java词法分析器【自己改编的】
SrcAnalyse.javaimport java.awt.*;import java.awt.event.*;import java.io.*;import javax.swing.JButton;public class SrcAnalyse extends Frame implements ActionListener{ int row = 1; int line = 1; public static JButton button1=new JButton("打开文件"); public static JButton button2=new JButton("开始分析"); public static JButton button3=new JButton("退出"); TextArea text = new TextArea(15,60); TextArea analyse_text = new TextArea(15,60); int begin = 0; int end = 0; FileDialog file_dialog_load = new FileDialog(this, "打开文件", FileDialog.LOAD); SrcAnalyse(){ this.setLayout(new FlowLayout()); this.add(text); this.add(button1);//打开 this.add(button2);//分析 this.add(button3);//退出 this.add(analyse_text); analyse_text.setText("分析信息如下: \n"); button1.addActionListener(this); button2.addActionListener(this); button3.addActionListener(this); this.setSize(500, 650); this.setResizable(false);//设为窗口不可变 this.setLocation(400,150); text.setEditable(true); analyse_text.setEditable(false); this.addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent e){ System.exit(0); } }); this.setVisible(true); } public static void main(String[] args) { SrcAnalyse compiler = new SrcAnalyse(); compiler.setTitle("词法分析程序v1.0——（C语言版） Power by luosng007"); } public void actionPerformed(ActionEvent e){ if(e.getSource() == button3){ System.exit(0); }else if(e.getSource() == button1){ file_dialog_load.setVisible(true); File myfile = new File(file_dialog_load.getDirectory(), file_dialog_load.getFile()); try{ BufferedReader bufReader = new BufferedReader(new FileReader(myfile)); String content = ""; String str; while((str = bufReader.readLine()) != null){ content += str + "\n"; text.setText(content); } }catch(IOException ie){ System.out.println("IOexception occurs..."); } }else if(e.getSource() == button2){ analyse_text.setText(""); row = 0; line = 1; analyse(); } }/**词法分析*/ public void analyse(){ String analyse_info = analyse_text.getText(); String content = text.getText(); String content1 =""; if(content.equals("")){ analyse_info += "Text is empty! You havn't input any code!\n"; analyse_text.setText(analyse_info); } else{ int i = 0; int N = content.length(); int state = 0; System.out.println(end); for(i = 0; i < N; i++){ row++; char code; char c = content.charAt(i);//当前读取字符 code = c; System.out.print(code); switch(state){ case 0: if(c == ',' || c == ' ' || c == '\t' || c == '{' || c =='}' || c == '(' || c == ')' || c == ';' || c == '[' || c == ']') { if(isDigit(content.charAt(i - 1)) && isDigit(content.charAt(begin))){ end = i; analyse_text.append("info:0 数值表达式： " + content.substring(begin, end) +'\n'); } state = 0; } else if(c == '+') state = 1; else if(c == '-') state = 2; else if(c == '*') state = 3; else if(c == '/') state = 4; else if(c == '!') state = 5; else if(c == '>') state = 6; else if(c == '<') state = 7; else if(c == '=') state = 8; else if(((int)c) == 10) state = 9;//输入为回车 else if(isLetter(c)) { state = 10; begin = i; } //isDigit(int) else if(isDigit(c)) { begin = i; state = 11; } else if(c == '#') state = 12; else if(c == '&') state = 14; else if(c == '|') state = 15; else if(c == '"') state = 16; else analyse_text.append("line: " + line + " row: " + row + " error: '" + c + "' Undefined character! \n"); break; case 1://标识符为 + //row++; if(c == '+'){ state = 0; analyse_text.append("info:1 运算符'++':\n"); } else if(c == '='){ state = 0; analyse_text.append("info:1 运算符'+=':\n"); }else{ state = 0; analyse_text.append("info:1 运算符 '+':\n"); i--; row--; } break; case 2://标志符为 - if(c == '-') analyse_text.append("info:2 运算符'--':\n"); else if(c == '=') analyse_text.append("info:2 运算符'-=':\n"); else{ analyse_text.append("info:2 运算符'-':\n"); i--; row--; } state = 0; break; case 3://运算符 * if(c == '=') analyse_text.append("info:3 运算符'*=':\n"); else{ analyse_text.append("info:3 运算符'*':\n"); i--; row--; } state = 0; break; case 4://运算符 / if(c == '/'){ if((c=content.charAt(i+1))=='*') state=3; else{ while((c) != '\n'){ c=content.charAt(i); i++; } System.out.println(""); c = content.charAt(i); state = 0; analyse_text.append("info:4 注释部分//: \n"); } }else if(c == '='){ state = 0; analyse_text.append("info:4 运算符/= :\n"); }else{ state = 0; analyse_text.append("info:4 运算符/ :\n"); i--; row--; } break; case 5://运算符 ! if(c == '='){ analyse_text.append("info:5 运算符!