[github-278] Resolve all SpotBugs P1 issues in Main and Test. Thanks to Andreas Reichel. This closes #278

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1895016 13f79535-47bb-0310-9956-ffa450edef68

12 files changed, 39 insertions, 43 deletions

diff --git a/poi/src/main/java/org/apache/poi/poifs/crypt/Encryptor.java b/poi/src/main/java/org/apache/poi/poifs/crypt/Encryptor.java
index d6af6d44f7..0e2581a64e 100644
--- a/poi/src/main/java/org/apache/poi/poifs/crypt/Encryptor.java
+++ b/poi/src/main/java/org/apache/poi/poifs/crypt/Encryptor.java
@@ -31,6 +31,7 @@ import org.apache.poi.poifs.filesystem.POIFSFileSystem;
 import org.apache.poi.util.GenericRecordUtil;
 
 public abstract class Encryptor implements GenericRecord {
+
     protected static final String DEFAULT_POIFS_ENTRY = Decryptor.DEFAULT_POIFS_ENTRY;
     private EncryptionInfo encryptionInfo;
     private SecretKey secretKey;
diff --git a/poi/src/main/java/org/apache/poi/poifs/crypt/agile/AgileEncryptor.java b/poi/src/main/java/org/apache/poi/poifs/crypt/agile/AgileEncryptor.java
index 4df5540517..455959451e 100644
--- a/poi/src/main/java/org/apache/poi/poifs/crypt/agile/AgileEncryptor.java
+++ b/poi/src/main/java/org/apache/poi/poifs/crypt/agile/AgileEncryptor.java
@@ -37,8 +37,6 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.security.GeneralSecurityException;
 import java.security.MessageDigest;
-import java.security.SecureRandom;
-import java.util.Random;
 
 import javax.crypto.Cipher;
 import javax.crypto.Mac;
@@ -62,6 +60,7 @@ import org.apache.poi.util.IOUtils;
 import org.apache.poi.util.LittleEndian;
 import org.apache.poi.util.LittleEndianByteArrayOutputStream;
 import org.apache.poi.util.LittleEndianConsts;
+import org.apache.poi.util.RandomSingleton;
 import org.apache.poi.util.XMLHelper;
 import org.w3c.dom.Document;
 
@@ -81,7 +80,6 @@ public class AgileEncryptor extends Encryptor {
     @Override
     public void confirmPassword(String password) {
         // see [MS-OFFCRYPTO] - 2.3.3 EncryptionVerifier
-        Random r = new SecureRandom();
         AgileEncryptionHeader header = (AgileEncryptionHeader)getEncryptionInfo().getHeader();
         int blockSize = header.getBlockSize();
         int keySize = header.getKeySize()/8;
@@ -93,11 +91,13 @@ public class AgileEncryptor extends Encryptor {
              , newKeySalt = IOUtils.safelyAllocate(blockSize, maxLen)
              , newKeySpec = IOUtils.safelyAllocate(keySize, maxLen)
              , newIntegritySalt = IOUtils.safelyAllocate(hashSize, maxLen);
-        r.nextBytes(newVerifierSalt); // blocksize
-        r.nextBytes(newVerifier); // blocksize
-        r.nextBytes(newKeySalt); // blocksize
-        r.nextBytes(newKeySpec); // keysize
-        r.nextBytes(newIntegritySalt); // hashsize
+
+        // using a java.security.SecureRandom (and avoid allocating a new SecureRandom for each random number needed).
+        RandomSingleton.getInstance().nextBytes(newVerifierSalt); // blocksize
+        RandomSingleton.getInstance().nextBytes(newVerifier); // blocksize
+        RandomSingleton.getInstance().nextBytes(newKeySalt); // blocksize
+        RandomSingleton.getInstance().nextBytes(newKeySpec); // keysize
+        RandomSingleton.getInstance().nextBytes(newIntegritySalt); // hashsize
 
