Merge rome-utils into rome

.gitignore

@@ -0,0 +1,4 @@
+/target
+/.settings
+/.classpath
+/.project

LICENSE

@@ -0,0 +1,203 @@
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+

README.md

@@ -0,0 +1,4 @@
+rome-utils
+==========
+
+Utility classes for ROME projects

pom.xml

@@ -0,0 +1,66 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+
+    <modelVersion>4.0.0</modelVersion>
+
+    <parent>
+        <groupId>com.rometools</groupId>
+        <artifactId>rome-parent</artifactId>
+        <version>1.6.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>rome-utils</artifactId>
+    <version>1.6.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+    <name>rome-utils</name>
+
+    <description>Utility classes for ROME projects</description>
+
+    <url>http://rometools.github.io/rome-utils/</url>
+
+    <scm>
+        <connection>scm:git:ssh://github.com/rometools/rome-utils.git</connection>
+        <developerConnection>scm:git:ssh://git@github.com/rometools/rome-utils.git</developerConnection>
+        <url>https://github.com/rometools/rome-utils</url>
+    </scm>
+
+    <developers>
+        <developer>
+            <name>Patrick Gotthard</name>
+            <url>http://www.patrick-gotthard.de</url>
+            <timezone>+1</timezone>
+        </developer>
+    </developers>
+
+    <repositories>
+        <repository>
+            <id>sonatype-nexus-snapshots</id>
+            <url>https://oss.sonatype.org/content/repositories/snapshots</url>
+            <releases>
+                <enabled>false</enabled>
+            </releases>
+            <snapshots>
+                <enabled>true</enabled>
+            </snapshots>
+        </repository>
+    </repositories>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-library</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+</project>

src/main/java/com/rometools/utils/Alternatives.java

@@ -0,0 +1,37 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+public final class Alternatives {
+
+    private Alternatives() {
+    }
+
+    /**
+     * Returns the first object that is not null
+     *
+     * @param objects The objects to process
+     * @return The first value that is not null. null when there is no not-null value
+     */
+    public static <T> T firstNotNull(final T... objects) {
+        for (final T object : objects) {
+            if (object != null) {
+                return object;
+            }
+        }
+        return null;
+    }
+
+}

src/main/java/com/rometools/utils/Dates.java

@@ -0,0 +1,38 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import java.util.Date;
+
+public final class Dates {
+
+    private Dates() {
+    }
+
+    /**
+     * Creates a copy on a Date.
+     *
+     * @param d The Date to copy, can be null
+     * @return null when the input Date was null, a copy of the Date otherwise
+     */
+    public static Date copy(final Date d) {
+        if (d == null) {
+            return null;
+        } else {
+            return new Date(d.getTime());
+        }
+    }
+
+}

src/main/java/com/rometools/utils/Doubles.java

@@ -0,0 +1,39 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+public class Doubles {
+
+    private Doubles() {
+    }
+
+    /**
+     * Converts a String into an Double.
+     *
+     * @param s The String to convert, may be null
+     * @return The parsed Double or null when parsing is not possible
+     */
+    public static Double parse(final String s) {
+        Double parsed = null;
+        try {
+            if (s != null) {
+                parsed = Double.parseDouble(s);
+            }
+        } catch (final NumberFormatException e) {
+        }
+        return parsed;
+    }
+
+}

src/main/java/com/rometools/utils/IO.java

@@ -0,0 +1,63 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import java.io.Closeable;
+import java.io.IOException;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Utility class to handle I/O operations.
+ *
+ * @author Patrick Gotthard
+ *
+ */
+public final class IO {
+
+    private static final Logger LOG = LoggerFactory.getLogger(IO.class);
+
+    private IO() {
+    }
+
+    /**
+     * Closes a {@link Closeable} object without suppressing a possible {@link IOException}.
+     *
+     * @param closeable The {@link Closeable} to close
+     * @throws IOException when the {@link Closeable} can't be closed
+     */
+    public static void close(final Closeable closeable) throws IOException {
+        if (closeable != null) {
+            closeable.close();
+        }
+    }
+
+    /**
+     * Closes a {@link Closeable} object and suppresses a possible {@link IOException}.
+     *
+     * @param closeable The {@link Closeable} to close
+     */
+    public static void closeQuietly(final Closeable closeable) {
+        if (closeable != null) {
+            try {
+                closeable.close();
+            } catch (final IOException e) {
+                LOG.warn("Unable to close resource", e);
+            }
+        }
+    }
+
+}

