采用java图形化界面编写了java语言的词法分析器，该分析器可识别所有java关键字。软件工程课程中编译原理实验。
Keyword.jvav
package org.kyc.test1;
public class Keyword {
private String keyword; //存储关键字字符
private int keywordindex;//存储关键字的下标
Keyword[] keyW;//存储关键字对象的数组
public Keyword(){
//构造数组
keyW=setKeywordList();
}
public Keyword(String str,int t){
setKeyword(str);
setKeywordindex(t);
}
public String getKeyword() {
return keyword;
}
public void setKeyword(String keyword) {
this.keyword = keyword;
}
public int getKeywordindex() {
return keywordindex;
}
public void setKeywordindex(int keywordindex) {
this.keywordindex = keywordindex;
}
/**
* 创建关键字列表
* @return
*/
public Keyword[] setKeywordList(){
final int PRIVATE=30;// private私有的
final int PROTECTED=31;// protected受保护的
final int PUBLIC=32 ;//public 公共的
//类、方法和变量修饰符
final int ABSTRACT=33;//abstract 声明抽象
final int ClASS=34;// class类
final int EXTEND=35;//extends 扩允,继承
final int FINAL=36;//final 终极,不可改变的
final int IMPLEMENTS=37;//implements实现
final int INTERFACE=38;//interface 接口
final int NATIVE=39;//native 本地
final int NEW=40;//new 新,创建
final int STATIC=41;//static 静态
final int STRICTFP=42;//strictfp 严格,精准
final int SYNCHRONIZED=43;//synchronized 线程,同步
final int TRANSIENT=44;//transient 短暂
final int VOLATILE=45;//volatile 易失
//程序控制语句
final int BREAK=46;//break 跳出循环
final int CONTINUE=47;//continue 继续
final int RETURN=48;//return 返回
final int DO=49;//do 运行
final int WHILE=50;//while 循环
final int IF=51;//if 如果
final int ELSE=52;// else 反之
final int FOR=53;//for 循环
final int INSTANCEOF=54;//instanceof 实例
final int SWITCH=55;//switch 开关
final int CASE=56;//case 返回开关里的结果
final int DEFAULT=57;//default 默认
//错误处理
final int CATCH=58;//catch 处理异常
final int FINALLY=59;//finally 有没有异常都执行
final int THROW=60;//throw 抛出一个异常对象
final int THROWS=61;//throws 声明一个异常可能被抛出
final int TRY=62;//try 捕获异常
//包相关
final int IMPORT=63;//import 引入
final int PACKAGE=64;//package 包
//基本类型
final int BOOLEAN=65;//boolean 布尔型
final int BYTE=66;//byte 字节型
final int CHAR=67;//char 字符型
final int DOUBLE=68;//double 双精度,
final int FLOATE=69;//float 浮点
final int INT=70;//int 整型
final int LONG=71;//long 长整型
final int SHORT=72;//short 短整型
final int NULL=73;//null 空
final int TRUE=74;//true 真
final int FALSE=75;//false 假
//变量引用
final int SUPER=76;//;super 父类,超类
final int THIS=77;//this 本类
final int VOID=78;//void 无返回值
final int CONST=80;//const
final int GOTO=81;//goto
Keyword kwTable[] = {
new Keyword("private", PRIVATE),
new Keyword("protected", PROTECTED),
new Keyword("public", PUBLIC),
//类、方法和变量修饰符
new Keyword("abstract" ,ABSTRACT), // 声明抽象
new Keyword("class", ClASS), // 类
new Keyword("extends" ,EXTEND), // 扩允,继承
new Keyword("final" ,FINAL), // 终极,不可改变的
new Keyword("implements" ,IMPLEMENTS), //实现
new Keyword("interface", INTERFACE), // 接口
new Keyword("native", NATIVE), // 本地
new Keyword("new" ,NEW),// 新,创建
new Keyword("static" ,STATIC), // 静态
new Keyword("strictfp" , STRICTFP), //严格,精准
new Keyword("synchronized",SYNCHRONIZED), // 线程,同步
new Keyword("transient" ,TRANSIENT), // 短暂
new Keyword("volatile" ,VOLATILE), // 易失
//程序控制语句
new Keyword("break" ,BREAK), // 跳出循环
new Keyword("continue" ,CONTINUE), // 继续
new Keyword("return" , RETURN), //返回
new Keyword("do" ,DO), // 运行"
new Keyword("while" ,WHILE), //循环
new Keyword("if",IF), // 如果
new Keyword("else" ,ELSE), // 反之
new Keyword("for" ,FOR), // 循环
new Keyword("instanceof ",INSTANCEOF), // 实例
new Keyword("switch ", SWITCH), //开关
new Keyword("case", CASE), // 返回开关里的结果
new Keyword("default", DEFAULT), // 默认
