java实现代码高亮

java实现代码高亮

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  1 package JavaSyntaxHighterDemo;
  2  
  3 import java.io.BufferedReader;
  4 import java.io.File;
  5 import java.io.FileInputStream;
  6 import java.io.InputStreamReader;
  7 import java.util.Arrays;
  8 import java.util.HashSet;
  9 import java.util.Set;
 10  
 11 /**
 12  * @author Kevin Tse
 13  * @version 0.1
 14  */
 15 public class JavaSyntaxHighlighter {
 16  
 17     public static int STATE_TEXT = 1; // 普通文本
 18     public static int STATE_DOUBLE_QUOTE = 2; // 双引号
 19     public static int STATE_SINGLE_QUOTE = 3; // 单引号
 20     public static int STATE_MULTI_LINE_COMMENT = 4; // 多行注释
 21     public static int STATE_LINE_COMMENT = 5; // 单行注释
 22  
 23     private int lineNumber; // 行号
 24     private boolean enableLineNumber = true; // 开启行号标志
 25  
 26     public boolean isEnableLineNumber() {
 27         return enableLineNumber;
 28     }
 29  
 30     // line numbers are printed by default.
 31     // but this behavior can be disabled by invoking this method and setting the
 32     // flag to false
 33     public void setEnableLineNumber(boolean enableLineNumber) {
 34         this.enableLineNumber = enableLineNumber;
 35     }
 36  
 37     String[] literalArray = { "null", "true", "false" };    //字面常量
 38     String[] keywordArray = { "abstract", "break", "case", "catch", "class",
 39             "const", "continue", "default", "do", "else", "extends", "final",
 40             "finally", "for", "goto", "if", "implements", "import",
 41             "instanceof", "interface", "native", "new", "package", "private",
 42             "protected", "public", "return", "static", "strictfp", "super",
 43             "switch", "synchronized", "this", "throw", "throws", "transient",
 44             "try", "volatile", "while" };                  //关键词
 45     String[] primitiveTypeArray = { "boolean", "char", "byte", "short", "int",
 46             "long", "float", "double", "void" };           //原始数据类型
 47  
 48     Set literalSet = new HashSet(Arrays.asList(literalArray));
 49     Set keywordSet = new HashSet(Arrays.asList(keywordArray));
 50     Set primitiveTypeSet = new HashSet(Arrays
 51             .asList(primitiveTypeArray));
 52  
 53     public String process(String src) {
 54         int currentState = STATE_TEXT;
 55         int identifierLength = 0;
 56         int currentIndex = -1;
 57         char currentChar = 0;
 58         String identifier = "";
 59         StringBuffer out = new StringBuffer();
 60  
 61         while (++currentIndex != src.length() - 1) {
 62             currentChar = src.charAt(currentIndex);
 63             if (Character.isJavaIdentifierPart(currentChar)) {
 64                 out.append(currentChar);
 65                 ++identifierLength;
 66                 continue;
 67             }
 68             if (identifierLength > 0) {
 69                 identifier = out.substring(out.length() - identifierLength);
 70                 if (currentState == STATE_TEXT) {
 71                     if (literalSet.contains(identifier)) { // identifier is a
 72                                                             // literal
 73                         out.insert(out.length() - identifierLength,
 74                                 "
");
 75                         out.append("
");
 76                     } else if (keywordSet.contains(identifier)) { // identifier
 77                                                                     // is a
 78                                                                     // keyword
 79                         out.insert(out.length() - identifierLength,
 80                                 "
");
 81                         out.append("
");
 82                     } else if (primitiveTypeSet.contains(identifier)) { // identifier
 83                                                                         // is a
 84                                                                         // primitive
 85                                                                         // type
 86                         out.insert(out.length() - identifierLength,
 87                                 "
");
 88                         out.append("
");
 89                     } else if (identifier.equals(identifier.toUpperCase())
 90                             && !Character.isDigit(identifier.charAt(0))) { // identifier
 91                                                                             // is
 92                                                                             // a
 93                                                                             // constant
 94                         out.insert(out.length() - identifierLength,
 95                                 "
");
 96                         out.append("
");
 97                     } else if (Character.isUpperCase(identifier.charAt(0))) { // identifier
 98                                                                                 // is
 99                                                                                 // non-primitive