src/main/java/com/rometools/utils/Integers.java

@@ -0,0 +1,36 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+public final class Integers {
+
+    private Integers() {
+    }
+
+    /**
+     * Converts a String into an Integer.
+     *
+     * @param s The String to convert, may be null
+     * @return The parsed Integer or null when parsing is not possible
+     */
+    public static Integer parse(final String s) {
+        try {
+            return Integer.parseInt(s);
+        } catch (final NumberFormatException e) {
+            return null;
+        }
+    }
+
+}

src/main/java/com/rometools/utils/Lists.java

@@ -0,0 +1,116 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public final class Lists {
+
+    private Lists() {
+    }
+
+    /**
+     * Returns the list when it is not null. Returns a new list otherwise.
+     *
+     * @param list The list to process, can be null
+     * @return The input list when it is not null, a new list otherwise
+     */
+    public static <T> List<T> createWhenNull(final List<T> list) {
+        if (list == null) {
+            return new ArrayList<T>();
+        } else {
+            return list;
+        }
+    }
+
+    /**
+     * Creates a new List with the given item as the first entry.
+     *
+     * @param item The item to add to the new list
+     * @return List containing the given item
+     */
+    public static <T> List<T> create(final T item) {
+        final List<T> list = new ArrayList<T>();
+        list.add(item);
+        return list;
+    }
+
+    /**
+     * Extracts the first entry of the list when it is not null and contains values.
+     *
+     * @param list The list to extract the first entry from, can be null
+     * @return The first entry of the list when it is not null or empty, null otherwise
+     */
+    public static <T> T firstEntry(final List<T> list) {
+        if (list != null && !list.isEmpty()) {
+            return list.get(0);
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Checks whether the list is null or empty.
+     *
+     * @param list The list to check
+     * @return true when the list is null or empty, false otherwise
+     */
+    public static boolean isEmpty(final List<?> list) {
+        return list == null || list.isEmpty();
+    }
+
+    /**
+     * Checks whether the list is not null and not empty.
+     *
+     * @param list The list to check
+     * @return true when the list is not null and not empty
+     */
+    public static boolean isNotEmpty(final List<?> list) {
+        return !isEmpty(list);
+    }
+
+    /**
+     * Checks whether the list has the given size. A null list is treated like a list without
+     * entries.
+     *
+     * @param list The list to check
+     * @param size The size to check
+     * @return true when the list has the given size or when size = 0 and the list is null, false
+     *         otherwise
+     */
+    public static boolean sizeIs(final List<?> list, final int size) {
+        if (size == 0) {
+            return list == null || list.isEmpty();
+        } else {
+            return list != null && list.size() == size;
+        }
+    }
+
+    /**
+     * Returns null, when the given list is empty or null
+     *
+     * @param list The list to process
+     * @return null when the list is empty or null, the given list otherwise
+     */
+    public static <T> List<T> emptyToNull(final List<T> list) {
+        if (isEmpty(list)) {
+            return null;
+        } else {
+            return list;
+        }
+    }
+
+}

src/main/java/com/rometools/utils/Longs.java

@@ -0,0 +1,39 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+public final class Longs {
+
+    private Longs() {
+    }
+
+    /**
+     * Converts a String into a Long by first parsing it as Double and then casting it to Long.
+     *
+     * @param s The String to convert, may be null or in decimal format
+     * @return The parsed Long or null when parsing is not possible
+     */
+    public static Long parseDecimal(final String s) {
+        Long parsed = null;
+        try {
+            if (s != null) {
+                parsed = (long) Double.parseDouble(s);
+            }
+        } catch (final NumberFormatException e) {
+        }
+        return parsed;
+    }
+
+}