//错误处理
new Keyword("catch", CATCH), //处理异常
new Keyword("finally", FINALLY), // 有没有异常都执行
new Keyword("throw", THROW), //抛出一个异常对象
new Keyword("throws", THROWS), // 声明一个异常可能被抛出
new Keyword("try", TRY), // 捕获异常
//包相关
new Keyword("import", IMPORT), // 引入
new Keyword("package", PACKAGE), // 包
//基本类型
new Keyword("boolean", BOOLEAN), // 布尔型
new Keyword("byte", BYTE), // 字节型
new Keyword("char", CHAR), // 字符型
new Keyword("double", DOUBLE), // 双精度,
new Keyword("float", FLOATE), // 浮点
new Keyword("int", INT),// 整型
new Keyword("long", LONG), // 长整型
new Keyword("short", SHORT), // 短整型
new Keyword("null", NULL), // 空
new Keyword("true", TRUE), // 真
new Keyword("false", FALSE), // 假
//变量引用
new Keyword("super", SUPER), //, 父类,超类
new Keyword("this", THIS), // 本类
new Keyword("void", VOID), // 无返回值
new Keyword("const" , CONST),
new Keyword("goto", GOTO),
};
return kwTable;
}
/*
* 判断字符串是否为关键字
*/
public boolean isKeyWord(String str){
boolean b=false;
for(int i=0;i<keyW.length;i++){
if(keyW[i].getKeyword().equals(str)||keyW[i].getKeyword()==str){
b=true;
break;
}
}
return b;
}
}
package org.kyc.test1;
public class Operators {
private String strOperators;
private int flagOperators;
private Operators[] oper;
public Operators(){
oper=setOperators();
}
public Operators(String str,int t){
strOperators=str;
flagOperators=t;
}
public String getStrOperators() {
return strOperators;
}
public void setStrOperators(String strOperators) {
this.strOperators = strOperators;
}
public int getFlagOperators() {
return flagOperators;
}
public void setFlagOperators(int flagOperators) {
this.flagOperators = flagOperators;
}
/**
* 创建操作符列表
* @return Operators[]
*/
public Operators[] setOperators(){
Operators operators[]={
new Operators(".",101),
new Operators("(",102),
new Operators(")",103),
new Operators("[",104),
new Operators("]",105),
new Operators("+",106),
new Operators("-",107),
new Operators("++",108),
new Operators("--",109),
new Operators("~",110),
new Operators("!",111),
new Operators("*",112),
new Operators("/",113),
new Operators("//",114),
new Operators("<<",115),
new Operators(">>",116),
new Operators(">>>",117),
new Operators(">",118),
new Operators(">=",119),
new Operators("<=",120),
new Operators("==",121),
new Operators("!=",122),
new Operators("&",123),
new Operators("|",124),
new Operators("?",125),
new Operators(":",126),
new Operators("=",127),
new Operators("+=",128),
new Operators("-=",129),
new Operators("/=",130),
new Operators("%=",131),
new Operators("&=",132),
new Operators("|=",133),
new Operators("^=",134),
new Operators("<<=",135),
new Operators(">>=",136),
new Operators(">>>=",137),
new Operators(";",140),
new Operators("{",141),
new Operators("}",142),
new Operators("\"",143),
new Operators("\'",144),
new Operators("@",145),
new Operators("$",146),
new Operators("\\",147),
new Operators(",",148)
};
return operators;
}
public boolean isOperator(String str){
// 判断字符是否是操作符
boolean b=false;
for(int i=0;i<oper.length;i++){
if(oper[i].getStrOperators().equals(str)||oper[i].getStrOperators()==str){
b=true;
break;
}
}
return b;
}
public boolean isOperator(char c){
// 判断字符是否是操作符
boolean b=false;
for(int i=0;i<oper.length;i++){
if(oper[i].getStrOperators().equals(c)||oper[i].getStrOperators().charAt(0)==c){
b=true;
break;
}
}
return b;
}
public int getNumber(String str){
//返回与字符对应的数字
int f=0;
for(int i=0;i<oper.length;i++){
if(oper[i].getStrOperators().equals(str)||oper[i].getStrOperators()==str){
