java 实现词法分析器以及语法分析器

package com.oxford.linkidea; import java.io.File; import java.io.FileReader; import java.util.Stack; public class SyntaxThink2 { private static String path = "/home/liujin/workspace2/Demo/expression_input.txt"; private static String path2="/home/liujin/workspace2/Demo/oxford.txt"; static Stack stack = new Stack(); static String[] data; static int count=-1; static int flag = 0; //LL（1）分析表，数组中E`由A代替，T`由B代替 static String[][] list ={{"","i","+","*","(",")","#"}, {"E","TA",null,null,"TA",null,null}, {"A",null,"+TA",null,null,"@","@"}, {"T","FB",null,null,"FB",null,null}, {"B",null,"@","*FB",null,"@","@"}, {"F","i",null,null,"(E)",null,null} }; /* * 读取文件 */ public static String getFileContent(String paths) throws Exception{ File file= new File(paths); String expression_input = null; if(!file.exists()){ System.out.println("文件不存在，请输入正确的文件路径"); } FileReader fr = new FileReader(file); int rs = 0; char []buf = new char[1024]; while((rs = fr.read(buf)) > 0){ expression_input = new String(buf,0,rs).trim(); } fr.close(); return expression_input; } /** * 判断是否是终结符 * @param args * @throws Exception */ public static boolean isVn(String str){ if(str.equals("E")||str.equals("A")||str.equals("T")||str.equals("B")||str.equals("F")) return true; return false; } @SuppressWarnings("unchecked") public static int Vn_menthod_i(String str,int i){ if(str.equals("E")){ stack.pop(); stack.push("A"); stack.push("T"); }else if(str.equals("A")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("T")){ stack.pop(); stack.push("B"); stack.push("F"); }else if(str.equals("B")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("F")){ stack.pop(); stack.push("i"); } return i ; } @SuppressWarnings("unchecked") public static int Vn_menthod_add(String str,int i){ if(str.equals("E")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("A")){ stack.pop(); stack.push("A"); stack.push("T"); stack.push("+"); }else if(str.equals("T")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("B")){ stack.pop(); }else if(str.equals("F")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } } return i; } @SuppressWarnings("unchecked") public static int Vn_menthod_chen(String str,int i){ if(str.equals("E")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("A")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("T")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("B")){ stack.pop(); stack.push("B"); stack.push("F"); stack.push("*"); }else if(str.equals("F")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } } return i; } @SuppressWarnings("unchecked") public static int Vn_menthod_left(String str,int i){ if(str.equals("E")){ stack.pop(); stack.push("A"); stack.push("T"); }else if(str.equals("A")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("T")){ stack.pop(); stack.push("B"); stack.push("F"); }else if(str.equals("B")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("F")){ stack.pop(); stack.push(")"); stack.push("E"); stack.push("("); } return i ; } public static int Vn_menthod_right(String str,int i){ if(str.equals("E")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("A")){ stack.pop(); }else if(str.equals("T")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("B")){ stack.pop(); }else if(str.equals("F")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } } return i ; } public static int Vn_menthod_last(String str,int i){ if(str.equals("E")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("A")){ stack.pop(); }else if(str.equals("T")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }else if(str.equals("B")){ stack.pop(); }else if(str.equals("F")){ count++; if(count<data.length){ System.out.println(data[count]); System.out.println("输出:错误"); while(!stack.empty()){ stack.pop();// 将数据弹出堆栈 } i = data[count].length()+flag; stack.push("error"); } }