src/main/java/com/rometools/utils/Strings.java

@@ -0,0 +1,126 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import java.util.Locale;
+
+public final class Strings {
+
+    private Strings() {
+    }
+
+    /**
+     * Checks whether a String is null.
+     *
+     * @param s The String to check
+     * @return true when the String is null, false otherwise
+     */
+    public static boolean isNull(final String s) {
+        return s == null;
+    }
+
+    /**
+     * Checks whether a String is null or empty.
+     *
+     * @param s The String to check
+     * @return true when the String is null or empty, false otherwise
+     */
+    public static boolean isEmpty(final String s) {
+        return isNull(s) || s.isEmpty();
+    }
+
+    /**
+     * Checks whether a String is neither null nor empty.
+     *
+     * @param s The String to check
+     * @return true when the String is neither null nor empty, false otherwise
+     */
+    public static boolean isNotEmpty(final String s) {
+        return !isEmpty(s);
+    }
+
+    /**
+     * Checks whether a String is null, empty or blank.
+     *
+     * @param s The String to check
+     * @return true when the String is null, empty or blank, false otherwise
+     */
+    public static boolean isBlank(final String s) {
+        return isEmpty(s) || s.trim().isEmpty();
+    }
+
+    /**
+     * Removes the whitespace at the beginning and end of a String.
+     *
+     * @param s The String to trim, may be null
+     * @return null when the input String is null, the trimmed String otherwise
+     */
+    public static String trim(final String s) {
+        if (s == null) {
+            return null;
+        } else {
+            return s.trim();
+        }
+    }
+
+    /**
+     * Removes the whitespace at the beginning and end of a String. When the String only contains
+     * whitespace, it returns null.
+     *
+     * @param s The String to trim, may be null
+     * @return null when the input String is null or does only contain whitespace, the trimmed
+     *         String otherwise
+     */
+    public static String trimToNull(final String s) {
+        final String trimmed = trim(s);
+        if (trimmed == null || trimmed.isEmpty()) {
+            return null;
+        } else {
+            return trimmed;
+        }
+    }
+
+    /**
+     * Removes the whitespace at the beginning and end of a String. When the String only contains
+     * whitespace, it returns null.
+     *
+     * @param s The String to trim, may be null
+     * @return null when the input String is null or does only contain whitespace, the trimmed
+     *         String otherwise
+     */
+    public static String trimToEmpty(final String s) {
+        final String trimmed = trim(s);
+        if (trimmed == null || trimmed.isEmpty()) {
+            return "";
+        } else {
+            return trimmed;
+        }
+    }
+
+    /**
+     * null-safe lower-case conversion of a String.
+     *
+     * @param s The String to process, may be null
+     * @return null when the input String is null, the String in lower-case otherwise
+     */
+    public static String toLowerCase(final String s) {
+        if (s == null) {
+            return null;
+        } else {
+            return s.toLowerCase(Locale.ENGLISH);
+        }
+    }
+
+}

src/test/java/com/rometools/utils/AlternativesTest.java

@@ -0,0 +1,37 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
+import static org.junit.Assert.assertThat;
+
+import org.junit.Test;
+
+public class AlternativesTest {
+
+    @Test
+    public void testFirstNotNull() {
+
+        final Integer nullInteger = null;
+        final Integer notNullInteger = 1;
+
+        assertThat(Alternatives.firstNotNull(notNullInteger, nullInteger), is(notNullInteger));
+        assertThat(Alternatives.firstNotNull(nullInteger, notNullInteger), is(notNullInteger));
+        assertThat(Alternatives.firstNotNull(nullInteger, nullInteger), is(nullValue()));
+
+    }
+
+}

src/test/java/com/rometools/utils/DatesTest.java

@@ -0,0 +1,40 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.hamcrest.Matchers.nullValue;
+import static org.junit.Assert.assertThat;
+
+import java.util.Date;
+
+import org.junit.Test;
+
+public class DatesTest {
+
+    @Test
+    public void testCopy() {
+
+        final Date date = new Date();
+        final Date nullDate = null;
+
+        assertThat(Dates.copy(date), is(notNullValue()));
+        assertThat(Dates.copy(date).getTime(), is(date.getTime()));
+        assertThat(Dates.copy(nullDate), is(nullValue()));
+
+    }
+
+}

src/test/java/com/rometools/utils/DoublesTest.java

@@ -0,0 +1,40 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
+
+import org.junit.Test;
+
+public class DoublesTest {
+
+    @Test
+    public void testParse() {
+
+        final String nullString = null;
+        final String emptyString = null;
+        final String integerString = "1";
+        final String decimalString = "1.0";
+
+        assertThat(Doubles.parse(nullString), is(nullValue()));
+        assertThat(Doubles.parse(emptyString), is(nullValue()));
+        assertThat(Doubles.parse(integerString), is(1.0));
+        assertThat(Doubles.parse(decimalString), is(1.0));
+
+    }
+
+}

