsingDateFormat("MM/dd/yyyy");
+        
+        assertTrue(validator.isValid("02/28/2019"));
+    }
+    
+    @Test
+    public void givenValidator_whenInvalidDatePassed_ThenFalse() {
+        DateValidator validator = new DateValidatorUsingDateFormat("MM/dd/yyyy");
+        
+        assertFalse(validator.isValid("02/30/2019"));
+    }
+}

java-dates-2/src/test/java/com/baeldung/date/validation/DateValidatorUsingDateTimeFormatterUnitTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.date.validation;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.time.format.DateTimeFormatter;
+import java.time.format.ResolverStyle;
+import java.util.Locale;
+
+import org.junit.Test;
+
+public class DateValidatorUsingDateTimeFormatterUnitTest {
+    
+    @Test
+    public void givenValidator_whenValidDatePassed_ThenTrue() {
+        DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern("uuuu-MM-dd", Locale.US)
+            .withResolverStyle(ResolverStyle.STRICT);
+        DateValidator validator = new DateValidatorUsingDateTimeFormatter(dateFormatter);
+        
+        assertTrue(validator.isValid("2019-02-28"));
+    }
+    
+    @Test
+    public void givenValidator_whenInValidDatePassed_ThenFalse() {
+        DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern("uuuu-MM-dd", Locale.US)
+            .withResolverStyle(ResolverStyle.STRICT);
+        DateValidator validator = new DateValidatorUsingDateTimeFormatter(dateFormatter);
+        
+        assertFalse(validator.isValid("2019-02-30"));
+    }
+
+}

java-dates-2/src/test/java/com/baeldung/date/validation/DateValidatorUsingLocalDateUnitTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.date.validation;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import java.time.format.DateTimeFormatter;
+
+import org.junit.Test;
+
+public class DateValidatorUsingLocalDateUnitTest {
+    
+    @Test
+    public void givenValidator_whenValidDatePassed_ThenTrue() {
+        DateTimeFormatter dateFormatter = DateTimeFormatter.BASIC_ISO_DATE;
+        DateValidator validator = new DateValidatorUsingLocalDate(dateFormatter);
+        
+        assertTrue(validator.isValid("20190228"));
+    }
+    
+    @Test
+    public void givenValidator_whenInValidDatePassed_ThenFalse() {
+        DateTimeFormatter dateFormatter = DateTimeFormatter.BASIC_ISO_DATE;
+        DateValidator validator = new DateValidatorUsingLocalDate(dateFormatter);
+        
+        assertFalse(validator.isValid("20190230"));
+    }
+}