PDFBOX-5660: avoid NPE, as suggested by Valery Bokov

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1929807 13f79535-47bb-0310-9956-ffa450edef68

Author: THausherr

pdfbox/src/main/java/org/apache/pdfbox/pdmodel/interactive/annotation/handlers/PDLineAppearanceHandler.java

@@ -169,7 +169,7 @@ public void generateNormalAppearance()
                 float contentLength = 0;
                 try
                 {
-                    contentLength = font.getStringWidth(annotation.getContents()) / 1000 * FONT_SIZE;
+                    contentLength = font.getStringWidth(contents) / 1000 * FONT_SIZE;
 
                     //TODO How to decide the size of the font?
                     // 9 seems to be standard, but if the text doesn't fit, a scaling is done
@@ -178,7 +178,7 @@ public void generateNormalAppearance()
                 catch (IllegalArgumentException ex)
                 {
                     // Adobe Reader displays placeholders instead
-                    LOG.error(() -> "line text '" + annotation.getContents() + "' can't be shown", ex);
+                    LOG.error("line text '" + contents + "' can't be shown", ex);
                 }
                 float xOffset = (lineLength - contentLength) / 2;
                 float yOffset;
@@ -230,7 +230,7 @@ public void generateNormalAppearance()
                     cs.setFont(font, FONT_SIZE);
                     cs.newLineAtOffset(xOffset + captionHorizontalOffset, 
                                        y + yOffset + captionVerticalOffset);
-                    cs.showText(annotation.getContents());
+                    cs.showText(contents);
                     cs.endText();
                 }