lex_编译原理_java_词法分析器_lex读取文件_lex描述文件_

package LEX; import javax.swing.*; import javax.swing.table.DefaultTableModel; import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.FlowLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.io.BufferedReader; import java.io.File; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; public class lex { static String[] key = { "do", "end", "for", "if", "printf", "scanf", "then", "while", "int", "float", "false", "true", "then", "char", "break", "long", "return", "static", "struct", "void" }; //关键字表 static String code = "", file = ""; static char[] codex; static int row = 1, n = 0, temp = 0, now; //temp：数据类型 n:第 n 个 static JFrame frame, tab; static JTable jt; static JButton chooseButton, startButton, resetButton; static JTextField fileField; static JPanel northPanel, centralPanel, southPanel; static JTextArea mapArea; //不需要实例化对象就可以引用成员 public static void main(String[] args) throws Exception { creatGUI(); } public static void analysis() { String header[] = { "单词", "二元序列", "类型", "位置" }; DefaultTableModel md = new DefaultTableModel(header, 0); //表格 jt.setModel(md); do { String get = Scanner(); switch (temp) { case -1: String[] forGui = { get, "Error", "Error", "(" + row + "," + n + ")" }; md.addRow(forGui); break; case 0: break; case 1: String[] forGui1 = { get, "(1," + get + ")", "关键字", "(" + row + "," + n + ")" }; md.addRow(forGui1); break; case 2: String[] forGui2 = { get, "(2," + get + ")", "分界符", "(" + row + "," + n + ")" }; md.addRow(forGui2); break; case 3: String[] forGui3 = { get, "(3," + get + ")", "算数运算符", "(" + row + "," + n + ")" }; md.addRow(forGui3); break; case 4: String[] forGui4 = { get, "(4," + get + ")", "关系运算符", "(" + row + "," + n + ")" }; md.addRow(forGui4); break; case 5: String[] forGui5 = { get, "(5," + get + ")", "常数", "(" + row + "," + n + ")" }; md.addRow(forGui5); break; case 6: String[] forGui6 = { get, "(6," + get + ")", "标识符", "(" + row + "," + n + ")" }; md.addRow(forGui6); break; case 7: break; } } while (temp != 0); jt.setModel(md); jt.setAutoResizeMode(JTable.AUTO_RESIZE_ALL_COLUMNS); //表格大小按比例 JScrollPane scroll = new JScrollPane(jt); scroll.setSize(300, 200); tab = new JFrame(); tab.add(scroll); tab.setSize(500, 400); tab.setVisible(true); tab.setTitle("Lex-Analysis"); tab.setLocationRelativeTo(null); //指定位置默认 } public static String Scanner() { //scanner一次执行一个 if (now >= codex.length) { temp = 0; return ""; } //操作结束 char ch = codex[now++]; String token = ""; while (ch == ' ' || ch == '\t' || ch == '\n') { ch = codex[now]; now ++; } if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) { while ((ch >= '0' && ch <= '9') || (ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) { token = token + ch; ch = codex[now++]; } now--; //token提取了整个字符串 token = token.toLowerCase(); //全部转为小写进行比较 for (int i = 0; i < key.length; i++) { //关键字key if (token.equals(key[i])) { temp = 1; n++; return token; } } temp = 6; n++; return token; } else if (ch >= '0' && ch <= '9') { int flag = 0; while (ch !=' ' && ch !=';'&& ch !='/'&& ch!='+'&& ch!='-'&& ch!='*'&& ch!='='&& ch!='<'&& ch!='>' && ch!=','&& ch!='('&& ch!=')'&& ch!='['&& ch!=']'&& ch!='#') { //数字肯定以数字结尾 token = token + ch; if(ch == '.') flag++; if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) { temp = -1; } //数字后面跟字母 ch = codex[now++]; } //小数点不能超过1个 now--; if(flag >= 2) temp = -1; if(temp != -1) temp = 5; n++; return token; } else { switch (ch) { case '<': ch = codex[now++]; if (ch == '>') { temp = 4; n++; return "<>"; } else if (ch == '=') { temp = 4; n++; return "<="; } else { now--; temp = 4; n++; return "<"; } case '>': ch = codex[now++]; if (ch == '=') { temp = 4; n++; return ">="; } else { now--; temp = 4; n++; return ">"; } case '=': ch = codex[now++]; if (ch == '=') { temp = 4; n++; return "=="; } else { now--; n++; temp = 4; return "="; } case '#': row ++; n = 0; temp = 7; return ""; //手动在每一行行末尾加上了#以便判断 case '+': ch = codex[now++]; if (ch == '+') { temp = -1; n++; return "++"; } else { temp = 3; n++; now--; return "+"; } case '-': ch = codex[now++]; if (ch == '-') { temp = -1; n++; return "--"; } else { temp = 3; n++; now--; return "-"; } case '*': if(codex[now++]!='/'){ temp = 3; n++; now--; return "*"; }else{ temp = 2; n++; return "*/"; } case '/': ch = codex[now++]; if(ch!='/'&&ch!='*'){ temp = 3; n++; now--; return "/"; }else if(ch=='/'){ temp = 2; while (ch != '#') { ch = codex[now]; now ++; } now--; return "//"; //消除换行符 }else if(ch=='*'){ temp = 2; n++; while(ch!='/') { while (ch != '*') { ch = codex[now++]; } ch = codex[now++]; } now = now - 2; return "/*"; //消除换行符 } case '"': temp = 2; n++; return "\""; case '(': temp = 2; n++; return "("; case ')': temp = 2; n++; return ")"; case '[': temp = 2; n++; return "["; case ']': temp = 2; n++; return "]"; case '{': temp = 2; n++; return "{"; case '}': temp = 2; n++; return "}"; case ',': temp = 2; n++; return ","; case ';': temp = 2; n++; return ";"; default: break; } } temp = -1; //其他情况 n++; return String.valueOf(ch); } public static void creatGUI() { chooseButton = new JButton("File"); chooseButton.setBackground(Color.white); chooseButton.setPreferredSize(new Dimension(80, 30)); startButton = new JButton("Start"); startButton.setBackground(Color.white); startButton.setPreferredSize(new Dimension(80, 30)); resetButton = new JButton("Reset"); resetButton.setBackground(Color.white); resetButton.setPreferredSize(new Dimension(80, 30)); fileField = new JTextField("", 23); fileField.setBorder(BorderFactory.createLineBorder(Color.gray)); mapArea = new JTextArea(10, 25); mapArea.setEditable(false); mapArea.setBorder(BorderFactory.createLineBorder(Color.gray)); northPanel = new JPanel(); northPanel.setBackground(Color.white); northPanel.add(fileField); centralPanel = new JPanel(); centralPanel.setBackground(Color.white); centralPanel.add(chooseButton); centralPanel.add(mapArea); southPanel = new JPanel(); southPanel.setBackground(Color.white); southPanel.add(startButton); southPanel.add(resetButton); southPanel.setLayout(new FlowLayout(FlowLayout.RIGHT)); frame = new JFrame(); frame.add(northPanel, BorderLayout.NORTH); frame.add(centralPanel, BorderLayout.CENTER); frame.add(southPanel, BorderLayout.SOUTH); frame.setTitle("Lex"); frame.setLocationRelativeTo(null); frame.setDefaultCloseOperation(JFrame.E