= :\n"); state = 0; }else{ state = 0; i--; row--; analyse_text.append("info:5 运算符 !: \n"); } break; case 6://运算符 > if(c == '='){ analyse_text.append("info:6 运算符>= :\n"); state = 0; }else{ state = 0; analyse_text.append("info:6 运算符 >: \n"); } break; case 7://运算符 < if(c == '='){ analyse_text.append("info:7 运算符 <= :\n"); state = 0; }else{ state = 0; analyse_text.append("info:7 运算符<: \n"); } break; case 8://运算符 = if(c == '='){ analyse_text.append("info:8 运算符 == :\n"); state = 0; }else{ state = 0; analyse_text.append("info:8 运算符 = :\n"); } break; case 9://回车 state = 0; row = 1; line ++; analyse_text.append("info:9 回车 : \n"); break; case 10:// 字母 if(isLetter(c) || isDigit(c)){ state = 10; }else{ end = i; String id = content.substring(begin, end); if(isKey(id)) analyse_text.append("info：关键字 : "+id+'\n'); //error_text.appendText("info? : 10" + id + '\n'); else analyse_text.append("info：标识符:" + id + '\n'); i--; row--; state = 0; } break; case 11:// 数字 if(c == 'e' || c == 'E') state = 13; else if(isDigit(c) || c == '.'){ }else { if(isLetter(c)){ analyse_text.append("error: line " + line + " row " + row + " ????\n"); } //i--; //row--; int temp = i; i = find(i,content); row += (i - temp); state = 0; } break; case 12://标识符为# String id = ""; while(c != '<'){ id += c; i++; c = content.charAt(i); System.out.print(c); } if(id.trim().equals("include")){ while(c != '>' && ( c != '\n')){ i++; c = content.charAt(i); System.out.print(c); } if(c == '>') analyse_text.append("info # :12 :\n"); }else analyse_text.append("error: " + "line " + line + ", row " + row + " ?\n"); state = 0; break; case 13:// 检测指数表示方式 if(c == '+' || c == '-' || isDigit(c)){ i++; c = content.charAt(i); while(isDigit(c)){ i++; c = content.charAt(i); } if(isLetter(c) || c == '.'){ analyse_text.append("error line " + line + " row " + row + "指数格式错误！\n"); state = 0; int temp = i; i = find(i,content); row += (i - temp); }else{ end = i; analyse_text.append("info:13 指数: " + content.substring(begin, end) + '\n'); } state = 0; } break; case 14://&& if(c == '&') analyse_text.append("info:14 '&' : \n"); else{ i--; analyse_text.append("info:14 '&&' : \n"); } state = 0; break; case 15://|| if(c == '|') analyse_text.append("info:15 '||': \n"); else{ i--; analyse_text.append("info:15 '|':\n"); } state = 0; break; case 16://"" analyse_text.append("info:16 引号 :"+ '"' + '\n'); i--; state = 0; break; } } } analyse_text.append("分析完成\r\n"); }/**判定是否字母*/ boolean isLetter(char c){ if((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_') return true; return false; }/**判定是否数字*/ boolean isDigit(char c){ if(c >= '0' && c <= '9') return true; return false; }/**判定是否关键字*/ boolean isKey(String str){ if( str.equals("char") || str.equals("double") || str.equals("enum") || str.equals("float") ||str.equals("int") || str.equals("long") || str.equals("short") || str.equals("signed") || str.equals("struct")||str.equals("void") || str.equals("unsigned") || str.equals("union") || str.equals("for") || str.equals("do") || str.equals("while") || str.equals("break") || str.equals("continue") || str.equals("if")||str.equals("else")||str.equals("goto") || str.equals("switch") || str.equals("case") || str.equals("default") || str.equals("return") || str.equals("auto")||str.equals("extern")||str.equals("register")||str.equals("static") ||str.equals("const")||str.equals("sizeof")||str.equals("typedef")||str.equals("volatile") ) return true; return false; }/**寻找分隔符空格、括号、回车*/ int find(int begin, String str){ if(begin >= str.length()) return str.length(); for(int i = begin; i < str.length(); i++){ char c = str.charAt(i); if(c == '\n' || c == ',' || c == ' ' || c == '\t' || c == '{' || c =='}' || c == '(' || c == ')' || c == ';' || c == '=' || c == '+'|| c == '-' || c == '*' || c == '/') return i - 1; } return str.length(); }}
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