         confirmPassword(password, newKeySpec, newKeySalt, newVerifierSalt, newVerifier, newIntegritySalt);
     }
diff --git a/poi/src/main/java/org/apache/poi/poifs/crypt/binaryrc4/BinaryRC4Encryptor.java b/poi/src/main/java/org/apache/poi/poifs/crypt/binaryrc4/BinaryRC4Encryptor.java
index c048271421..9b4542ab0b 100644
--- a/poi/src/main/java/org/apache/poi/poifs/crypt/binaryrc4/BinaryRC4Encryptor.java
+++ b/poi/src/main/java/org/apache/poi/poifs/crypt/binaryrc4/BinaryRC4Encryptor.java
@@ -22,8 +22,6 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.security.GeneralSecurityException;
 import java.security.MessageDigest;
-import java.security.SecureRandom;
-import java.util.Random;
 
 import javax.crypto.Cipher;
 import javax.crypto.SecretKey;
@@ -38,6 +36,7 @@ import org.apache.poi.poifs.crypt.HashAlgorithm;
 import org.apache.poi.poifs.crypt.standard.EncryptionRecord;
 import org.apache.poi.poifs.filesystem.DirectoryNode;
 import org.apache.poi.util.LittleEndianByteArrayOutputStream;
+import org.apache.poi.util.RandomSingleton;
 
 public class BinaryRC4Encryptor extends Encryptor {
 
@@ -52,11 +51,12 @@ public class BinaryRC4Encryptor extends Encryptor {
 
     @Override
     public void confirmPassword(String password) {
-        Random r = new SecureRandom();
         byte[] salt = new byte[16];
         byte[] verifier = new byte[16];
-        r.nextBytes(salt);
-        r.nextBytes(verifier);
+
+        // using a java.security.SecureRandom (and avoid allocating a new SecureRandom for each random number needed).
+        RandomSingleton.getInstance().nextBytes(salt);
+        RandomSingleton.getInstance().nextBytes(verifier);
         confirmPassword(password, null, null, verifier, salt, null);
     }
 
diff --git a/poi/src/main/java/org/apache/poi/poifs/crypt/cryptoapi/CryptoAPIEncryptor.java b/poi/src/main/java/org/apache/poi/poifs/crypt/cryptoapi/CryptoAPIEncryptor.java
index 176f431eec..f44ec7a7be 100644
--- a/poi/src/main/java/org/apache/poi/poifs/crypt/cryptoapi/CryptoAPIEncryptor.java
+++ b/poi/src/main/java/org/apache/poi/poifs/crypt/cryptoapi/CryptoAPIEncryptor.java
@@ -22,10 +22,8 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.security.GeneralSecurityException;
 import java.security.MessageDigest;
-import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Random;
 
 import javax.crypto.Cipher;
 import javax.crypto.SecretKey;
@@ -43,6 +41,7 @@ import org.apache.poi.poifs.filesystem.Entry;
 import org.apache.poi.poifs.filesystem.POIFSFileSystem;
 import org.apache.poi.util.IOUtils;
 import org.apache.poi.util.LittleEndian;
+import org.apache.poi.util.RandomSingleton;
 import org.apache.poi.util.StringUtil;
 
 public class CryptoAPIEncryptor extends Encryptor {
@@ -58,11 +57,11 @@ public class CryptoAPIEncryptor extends Encryptor {
 
     @Override
     public void confirmPassword(String password) {
-        Random r = new SecureRandom();
         byte[] salt = new byte[16];
         byte[] verifier = new byte[16];
-        r.nextBytes(salt);
-        r.nextBytes(verifier);
+        // using a java.security.SecureRandom (and avoid allocating a new SecureRandom for each random number needed).
+        RandomSingleton.getInstance().nextBytes(salt);
+        RandomSingleton.getInstance().nextBytes(verifier);
         confirmPassword(password, null, null, verifier, salt, null);
     }
 