100                                                                                 // type
101                         out.insert(out.length() - identifierLength,
102                                 "
");
103                         out.append("
");
104                     }
105                 }
106             }
107  
108             switch (currentChar) {
109             // because I handle the "greater than" and "less than" marks
110             // somewhere else, I comment them out here
111             // case '<':
112             // out.append("<");
113             // break;
114             // case '>':
115             // out.append(">");
116             // break;
117             case '\"':
118                 out.append('\"');
119                 if (currentState == STATE_TEXT) {
120                     currentState = STATE_DOUBLE_QUOTE;
121                     out.insert(out.length() - ("\"").length(),
122                             "
");
123                 } else if (currentState == STATE_DOUBLE_QUOTE) {
124                     currentState = STATE_TEXT;
125                     out.append("
");
126                 }
127                 break;
128             case '\'':
129                 out.append("\'");
130                 if (currentState == STATE_TEXT) {
131                     currentState = STATE_SINGLE_QUOTE;
132                     out.insert(out.length() - ("\'").length(),
133                             "
");
134                 } else if (currentState == STATE_SINGLE_QUOTE) {
135                     currentState = STATE_TEXT;
136                     out.append("
");
137                 }
138                 break;
139             case '\\':
140                 out.append("\\");
141                 if (currentState == STATE_DOUBLE_QUOTE
142                         || currentState == STATE_SINGLE_QUOTE) {
143                     // treat as a character escape sequence
144                     out.append(src.charAt(++currentIndex));
145                 }
146                 break;
147             // if you want to translate tabs into spaces, uncomment the
148             // following lines
149             // case '\t':
150             // // replace tabs with tabsize number of spaces
151             // for (int i = 0; i < tabSize; i++)
152             // out.append("    ");
153             // break;
154             case '*':
155                 out.append('*');
156                 if (currentState == STATE_TEXT && currentIndex > 0
157                         && src.charAt(currentIndex - 1) == '/') {
158                     out.insert(out.length() - ("/*").length(),
159                             "
");
160                     currentState = STATE_MULTI_LINE_COMMENT;
161                 }
162                 break;
163             case '/':
164                 out.append("/");
165                 if (currentState == STATE_TEXT && currentIndex > 0
166                         && src.charAt(currentIndex - 1) == '/') {
167                     out.insert(out.length() - ("//").length(),
168                             "
");
169                     currentState = STATE_LINE_COMMENT;
170                 } else if (currentState == STATE_MULTI_LINE_COMMENT) {
171                     out.append("
");
172                     currentState = STATE_TEXT;
173                 }
174                 break;
175             case '\r':
176             case '\n':
177                 // end single line comments
178                 if (currentState == STATE_LINE_COMMENT) {
179                     out.insert(out.length() - 1, "
");
180                     currentState = STATE_TEXT;
181                 }
182                 if (currentChar == '\r' && currentIndex < src.length() - 1) {
183                     out.append("\r\n");
184                     ++currentIndex;
185                 } else
186                     out.append('\n');
187  
188                 if (enableLineNumber)
189                     out.append("
"
190                             + (++lineNumber) + ".
");
191                 break;
192             case 0:
193                 if (currentState == STATE_LINE_COMMENT
194                         && currentIndex == (src.length() - 1))
195                     out.append("

"); 196 break; 197 default: // everything else 198 out.append(currentChar); 199 } 200 identifierLength = 0; 201 } 202 return out.toString(); 203 } 204 205 // test the program by reading a Java file as a String and letting the 206 // program process the source code 207 public static void main(String args[]) throws Exception { 208 File file = new File( 209 "src/JavaSyntaxHighterDemo/JavaSyntaxHighlighter.java"); 210 BufferedReader br = new BufferedReader(new InputStreamReader( 211 new FileInputStream(file), "UTF-8")); 212 StringBuffer sb = new StringBuffer(); 213 String temp = null; 214 while ((temp = br.readLine()) != null) { 215 sb.append(temp).append('\n'); 216 } 217 String src = sb.toString(); 218 JavaSyntaxHighlighter jsh = new JavaSyntaxHighlighter(); 219 System.out.println(jsh.process(src)); 220 } 221 222 }

 

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转载于:https://www.cnblogs.com/lichangyu/p/5103733.html