Changed order of checking supported charset and opening file.

This avoids file handle leak in testcase when unsupported charsets would leave file open

(Could also happen in real code, but probably not in real-life issues)

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/io/trunk@1718429 13f79535-47bb-0310-9956-ffa450edef68

Author: krosenvold

src/main/java/org/apache/commons/io/input/ReversedLinesFileReader.java

@@ -96,19 +96,6 @@ public ReversedLinesFileReader(final File file, final int blockSize, final Chars
         this.blockSize = blockSize;
         this.encoding = encoding;
 
-        randomAccessFile = new RandomAccessFile(file, "r");
-        totalByteLength = randomAccessFile.length();
-        int lastBlockLength = (int) (totalByteLength % blockSize);
-        if (lastBlockLength > 0) {
-            totalBlockCount = totalByteLength / blockSize + 1;
-        } else {
-            totalBlockCount = totalByteLength / blockSize;
-            if (totalByteLength > 0) {
-                lastBlockLength = blockSize;
-            }
-        }
-        currentFilePart = new FilePart(totalBlockCount, lastBlockLength, null);
-
         // --- check & prepare encoding ---
         final Charset charset = Charsets.toCharset(encoding);
         final CharsetEncoder charsetEncoder = charset.newEncoder();
@@ -121,7 +108,7 @@ public ReversedLinesFileReader(final File file, final int blockSize, final Chars
             // http://en.wikipedia.org/wiki/UTF-8
             byteDecrement = 1;
         } else if(charset == Charset.forName("Shift_JIS") || // Same as for UTF-8
-                                      // http://www.herongyang.com/Unicode/JIS-Shift-JIS-Encoding.html
+                // http://www.herongyang.com/Unicode/JIS-Shift-JIS-Encoding.html
                 charset == Charset.forName("windows-31j") || // Windows code page 932 (Japanese)
                 charset == Charset.forName("x-windows-949") || // Windows code page 949 (Korean)
                 charset == Charset.forName("gbk") || // Windows code page 936 (Simplified Chinese)
@@ -138,10 +125,26 @@ public ReversedLinesFileReader(final File file, final int blockSize, final Chars
             throw new UnsupportedEncodingException("Encoding " + encoding + " is not supported yet (feel free to " +
                     "submit a patch)");
         }
+
         // NOTE: The new line sequences are matched in the order given, so it is important that \r\n is BEFORE \n
         newLineSequences = new byte[][] { "\r\n".getBytes(encoding), "\n".getBytes(encoding), "\r".getBytes(encoding) };
 
         avoidNewlineSplitBufferSize = newLineSequences[0].length;
+
+        // Open file
+        randomAccessFile = new RandomAccessFile(file, "r");
+        totalByteLength = randomAccessFile.length();
+        int lastBlockLength = (int) (totalByteLength % blockSize);
+        if (lastBlockLength > 0) {
+            totalBlockCount = totalByteLength / blockSize + 1;
+        } else {
+            totalBlockCount = totalByteLength / blockSize;
+            if (totalByteLength > 0) {
+                lastBlockLength = blockSize;
+            }
+        }
+        currentFilePart = new FilePart(totalBlockCount, lastBlockLength, null);
+
     }
 
     /**