diff --git a/poi/src/main/java/org/apache/poi/poifs/crypt/standard/StandardEncryptor.java b/poi/src/main/java/org/apache/poi/poifs/crypt/standard/StandardEncryptor.java
index 097a7bd6d7..c5f931c62a 100644
--- a/poi/src/main/java/org/apache/poi/poifs/crypt/standard/StandardEncryptor.java
+++ b/poi/src/main/java/org/apache/poi/poifs/crypt/standard/StandardEncryptor.java
@@ -28,9 +28,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.security.GeneralSecurityException;
 import java.security.MessageDigest;
-import java.security.SecureRandom;
 import java.util.Arrays;
-import java.util.Random;
 
 import javax.crypto.Cipher;
 import javax.crypto.CipherOutputStream;
@@ -51,6 +49,7 @@ import org.apache.poi.util.IOUtils;
 import org.apache.poi.util.LittleEndianByteArrayOutputStream;
 import org.apache.poi.util.LittleEndianConsts;
 import org.apache.poi.util.LittleEndianOutputStream;
+import org.apache.poi.util.RandomSingleton;
 import org.apache.poi.util.TempFile;
 
 public class StandardEncryptor extends Encryptor {
@@ -65,10 +64,11 @@ public class StandardEncryptor extends Encryptor {
     @Override
     public void confirmPassword(String password) {
         // see [MS-OFFCRYPTO] - 2.3.3 EncryptionVerifier
-        Random r = new SecureRandom();
         byte[] salt = new byte[16], verifier = new byte[16];
-        r.nextBytes(salt);
-        r.nextBytes(verifier);
+
+        // using a java.security.SecureRandom (and avoid allocating a new SecureRandom for each random number needed).
+        RandomSingleton.getInstance().nextBytes(salt);
+        RandomSingleton.getInstance().nextBytes(verifier);
 
         confirmPassword(password, null, null, salt, verifier, null);
     }
diff --git a/poi/src/main/java/org/apache/poi/ss/util/CellUtil.java b/poi/src/main/java/org/apache/poi/ss/util/CellUtil.java
index 283d7d4de7..99d92c4750 100644
--- a/poi/src/main/java/org/apache/poi/ss/util/CellUtil.java
+++ b/poi/src/main/java/org/apache/poi/ss/util/CellUtil.java
@@ -244,7 +244,7 @@ public final class CellUtil {
         // Copy CellStyle
         if (policy.isCopyCellStyle()) {
             if (destCell.getSheet().getWorkbook() == srcCell.getSheet().getWorkbook()) {
-                destCell.setCellStyle(srcCell == null ? null : srcCell.getCellStyle());
+                destCell.setCellStyle(srcCell.getCellStyle());
             } else {
                 CellStyle srcStyle = srcCell.getCellStyle();
                 CellStyle destStyle = context == null ? null : context.getMappedStyle(srcStyle);
diff --git a/poi/src/main/java/org/apache/poi/util/DefaultTempFileCreationStrategy.java b/poi/src/main/java/org/apache/poi/util/DefaultTempFileCreationStrategy.java
index 0252b4b684..f2e51d48ab 100644
--- a/poi/src/main/java/org/apache/poi/util/DefaultTempFileCreationStrategy.java
+++ b/poi/src/main/java/org/apache/poi/util/DefaultTempFileCreationStrategy.java
@@ -21,7 +21,6 @@ import static org.apache.poi.util.TempFile.JAVA_IO_TMPDIR;
 
 import java.io.File;
 import java.io.IOException;
-import java.security.SecureRandom;
 
 /**
  * Default implementation of the {@link TempFileCreationStrategy} used by {@link TempFile}:
@@ -41,9 +40,6 @@ public class DefaultTempFileCreationStrategy implements TempFileCreationStrategy
     /** To keep files after JVM exit, set the <code>-Dpoi.keep.tmp.files</code> JVM property */
     public static final String KEEP_FILES = "poi.keep.tmp.files";
 
