java实现词法分析代码，java词法代码,编译原理实验课上用Jav

java实现词法分析代码，java词法代码,编译原理实验课上用Jav

编译原理实验课上用Java实现词法分析

编译原理 词法分析（一部分）

package com.java.wei;import java.awt.BorderLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JPanel;import javax.swing.JScrollPane;import javax.swing.JTextArea;import javax.swing.JTextField;import static com.java.wei.DefineUtil.*;public class theFirst extends JFrame{ private JTextField jtf1 = new JTextField(); private JTextArea jta1 = new JTextArea(); private  JPanel jp1 = new JPanel(); private JFrame frame = new JFrame(); private JButton button = new JButton("编译"); public theFirst(){  jp1.setLayout(new BorderLayout());  JPanel p1 = new JPanel();  p1.setLayout(new BorderLayout());  p1.add(new JLabel("输入一段程序"),BorderLayout.WEST);  p1.add(jtf1,BorderLayout.CENTER);  jp1.add(p1,BorderLayout.NORTH);  jp1.add(new JScrollPane(jta1),BorderLayout.CENTER);  jp1.add(button,BorderLayout.SOUTH);  button.addActionListener(new ButtonListener());  frame.add(jp1);  frame.setVisible(true);  frame.setSize(500, 600);  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } public int theSun(int[] array){     int sun =0;     for(int i =0;i<array.length;i++){         sun+=array[i];     }     return sun; } //判断是否是关键字 public boolean isDEFI(String string){     for(int i = 0;i<DEFINESTR.length;i++){         if(string.equals(DEFINESTR[i])){             return true;         }     }     return false; } //判断是否是数字 public boolean isNum(String string){     int[] itRight = new int[string.length()];  for(int i=0;i<string.length();i++){   if(string.charAt(i)>='0'&&string.charAt(i)<='9')       itRight[i]=0;   else itRight[i]=1;  }   if(theSun(itRight)==0){      return true;  }  return false; }// 判断是否是字符串 public boolean isString(String string){    int[] itRight = new int[string.length()];  for(int i=0;i<string.length();i++){   if(string.charAt(i)>='a'&&string.charAt(i)<='z'||string.charAt(i)>='A'&&string.charAt(i)<='Z'){    itRight[i]=0;    }    else {itRight[i]=1;}    }  if(theSun(itRight)==0){      return true;  }  return false; } // 判断师傅是"=“ public boolean isFuzhi(String string){     int[] itRight = new int[string.length()];  for(int i=0;i<string.length();i++){   if(string.charAt(i)=='=')       itRight[i]=0;     else {itRight[i]=1;}  }  if(theSun(itRight)==0){      return true;  }  return false; } //处理各种情况 public String outNum(String string){  String b= null;  if(isNum(string)){   b =string+ITISNUM;  }  else if(isFuzhi(string)){   b =string+ITISFUZ;  }  else if (isString(string)){      if(isDEFI(string)){          b=string+ITISDEF;         }else{          b =string+ITISSTR;      }  }  return b; } //Button监听事件 private class ButtonListener implements ActionListener{  @Override  public void actionPerformed(ActionEvent arg0) {   String in = jtf1.getText().toString();   int i = 0;   int j =0;  // int last = in.length();   String out = null;   for( ;i<in.length();){    //int j= 0;//    System.out.println(in[i]);//    if(in[i]>'a'&&in[i]<'z'||in[i]>'A'&&in[i]<'Z'){//     jta1.append("第"+i+"个是字母");//    }//    if(in[i]>'0'&&in[i]<'9')//     jta1.append("第"+i+"是数字");       //以空格后者是”；“来分割字符串    if(in.charAt(i)==' '||in.charAt(i)==';'){                     out=in.substring(j,i);       j=++i;         String type = outNum(out);       if(type!=null)        jta1.append(type+'\n');       else jta1.append(ITISRON+"\n");    }//    if(in.charAt(i)=='='){//       out=in.substring(j,i);//       j=i;  //       String type = "赋值符号";//          jta1.append(out.toString()+type+'\n');//    }//    if(i==last-1){//     out = in.substring(j);//      String type = outNum(out);//     jta1.append(out+type);//    }    i++;   }  } } public static void main(String[] args){  new theFirst(); }}package com.java.wei;public class DefineUtil {   public final static String[] DEFINESTR = {        "abstract","double","int","super","assert","else","interface",        "switch","boolean","enum","long","synchronized","break",        "extends","native","this","byte","for","new","throw","case",        "final","package","throws","catch","finally","private","transient",        "char","float","protected","try","class","goto","public","void",        "const","if","return","continue","implements","short","while",        "default","import","static","do","instanceof","strictfp"   };   public final static String ITISNUM = "这是个数字";   public final static String ITISSTR ="这是字符串" ;   public final static String ITISDEF = "这是关键字";   public final static String ITISFUZ ="这是赋值符号";   public final static String ITISRON ="书写格式有错误";}