Explicitly check arguments for null

(Not using Objects.requireNonNull because it's not available on older
Android.)

Author: robinst

src/main/java/org/nibor/autolink/Autolink.java

@@ -9,12 +9,21 @@ public class Autolink {
      * Render the supplied links from the supplied input text using a renderer. The parts of the text outside of links
      * are added to the result without processing.
      *
-     * @param input the input text
+     * @param input the input text, must not be null
      * @param links the links to render, see {@link LinkExtractor} to extract them
      * @param linkRenderer the link rendering implementation
      * @return the rendered string
      */
     public static String renderLinks(CharSequence input, Iterable<LinkSpan> links, LinkRenderer linkRenderer) {
+        if (input == null) {
+            throw new NullPointerException("input must not be null");
+        }
+        if (links == null) {
+            throw new NullPointerException("links must not be null");
+        }
+        if (linkRenderer == null) {
+            throw new NullPointerException("linkRenderer must not be null");
+        }
         StringBuilder sb = new StringBuilder(input.length() + 16);
         int lastIndex = 0;
         for (LinkSpan link : links) {

src/main/java/org/nibor/autolink/LinkExtractor.java

@@ -31,10 +31,13 @@ public static Builder builder() {
     /**
      * Extract the links from the input text. Can be called multiple times with different inputs (thread-safe).
      *
-     * @param input the input text, must not be {@code null}
-     * @return a lazy iterable for the links in order that they appear in the input, never {@code null}
+     * @param input the input text, must not be null
+     * @return a lazy iterable for the links in order that they appear in the input, never null
      */
     public Iterable<LinkSpan> extractLinks(final CharSequence input) {
+        if (input == null) {
+            throw new NullPointerException("input must not be null");
+        }
         return new Iterable<LinkSpan>() {
             @Override
             public Iterator<LinkSpan> iterator() {