优化

app/src/main/java/io/legado/app/lib/icu4j/CharsetMatch.java

@@ -1,6 +1,6 @@
 // © 2016 and later: Unicode, Inc. and others.
 // License & terms of use: http://www.unicode.org/copyright.html
-/**
+/*
  * ******************************************************************************
  * Copyright (C) 2005-2016, International Business Machines Corporation and    *
  * others. All Rights Reserved.                                                *
@@ -85,13 +85,13 @@ public class CharsetMatch implements Comparable<CharsetMatch> {
      * @stable ICU 3.4
      */
     public String getString(int maxLength) throws java.io.IOException {
-        String result = null;
+        String result;
         if (fInputStream != null) {
             StringBuilder sb = new StringBuilder();
             char[] buffer = new char[1024];
             Reader reader = getReader();
             int max = maxLength < 0 ? Integer.MAX_VALUE : maxLength;
-            int bytesRead = 0;
+            int bytesRead;
 
             while ((bytesRead = reader.read(buffer, 0, Math.min(max, 1024))) >= 0) {
                 sb.append(buffer, 0, bytesRead);
@@ -231,7 +231,7 @@ public class CharsetMatch implements Comparable<CharsetMatch> {
     //  If user gave us a byte array, this is it.
     private int fRawLength;           // Length of data in fRawInput array.
 
-    private InputStream fInputStream = null;  // User's input stream, or null if the user
+    private final InputStream fInputStream;  // User's input stream, or null if the user
     //   gave us a byte array.
 
     private final String fCharsetName;         // The name of the charset this CharsetMatch

app/src/main/java/io/legado/app/lib/icu4j/CharsetRecog_2022.java

@@ -45,7 +45,7 @@ abstract class CharsetRecog_2022 extends CharsetRecognizer {
                     byte[] seq = escapeSequences[escN];
 
                     if ((textLen - i) < seq.length) {
-                        continue checkEscapes;
+                        continue;
                     }
 
                     for (j = 1; j < seq.length; j++) {

app/src/main/java/io/legado/app/lib/icu4j/CharsetRecog_mbcs.java

@@ -159,8 +159,7 @@ abstract class CharsetRecog_mbcs extends CharsetRecognizer {
                 done = true;
                 return -1;
             }
-            int byteValue = det.fRawInput[nextIndex++] & 0x00ff;
+            return det.fRawInput[nextIndex++] & 0x00ff;
-            return byteValue;
         }
     }
 
@@ -322,9 +321,9 @@ abstract class CharsetRecog_mbcs extends CharsetRecognizer {
         @Override
         boolean nextChar(iteratedChar it, CharsetDetector det) {
             it.error = false;
-            int firstByte = 0;
+            int firstByte;
-            int secondByte = 0;
+            int secondByte;
-            int thirdByte = 0;
+            int thirdByte;
             //int fourthByte = 0;
 
             buildChar:
@@ -374,7 +373,7 @@ abstract class CharsetRecog_mbcs extends CharsetRecognizer {
                 }
             }
 
-            return (it.done == false);
+            return (!it.done);
         }
 
         /**
@@ -466,10 +465,10 @@ abstract class CharsetRecog_mbcs extends CharsetRecognizer {
         @Override
         boolean nextChar(iteratedChar it, CharsetDetector det) {
             it.error = false;
-            int firstByte = 0;
+            int firstByte;
-            int secondByte = 0;
+            int secondByte;
-            int thirdByte = 0;
+            int thirdByte;
-            int fourthByte = 0;
+            int fourthByte;
 
             buildChar:
             {
@@ -510,11 +509,10 @@ abstract class CharsetRecog_mbcs extends CharsetRecognizer {
                     }
 
                     it.error = true;
-                    break buildChar;
                 }
             }
 
-            return (it.done == false);
+            return (!it.done);
         }
 
         static int[] commonChars =

app/src/main/java/io/legado/app/lib/icu4j/CharsetRecog_sbcs.java

@@ -263,6 +263,7 @@ abstract class CharsetRecog_sbcs extends CharsetRecognizer {
         return parser.parse(det, spaceChar);
     }
 
+    @SuppressWarnings("SameParameterValue")
     int matchIBM420(CharsetDetector det, int[] ngrams, byte[] byteMap, byte spaceChar) {
         NGramParser_IBM420 parser = new NGramParser_IBM420(ngrams, byteMap);
         return parser.parse(det, spaceChar);