src/test/java/com/rometools/utils/IntegersTest.java

@@ -0,0 +1,40 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
+
+import org.junit.Test;
+
+public class IntegersTest {
+
+    @Test
+    public void testParse() {
+
+        final String nullString = null;
+        final String emptyString = null;
+        final String integerString = "1";
+        final String decimalString = "1.0";
+
+        assertThat(Integers.parse(nullString), is(nullValue()));
+        assertThat(Integers.parse(emptyString), is(nullValue()));
+        assertThat(Integers.parse(integerString), is(1));
+        assertThat(Integers.parse(decimalString), is(nullValue()));
+
+    }
+
+}

src/test/java/com/rometools/utils/ListsTest.java

@@ -0,0 +1,119 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import static org.hamcrest.Matchers.hasItem;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.hamcrest.Matchers.nullValue;
+import static org.junit.Assert.assertThat;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.Test;
+
+public class ListsTest {
+
+    @Test
+    public void testCreateWhenNull() {
+
+        final List<Integer> list = new ArrayList<Integer>();
+        final List<Integer> nullList = null;
+
+        assertThat(Lists.createWhenNull(list), is(notNullValue()));
+        assertThat(Lists.createWhenNull(list), is(list));
+        assertThat(Lists.createWhenNull(nullList), is(notNullValue()));
+
+    }
+
+    @Test
+    public void testCreate() {
+
+        final List<Integer> create = Lists.create(1);
+        assertThat(create, is(notNullValue()));
+        assertThat(create.size(), is(1));
+        assertThat(create, hasItem(1));
+
+    }
+
+    @Test
+    public void testFirstEntry() {
+
+        final List<Integer> nullList = null;
+        final List<Integer> listWithoutEntries = new ArrayList<Integer>();
+        final List<Integer> listWithOneEntry = Arrays.asList(1);
+        final List<Integer> listWithTwoEntries = Arrays.asList(1, 2);
+
+        assertThat(Lists.firstEntry(nullList), is(nullValue()));
+        assertThat(Lists.firstEntry(listWithoutEntries), is(nullValue()));
+        assertThat(Lists.firstEntry(listWithOneEntry), is(1));
+        assertThat(Lists.firstEntry(listWithTwoEntries), is(1));
+
+    }
+
+    @Test
+    public void testIsEmpty() {
+
+        final List<Integer> nullList = null;
+        final List<Integer> listWithoutEntries = new ArrayList<Integer>();
+        final List<Integer> listWithOneEntry = Arrays.asList(1);
+
+        assertThat(Lists.isEmpty(nullList), is(true));
+        assertThat(Lists.isEmpty(listWithoutEntries), is(true));
+        assertThat(Lists.isEmpty(listWithOneEntry), is(false));
+
+    }
+
+    @Test
+    public void testIsNotEmpty() {
+
+        final List<Integer> nullList = null;
+        final List<Integer> listWithoutEntries = new ArrayList<Integer>();
+        final List<Integer> listWithOneEntry = Arrays.asList(1);
+
+        assertThat(Lists.isNotEmpty(nullList), is(false));
+        assertThat(Lists.isNotEmpty(listWithoutEntries), is(false));
+        assertThat(Lists.isNotEmpty(listWithOneEntry), is(true));
+    }
+
+    @Test
+    public void testSizeIs() {
+
+        final List<Integer> nullList = null;
+        final List<Integer> listWithoutEntries = new ArrayList<Integer>();
+        final List<Integer> listWithOneEntry = Arrays.asList(1);
+
+        assertThat(Lists.sizeIs(nullList, 0), is(true));
+        assertThat(Lists.sizeIs(listWithoutEntries, 0), is(true));
+        assertThat(Lists.sizeIs(listWithOneEntry, 1), is(true));
+
+    }
+
+    @Test
+    public void testEmptyToNull() {
+
+        final List<Integer> nullList = null;
+        final List<Integer> listWithoutEntries = new ArrayList<Integer>();
+        final List<Integer> listWithOneEntry = Arrays.asList(1);
+
+        assertThat(Lists.emptyToNull(nullList), is(nullValue()));
+        assertThat(Lists.emptyToNull(listWithoutEntries), is(nullValue()));
+        assertThat(Lists.emptyToNull(listWithOneEntry), is(notNullValue()));
+
+    }
+
+}

