@@ -0,0 +1,1569 @@
+package com.alibaba.nacos.client;%0A%0Aimport com.alibaba.nacos.client.utils.StringUtils;%0Aimport org.junit.Test;%0A%0Aimport java.util.ArrayList;%0Aimport java.util.Collection;%0A%0Aimport static org.junit.Assert.*;%0Aimport static com.alibaba.nacos.client.utils.StringUtils.*;%0A%0Apublic class StringUtilsTest %7B%0A%0A    @Test%0A    public void testisNotBlank() %7B%0A        assertTrue(isNotBlank(%22foo%22));%0A%0A        assertFalse(isNotBlank(%22 %22));%0A        assertFalse(isNotBlank(null));%0A    %7D%0A%0A    @Test%0A    public void testIsNotEmpty() %7B%0A        assertFalse(isNotEmpty(%22%22));%0A%0A        assertTrue(isNotEmpty(%22foo%22));%0A    %7D%0A%0A    @Test%0A    public void testDefaultIfEmpty() %7B%0A        assertEquals(%22foo%22, defaultIfEmpty(%22%22, %22foo%22));%0A        assertEquals(%22bar%22, defaultIfEmpty(%22bar%22, %22foo%22));%0A    %7D%0A%0A    @Test%0A    public void testEquals() %7B%0A        assertTrue(StringUtils.equals(%22foo%22, %22foo%22));%0A%0A        assertFalse(StringUtils.equals(%22bar%22, %22foo%22));%0A        assertFalse(StringUtils.equals(%22 %22, %22foo%22));%0A        assertFalse(StringUtils.equals(%22foo%22, null));%0A    %7D%0A%0A    @Test%0A    public void testSubstringBetween() %7B%0A        assertNull(substringBetween(null, null, null));%0A        assertNull(substringBetween(%22%22, %22foo%22, %22%22));%0A        assertNull(substringBetween(%22foo%22, %22bar%22, %22baz%22));%0A%0A        assertEquals(%22%22, substringBetween(%22foo%22, %22foo%22, %22%22));%0A    %7D%0A%0A    @Test%0A    public void testJoin() %7B%0A        assertNull(join(null, %22%22));%0A%0A        Collection collection = new ArrayList();%0A        collection.add(%22foo%22);%0A        collection.add(%22bar%22);%0A        assertEquals(%22foo,bar%22, join(collection, %22,%22));%0A    %7D%0A%7D%0A

Add unit tests for com.alibaba.nacos.client.utils.StringUtils