-    /** random number generator to generate unique filenames */
-    private static final SecureRandom random = new SecureRandom();
-
     /** The directory where the temporary files will be created (<code>null</code> to use the default directory). */
     private File dir;
 
@@ -126,7 +122,7 @@ public class DefaultTempFileCreationStrategy implements TempFileCreationStrategy
 
         // Generate a unique new filename
         // FIXME: Java 7+: use java.nio.Files#createTempDirectory
-        final long n = random.nextLong();
+        final long n = RandomSingleton.getInstance().nextLong();
         File newDirectory = new File(dir, prefix + Long.toString(n));
         createTempDirectory(newDirectory);
 
diff --git a/poi/src/test/java/org/apache/poi/hpsf/basic/TestMetaDataIPI.java b/poi/src/test/java/org/apache/poi/hpsf/basic/TestMetaDataIPI.java
index 0767691879..0bf0b99ce7 100644
--- a/poi/src/test/java/org/apache/poi/hpsf/basic/TestMetaDataIPI.java
+++ b/poi/src/test/java/org/apache/poi/hpsf/basic/TestMetaDataIPI.java
@@ -26,7 +26,6 @@ import static org.junit.jupiter.api.Assertions.assertTrue;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Date;
-import java.util.Random;
 
 import org.apache.commons.io.output.UnsynchronizedByteArrayOutputStream;
 import org.apache.poi.hpsf.CustomProperties;
@@ -36,6 +35,7 @@ import org.apache.poi.hpsf.PropertySetFactory;
 import org.apache.poi.hpsf.SummaryInformation;
 import org.apache.poi.poifs.filesystem.DirectoryEntry;
 import org.apache.poi.poifs.filesystem.POIFSFileSystem;
+import org.apache.poi.util.RandomSingleton;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -583,16 +583,19 @@ final class TestMetaDataIPI {
         StringBuilder sb = new StringBuilder();
         String[] umlaute = { "\u00e4", "\u00fc", "\u00f6", "\u00dc", "$", "\u00d6", "\u00dc",
                 "\u00c9", "\u00d6", "@", "\u00e7", "&" };
-        Random rand = new Random(0); // TODO - no Random - tests should be completely deterministic
         for (int i = 0; i < 5; i++) {
             sb.append(s);
             sb.append(' ');
-            char j = (char) rand.nextInt(220);
+
+            // TODO - no Random - tests should be completely deterministic
+            char j = (char) RandomSingleton.getInstance().nextInt(220);
             j += 33;
             sb.append('>');
             sb.append(Character.valueOf(j));
             sb.append('=');
-            sb.append(umlaute[rand.nextInt(umlaute.length)]);
+
+            // TODO - no Random - tests should be completely deterministic
+            sb.append(umlaute[RandomSingleton.getInstance().nextInt(umlaute.length)]);
             sb.append('<');
         }
         return sb;
diff --git a/poi/src/test/java/org/apache/poi/hssf/usermodel/TestCellStyle.java b/poi/src/test/java/org/apache/poi/hssf/usermodel/TestCellStyle.java
index 06b6eed277..7bfea1b3cf 100644
--- a/poi/src/test/java/org/apache/poi/hssf/usermodel/TestCellStyle.java
+++ b/poi/src/test/java/org/apache/poi/hssf/usermodel/TestCellStyle.java
@@ -32,7 +32,6 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.Calendar;
 import java.util.Date;
-import java.util.Random;
 import java.util.stream.Stream;
 
 import org.apache.poi.hssf.HSSFTestDataSamples;
@@ -48,6 +47,7 @@ import org.apache.poi.ss.usermodel.Row;
 import org.apache.poi.ss.usermodel.Sheet;
 import org.apache.poi.ss.usermodel.Workbook;
 import org.apache.poi.util.LocaleUtil;
+import org.apache.poi.util.RandomSingleton;
 import org.apache.poi.util.TempFile;
 import org.junit.jupiter.api.Test;
 