src/test/java/com/rometools/utils/LongsTest.java

@@ -0,0 +1,40 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
+
+import org.junit.Test;
+
+public class LongsTest {
+
+    @Test
+    public void testParseDecimal() {
+
+        final String nullString = null;
+        final String emptyString = "";
+        final String longString = String.valueOf(Long.MAX_VALUE);
+        final String decimalString = String.valueOf(Double.MAX_VALUE);
+
+        assertThat(Longs.parseDecimal(nullString), is(nullValue()));
+        assertThat(Longs.parseDecimal(emptyString), is(nullValue()));
+        assertThat(Longs.parseDecimal(longString), is(Long.MAX_VALUE));
+        assertThat(Longs.parseDecimal(decimalString), is((long) Double.MAX_VALUE));
+
+    }
+
+}

src/test/java/com/rometools/utils/StringsTest.java

@@ -0,0 +1,139 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.rometools.utils;
+
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
+import static org.junit.Assert.assertThat;
+
+import org.junit.Test;
+
+public class StringsTest {
+
+    @Test
+    public void testIsNull() {
+
+        final String nullString = null;
+        final String emptyString = "";
+        final String blankString = " ";
+        final String string = "a";
+
+        assertThat(Strings.isNull(nullString), is(true));
+        assertThat(Strings.isNull(emptyString), is(false));
+        assertThat(Strings.isNull(blankString), is(false));
+        assertThat(Strings.isNull(string), is(false));
+
+    }
+
+    @Test
+    public void testIsEmpty() {
+
+        final String nullString = null;
+        final String emptyString = "";
+        final String blankString = " ";
+        final String string = "a";
+
+        assertThat(Strings.isEmpty(nullString), is(true));
+        assertThat(Strings.isEmpty(emptyString), is(true));
+        assertThat(Strings.isEmpty(blankString), is(false));
+        assertThat(Strings.isEmpty(string), is(false));
+
+    }
+
+    @Test
+    public void testIsNotEmpty() {
+
+        final String nullString = null;
+        final String emptyString = "";
+        final String blankString = " ";
+        final String string = "a";
+
+        assertThat(Strings.isNotEmpty(nullString), is(false));
+        assertThat(Strings.isNotEmpty(emptyString), is(false));
+        assertThat(Strings.isNotEmpty(blankString), is(true));
+        assertThat(Strings.isNotEmpty(string), is(true));
+    }
+
+    @Test
+    public void testIsBlank() {
+
+        final String nullString = null;
+        final String emptyString = "";
+        final String blankString = " ";
+        final String string = "a";
+
+        assertThat(Strings.isBlank(nullString), is(true));
+        assertThat(Strings.isBlank(emptyString), is(true));
+        assertThat(Strings.isBlank(blankString), is(true));
+        assertThat(Strings.isBlank(string), is(false));
+    }
+
+    @Test
+    public void testTrim() {
+
+        final String nullString = null;
+        final String emptyString = "";
+        final String blankString = " ";
+        final String string = " a ";
+
+        assertThat(Strings.trim(nullString), is(nullValue()));
+        assertThat(Strings.trim(emptyString), is(""));
+        assertThat(Strings.trim(blankString), is(""));
+        assertThat(Strings.trim(string), is("a"));
+    }
+
+    @Test
+    public void testTrimToEmpty() {
+
+        final String nullString = null;
+        final String emptyString = "";
+        final String blankString = " ";
+        final String string = " a ";
+
+        assertThat(Strings.trimToEmpty(nullString), is(""));
+        assertThat(Strings.trimToEmpty(emptyString), is(""));
+        assertThat(Strings.trimToEmpty(blankString), is(""));
+        assertThat(Strings.trimToEmpty(string), is("a"));
+    }
+
+    @Test
+    public void testTrimToNull() {
+
+        final String nullString = null;
+        final String emptyString = "";
+        final String blankString = " ";
+        final String string = " a ";
+
+        assertThat(Strings.trimToNull(nullString), is(nullValue()));
+        assertThat(Strings.trimToNull(emptyString), is(nullValue()));
+        assertThat(Strings.trimToNull(blankString), is(nullValue()));
+        assertThat(Strings.trimToNull(string), is("a"));
+    }
+
+    @Test
+    public void testToLowerCase() {
+
+        final String nullString = null;
+        final String emptyString = "";
+        final String blankString = " ";
+        final String string = "A";
+
+        assertThat(Strings.toLowerCase(nullString), is(nullValue()));
+        assertThat(Strings.toLowerCase(emptyString), is(""));
+        assertThat(Strings.toLowerCase(blankString), is(" "));
+        assertThat(Strings.toLowerCase(string), is("a"));
+    }
+
+}