f=oper[i].getFlagOperators();
break;
}
}
return f;
}
public int getNumber(char c){
int f=0;
for(int i=0;i<oper.length;i++){
if(oper[i].getStrOperators().equals(c)||oper[i].getStrOperators().charAt(0)==c){
f=oper[i].getFlagOperators();
break;
}
}
return f;
}
}
package org.kyc.test1;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
public class CharacterAnalysis {
final int ERROR=0;//错误
final int LETTER=1;//字母
final int NUM=2;//数字
final int NOTE=3;//注释的
private char[] prog;//存储所扫描的程序
private int progIndex;//扫描的下标
private String token;//获取到的字符串
final int PROG_SIZE = 1000000;
// 将关键字的外部表示,和内部表示保存在一个名为KeyWordTable的表中
Keyword keyword=new Keyword();
Keyword keywordTable[] =keyword.setKeywordList();
Operators operator=new Operators();
Operators operatorsTable[]=operator.setOperators();
Object [][] list=new Object[65635][2];
int List_index=0;
public CharacterAnalysis(File file_choosed) throws IOException {
//实现将文件中的字符存到数组中
char tempbuf[] = new char[PROG_SIZE];
int size=0;
try {
FileReader fr = new FileReader(file_choosed);
BufferedReader br = new BufferedReader(fr);
size = br.read(tempbuf, 0, PROG_SIZE);
fr.close();
} catch (FileNotFoundException exc) {
System.out.print("没有找到该文件!");
}
if (size != -1) {
prog = new char[size];
System.arraycopy(tempbuf, 0, prog, 0, size);
}
}
public void Analyse(String str){
this.prog=str.toCharArray();
try {
Analyse();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void Analyse() throws IOException {
// 对代码扫描
do {
token = "";
// 跳过空格符
while(isSpaceOrTab(prog[progIndex])||isnextline(prog[progIndex])){
while (isSpaceOrTab(prog[progIndex])){
progIndex++;
if(progIndex>=prog.length)break;
}
// 处理换行
while (isnextline(prog[progIndex])) {
progIndex ++;
if(progIndex>=prog.length)break;
}
if(progIndex>=prog.length)break;
}
if(progIndex>=prog.length){
break;
}
/*
* 判断是否为注释,并作处理
*/
else if(isMark()){
System.out.println("注释:"+token+" "+NOTE);
AddTolist("注释:"+token,NOTE);
continue;
}
/*
* 是一个操作符,或者是运算符
*/
else if (operator.isOperator(prog[progIndex])) {
//System.out.println("是个操作符");
token += prog[progIndex];
progIndex++;
//继续判断是否为两个符号组成在一起的操作符
if (operator.isOperator(prog[progIndex])){
//判端接下来的操作符是否和前面的操作符能够组成在一起
token += prog[progIndex];
progIndex++;
if (operator.isOperator(token)){
//说明组成在一起了
System.out.println(token+" "+operator.getNumber(token));
AddTolist(token,operator.getNumber(token));
continue;
}
else{
//说明组不到一起
System.out.println(token.charAt(0)+" "+operator.getNumber(token.charAt(0)));
System.out.println(token.charAt(1)+" "+operator.getNumber(token.charAt(1)));
AddTolist(token.charAt(0),operator.getNumber(token.charAt(0)));
AddTolist(token.charAt(1),operator.getNumber(token.charAt(1)));
continue;
}
}
else{
System.out.println(token+" "+operator.getNumber(token));
AddTolist(token,operator.getNumber(token));
continue;
}
}
/*
* 是一个字符变量
*/
else if (Character.isLetter(prog[progIndex])) {
while (Character.isLetterOrDigit(prog[progIndex])||prog[progIndex]=='_') {
//System.out.println("是个字符变量");
token += prog[progIndex];
progIndex++;
if (progIndex >= prog.length)
break;
}
if (keyword.isKeyWord(token)){
//说明是关键字
for(int i=0;i<keywordTable.length;i++){
if(token.equals(keywordTable[i].getKeyword())||token==keywordTable[i].getKeyword()){
System.out.println(token+" "+keywordTable[i].getKeywordindex());
AddTolist(token,keywordTable[i].getKeywordindex());
break;
}
}
}
else{
System.out.println(token + " " + LETTER);
AddTolist(token, LETTER);
}
}
/*
* 是一个数字字符
*/