@@ -414,9 +414,8 @@ final class TestCellStyle {
     @Test
     void test56563() {
         Stream.of("56563a.xls", "56563b.xls").parallel().forEach(fileName -> assertDoesNotThrow(() -> {
-            Random rand = new Random();
             for(int i=0; i<10; i++) {
-                Thread.sleep(rand.nextInt(300));
+                Thread.sleep(RandomSingleton.getInstance().nextInt(300));
                 try (Workbook wb = openSample(fileName)) {
                     for (Row row : wb.getSheetAt(0)) {
                         for (Cell cell : row) {
diff --git a/poi/src/test/java/org/apache/poi/poifs/filesystem/TestFileMagic.java b/poi/src/test/java/org/apache/poi/poifs/filesystem/TestFileMagic.java
index 456ca076ac..b0da3907e7 100644
--- a/poi/src/test/java/org/apache/poi/poifs/filesystem/TestFileMagic.java
+++ b/poi/src/test/java/org/apache/poi/poifs/filesystem/TestFileMagic.java
@@ -33,9 +33,9 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
-import java.util.Random;
 
 import org.apache.poi.POIDataSamples;
+import org.apache.poi.util.RandomSingleton;
 import org.apache.poi.util.TempFile;
 import org.junit.jupiter.api.Test;
 
@@ -165,12 +165,10 @@ class TestFileMagic {
 
     @Test
     void testRandomPatterns() {
-        Random random = new Random();
-
         // just try to trash the functionality with some byte-patterns
         for(int i = 0; i < 1000;i++) {
             final byte[] data = new byte[12];
-            random.nextBytes(data);
+            RandomSingleton.getInstance().nextBytes(data);
 
             // we cannot check for UNKNOWN as we might hit valid byte-patterns here as well
             try {
diff --git a/poi/src/test/java/org/apache/poi/ss/formula/function/ExcelFileFormatDocFunctionExtractor.java b/poi/src/test/java/org/apache/poi/ss/formula/function/ExcelFileFormatDocFunctionExtractor.java
index c73c8667cd..0155ab0fe1 100644
--- a/poi/src/test/java/org/apache/poi/ss/formula/function/ExcelFileFormatDocFunctionExtractor.java
+++ b/poi/src/test/java/org/apache/poi/ss/formula/function/ExcelFileFormatDocFunctionExtractor.java
@@ -37,6 +37,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.Stack;
 import java.util.zip.ZipFile;
@@ -304,7 +305,7 @@ public final class ExcelFileFormatDocFunctionExtractor {
         @Override
         public void endElement(String namespaceURI, String localName, String name) {
             String expectedName = _elemNameStack.peek();
-            if(expectedName != name) {
+            if(!Objects.equals(name, expectedName)) {
                 throw new RuntimeException("close tag mismatch");
             }
             if(matchesPath(0, HEADING_PATH_NAMES)) {
diff --git a/poi/src/test/java/org/apache/poi/util/TestIOUtils.java b/poi/src/test/java/org/apache/poi/util/TestIOUtils.java
index 5e43acaa11..5a0c5c5bdb 100644
--- a/poi/src/test/java/org/apache/poi/util/TestIOUtils.java
+++ b/poi/src/test/java/org/apache/poi/util/TestIOUtils.java
@@ -36,7 +36,6 @@ import java.io.PushbackInputStream;
 import java.nio.ByteBuffer;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.charset.StandardCharsets;
-import java.util.Random;
 
 import org.apache.commons.io.output.UnsynchronizedByteArrayOutputStream;
 import org.apache.poi.EmptyFileException;
@@ -48,7 +47,7 @@ import org.junit.jupiter.api.parallel.Isolated;
 @Isolated   // this test changes global static BYTE_ARRAY_MAX_OVERRIDE
 final class TestIOUtils {
     private static File TMP;
-    private static final long LENGTH = 300 + new Random().nextInt(9000);
+    private static final long LENGTH = 300 + RandomSingleton.getInstance().nextInt(9000);
 
     @BeforeAll
     public static void setUp() throws IOException {