java词法分析器【自己改编的】
SrcAnalyse.java
import 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();
}
}