else if (Character.isDigit(prog[progIndex])) {
while (Character.isDigit(prog[progIndex])) {
token += prog[progIndex];
progIndex++;
if (progIndex >= prog.length)
break;
}
System.out.println(token + " " +NUM );
AddTolist(token, NUM);
}
else {
System.out.println(token+" "+ERROR);
AddTolist(token, ERROR);
progIndex++;
continue;
}
} while (progIndex != prog.length);
System.out.println("程序分析完毕");
}
private boolean isMark() {
// TODO Auto-generated method stub
//判断是否为注释部分
if(prog[progIndex]=='/'&&prog[progIndex+1]=='/'){
while(!isnextline(prog[progIndex])){
token += prog[progIndex];
progIndex++;
}
return true;
}
return false;
}
//判断是否为空格
private boolean isSpaceOrTab(char c) {
if (c == ' ' || c == '\t')
return true;
return false;
}
//判断是否为换行
private boolean isnextline(char c){
if(c== '\r'||c == '\n'){
return true;
}
else{
return false;
}
}
public char[] getProg() {
return prog;
}
public void AddTolist(String str,int num){
list[List_index][0]=str;
list[List_index][1]=num;
List_index++;
}
private void AddTolist(char charAt, int num) {
// TODO Auto-generated method stub
list[List_index][0]=charAt;
list[List_index][1]=num;
List_index++;
}
}
package org.kyc.test1;
package org.kyc.test1;
import java.awt.EventQueue;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextArea;
import javax.swing.border.EmptyBorder;
import java.awt.Font;
/**
* 编译原理实验一——词法分析器
* @author 康雨城
* 2015/6/4
*/
public class View extends JFrame {
private JPanel contentPane;
private JFileChooser fc;
private JTextArea textArea;
private CharacterAnalysis ob;
private JTable table;
private File file_choosed;
String [] cloumnNames= {"词语","分析结果"};
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
View frame = new View();
frame.setVisible(true);
frame.setTitle("词法分析器");
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public View() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 750, 400);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(new GridLayout(1, 2, 0, 0));
fc = new JFileChooser();
fc.setFileSelectionMode(JFileChooser.FILES_AND_DIRECTORIES);
JPanel panel = new JPanel();
contentPane.add(panel);
panel.setLayout(null);
JPanel panel_Left = new JPanel();
panel_Left.setBounds(0, 297, 362, 54);
panel.add(panel_Left);
panel_Left.setLayout(new GridLayout(1, 2, 0, 0));
JScrollPane Left_ScrollPane = new JScrollPane();
Left_ScrollPane.setBounds(0, 0, 362, 297);
panel.add(Left_ScrollPane);
textArea = new JTextArea();
Left_ScrollPane.setViewportView(textArea);
JScrollPane RightScrollPane = new JScrollPane();
contentPane.add(RightScrollPane);
JButton btnSelectFile = new JButton("选取文件");
btnSelectFile.setFont(new Font("宋体", Font.BOLD, 18));
btnSelectFile.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int i=fc.showOpenDialog(null);
if(i==fc.APPROVE_OPTION){
file_choosed = fc.getSelectedFile();
try {
ob = new CharacterAnalysis(file_choosed);
textArea.setText(String.valueOf(ob.getProg()));
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
else {
System.out.println("没有选择文件");
}
}
});
panel_Left.add(btnSelectFile);
JButton btnAnalysis = new JButton("分析");
btnAnalysis.setFont(new Font("宋体", Font.BOLD, 18));
btnAnalysis.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
try {
if(file_choosed==null){
System.out.println("请选择文件！");
}
else{
ob.Analyse();
table=new JTable(ob.list,cloumnNames);
RightScrollPane.setViewportView(table);
table.invalidate();
}
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
});
panel_Left.add(btnAnalysis);
}
}