Apply some IDE suggestions, JavaDoc and GitHub PR

Update assertion-message
Adjust JavaDoc
Add tests
Reformat class DirectoryNode, adjust/move some comments

Closes #730

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1921980 13f79535-47bb-0310-9956-ffa450edef68

poi-ooxml/src/main/java/org/apache/poi/poifs/crypt/dsig/SignatureConfig.java

@@ -26,7 +26,6 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import java.security.KeyStore;
 import java.security.KeyStoreException;
 import java.security.PrivateKey;
-import java.security.Provider;
 import java.security.cert.Certificate;
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
@@ -52,14 +51,11 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import javax.xml.crypto.dsig.CanonicalizationMethod;
 import javax.xml.crypto.dsig.DigestMethod;
 import javax.xml.crypto.dsig.Transform;
-import javax.xml.crypto.dsig.XMLSignatureFactory;
-import javax.xml.crypto.dsig.keyinfo.KeyInfoFactory;
 
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.poi.EncryptedDocumentException;
 import org.apache.poi.hpsf.ClassID;
-import org.apache.poi.openxml4j.opc.OPCPackage;
 import org.apache.poi.poifs.crypt.HashAlgorithm;
 import org.apache.poi.poifs.crypt.dsig.facets.KeyInfoSignatureFacet;
 import org.apache.poi.poifs.crypt.dsig.facets.OOXMLSignatureFacet;
@@ -73,7 +69,6 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import org.apache.poi.poifs.crypt.dsig.services.TimeStampService;
 import org.apache.poi.poifs.crypt.dsig.services.TimeStampServiceValidator;
 import org.apache.poi.poifs.crypt.dsig.services.TimeStampSimpleHttpClient;
-import org.apache.poi.util.Internal;
 import org.apache.poi.util.LocaleUtil;
 import org.apache.poi.util.Removal;
 import org.apache.xml.security.signature.XMLSignature;
@@ -382,7 +377,7 @@ public String formatExecutionTime() {
      * @since POI 4.0.0
      */
     public void setExecutionTime(String executionTime) {
-        if (executionTime != null && !"".equals(executionTime)){
+        if (executionTime != null && !executionTime.isEmpty()){
             final DateFormat fmt = new SimpleDateFormat(SIGNATURE_TIME_FORMAT, Locale.ROOT);
             fmt.setTimeZone(LocaleUtil.TIMEZONE_UTC);
             try {
@@ -992,12 +987,12 @@ public void setSignatureMethodFromUri(final String signatureMethodUri) {
      * <li>the JDK xmlsec provider</li>
      * </ol>
      *
-     * @return a list of possible XMLSEC provider class names
+     * @return an array of possible XMLSEC provider class names
      */
     public static String[] getProviderNames() {
         // need to check every time, as the system property might have been changed in the meantime
         String sysProp = System.getProperty("jsr105Provider");
-        return (sysProp == null || "".equals(sysProp))
+        return (sysProp == null || sysProp.isEmpty())
             ? new String[]{XMLSEC_SANTUARIO, XMLSEC_JDK}
             : new String[]{sysProp, XMLSEC_SANTUARIO, XMLSEC_JDK};
     }
@@ -1031,7 +1026,7 @@ public boolean isUpdateConfigOnValidate() {
 
     /**
      * The signature config can be updated if a document is succesful validated.
-     * This flag is used for activating this modifications.
+     * This flag is used for activating these modifications.
      * Defaults to {@code false}
      *
      * @param updateConfigOnValidate if true, update config on validate

poi-ooxml/src/test/java/org/apache/poi/xslf/usermodel/TestXSLFTextParagraph.java

@@ -19,6 +19,7 @@ Licensed to the Apache Software Foundation (ASF) under one or more
 import static org.apache.poi.sl.usermodel.BaseTestSlideShow.getColor;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -467,21 +468,21 @@ public void drawString(AttributedCharacterIterator iterator, float x, float y) {
                         attributes = iterator.getAttributes();
                     }
 
-                    if ("This is a".equals(sb.toString())) {
+                    if ("This is a".contentEquals(sb)) {
                         // Should be no background.
                         assertNotNull(attributes);
                         Object background = attributes.get(TextAttribute.BACKGROUND);
                         assertNull(background);
                     }
-                    if ("highlight".equals(sb.toString())) {
+                    if ("highlight".contentEquals(sb)) {
                         // Should be yellow background.
                         assertNotNull(attributes);
                         Object background = attributes.get(TextAttribute.BACKGROUND);
                         assertNotNull(background);
-                        assertTrue(background instanceof Color);
+                        assertInstanceOf(Color.class, background);
                         assertEquals(Color.yellow, background);
                     }
-                    if (" test".equals(sb.toString())) {
+                    if (" test".contentEquals(sb)) {
                         // Should be no background.
                         assertNotNull(attributes);
                         Object background = attributes.get(TextAttribute.BACKGROUND);
@@ -494,5 +495,4 @@ public void drawString(AttributedCharacterIterator iterator, float x, float y) {
             ppt.getSlides().get(0).draw(dgfx);
         }
     }
-
 }

poi-ooxml/src/test/java/org/apache/poi/xssf/usermodel/TestXSSFBugs.java

@@ -3331,7 +3331,7 @@ void test58896WithFile() throws IOException {
             LOG.atInfo().log(between(start, now()));
 
             assertTrue(between(start, now()).getSeconds() < 25,
-                    "Had start: " + start + ", now: " + now() +
+                    "Expected to have less than 25s duration for test, but had start: " + start + ", now: " + now() +
                             ", diff: " + Duration.between(start, now()).getSeconds());
         }
     }

poi-scratchpad/src/main/java/org/apache/poi/hsmf/datatypes/PropertiesChunk.java

@@ -447,8 +447,9 @@ private void writeFixedLengthValueHeader(OutputStream out, MAPIProperty property
     /**
      * Writes out pre-calculated raw values which assume any variable length property `data`
      *  field to already have size, reserved and manually written header
-     * @param out
-     * @throws IOException
+     *
+     * @param out The OutputStream to write the data to
+     * @throws IOException If an I/O error occurs while writing data
      */
     private void writeVariableLengthPreCalculatedValue(OutputStream out, PropertyValue value) throws IOException {
         // variable length header

poi-scratchpad/src/main/java/org/apache/poi/hwpf/HWPFDocument.java

@@ -291,7 +291,7 @@ public HWPFDocument(DirectoryNode directory) throws IOException {
         _text = _tpt.getText();
 
         /*
-         * in this mode we preserving PAPX/CHPX structure from file, so text may
+         * in this mode we are preserving PAPX/CHPX structure from file, so text may
          * miss from output, and text order may be corrupted
          */
         boolean preserveBinTables = false;

poi/src/main/java/org/apache/poi/hssf/record/RecordFactory.java

@@ -173,7 +173,7 @@ public static short[] getAllKnownRecordSIDs() {
      *
      * @param in the InputStream from which the records will be obtained
      *
-     * @return an array of Records created from the InputStream
+     * @return a list of Records created from the InputStream
      *
      * @throws org.apache.poi.util.RecordFormatException on error processing the InputStream
      */