dbcompile.java

一个用JAVA语言实现的SQL编译器。能够迅速实现对SQL语言的解析。

import java.io.*;
import java.util.Iterator;
import java.util.Vector;
import java.awt.*;
import java.awt.event.*;

import javax.swing.JButton;
import javax.swing.JTextField;
public class DBcompile {

	public static void main(String []args){
		
		Frame f=new Frame("TEST");					//生成窗口				
		f.setSize(500,430);							//窗口大小
		f.setLocation(500, 200);					//窗口位置
		f.addWindowListener(new WindowAdapter(){	//窗口关闭按钮
			public void windowClosing(WindowEvent e){
				System.exit(0);
			}
		});
		//f.setResizable(false);
		JButton btn=new JButton("Perform");			//添加按钮
		btn.setSize(50, 100);						//按钮大小
		
		TextArea t=new TextArea();					//添加输入框
		t.setSize(400, 100);						//输入框大小
		TextArea t1=new TextArea();					//添加输出框
		t1.setSize(400, 200);
		t1.setEditable(false);
		f.setLayout(new FlowLayout(FlowLayout.CENTER));
		
		f.add(t);
		f.add(btn);	
		f.add(t1);
		SC sc=new SC(t,t1);							//StateChange类包含了状态转移的所有操作
		btn.addActionListener(sc);
		
	
		f.setVisible(true);
		
	}

}
class SC implements ActionListener{
	public static TableManager tm = new TableManager();
	
	 char des;
	 int pos=-1;
	 Vector table=new Vector();
	 Vector tablename;
	 Vector column;
	 Vector type;
	 Vector bound;
	 Vector value;
	 Vector refer;
	 Vector conj;
	 Vector standard;
	 Vector value1;
	 Vector function;
	 Vector othername;
	 
	 int []nextStatus=new int[7];				//初始状态集合
	 String action,by;
	 File a=new File("rule1.txt");				//状态规则文件
	 File b=new File("source.txt");				//sql语句源文件
	 File c=new File("des.txt");				//目标操作过程文件
	 File d=new File("key.txt");	
	 InputStreamReader in;
	 BufferedReader in1;
	 BufferedWriter out;
	 String sign;
	 String next;
	 String result;
	 boolean end,order;
	 String op[],ref[],key[],punc[],r[],datatype[],func[],conn[];
	 String rules[][];
	 TextArea t;
	 TextArea t1;
	 String outscreen;
	 
	 public SC(TextArea t,TextArea t1) {
		this.t=t;
		this.t1=t1;// TODO Auto-generated constructor stub
	}

	public void actionPerformed(ActionEvent e)
	 {
		outscreen="";by="";
		pos=-1;
		nextStatus[0]=0;nextStatus[1]=1;nextStatus[2]=2;nextStatus[3]=136;nextStatus[4]=141;nextStatus[5]=-1;nextStatus[6]=-1;
		action="";
		end=false;order=true;
		sign=" ";
		next="";
		result="";
		t1.setText(" ");
		execute();							//execute()方法是SC类的开始方法
	 }
	 
	 void execute(){
			String rule="",sql="",source;
			int s;
			try {
				//////////////////////////////////////////
				//将关键字key,类型type,关系符ref,操作符op,标点符号punc取出
				in1=new BufferedReader(new FileReader(d)); 

				key=in1.readLine().split(" ");key[0]=key[0].substring(key[0].indexOf(":")+1);
				datatype=in1.readLine().split(" ");datatype[0]=datatype[0].substring(datatype[0].indexOf(":")+1);
				ref=in1.readLine().split(" ");ref[0]=ref[0].substring(ref[0].indexOf(":")+1);
				op=in1.readLine().split(" ");op[0]=op[0].substring(op[0].indexOf(":")+1);
				punc=in1.readLine().split(" ");punc[0]=punc[0].substring(punc[0].indexOf(":")+1);
				func=in1.readLine().split(" ");func[0]=func[0].substring(func[0].indexOf(":")+1);
				in1.close();
				
				//////////////////////////////////////////
				//将状态转换表规则取出，r以行为单位
				in=new InputStreamReader(new FileInputStream(a));
				
				while((s=in.read())!=-1){
					rule+=(char)s;
				}
				r=rule.split("\n");
				for(int i=0;i<r.length;i++)
					r[i]=r[i].substring(0,r[i].length()-1);
				//////////////////////////////////////////
				//rules存储表中每个单位
				rules=new String[r.length][5];
				
				for(int i=0;i<rules.length;i++)
				{
					rules[i]=r[i].split(" ");
				}
				//////////////////////////////////////////
				//将sql语句取出
				//System.out.println(t.getSelectedText());
				sql=t.getSelectedText();
				if(sql==""||sql.length()<=1) sql=t.getText();
				sql=sql.substring(0,sql.indexOf(";")+1);
				sql=sql.toLowerCase();
				if(sql==null || sql.equals("")) {
					outscreen+="please enter the sql\n";
					return;
				}
				else sql="$ "+sql;

				//////////////////////////////////////////
				//将sql语句规范化
				String tmp[] = null;
				for(int i=0;i<sql.length();i++)			//加空格
				{
					for(int k=0;k<3;k++)
					{
						switch(k){
						case 0:tmp=op;break;
						case 1:tmp=ref;break;
						case 2:tmp=punc;
						}
						for(int j=0;j<tmp.length;j++)
						{
							if(tmp[j].equals(sql.charAt(i)+""))
								if((sql.charAt(i)=='<'||sql.charAt(i)=='>'||sql.charAt(i)=='!') && sql.charAt(i+1)=='=')
								{
									sql = sql.substring(0, i) + " " + sql.charAt(i)
											+ sql.charAt(i + 1) + " "
											+ sql.substring(i + 2);
									i += 3;
									break;
								}else {
									sql=sql.substring(0, i)+" "+sql.charAt(i)
										+" "+sql.substring(i+1);
									i+=2;
									break;
								}
						}
					}
				}
				sql=sql.replace("\n"," ");
				sql=sql.replace("\t"," ");
				sql=sql.replace("\r"," ");
				
				while(sql.contains("  "))				//去空格
					sql=sql.replace("  "," ");
				//////////////////////////////////////////
				System.out.println(sql);
				process(sql);
				
				//////////////////////////////////////////
				//写文件
				out=new BufferedWriter(new FileWriter(c));
				out.write(sql);
				out.flush();
				out.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
	 }
	 
	 void process(String sql)
	 {
		 int p,q;
		 String nS[];
		 String s="",s1="";
		 String sqls[]=sql.split(" ");
		 for(int i=0 ;i<sqls.length;i++)	//sql语句预处理
		 {
			 s+=recognize(sqls[i])+" ";
		 }
		 s1=s;
		while(s1.contains("varchar ( number )"))
		{
			p=sql.indexOf("varchar");
			q=sql.substring(p).indexOf(")");
			sql=sql.substring(0,p)+"string"+sql.substring(p+q+1);
			s1=s1.substring(s1.indexOf("varchar ( number )")+7);
		}
		s=s.replace("varchar ( number )", "datatype");
		sqls=sql.split(" ");
		System.out.println(sql);
		System.out.println(s);
		 String sql1[]=s.split(" ");
		 int j=0;
		 for(int i=0;i<nextStatus.length;i++)
		 {
			 if(nextStatus[i]==-1) break;
			 if(rules[nextStatus[i]][1].equals(sql1[j]) && rules[nextStatus[i]][2].equals(sql1[j+1]))
			 {
				 System.out.println(r[nextStatus[i]]);
				 s=rules[nextStatus[i]][3];
				 if(!action(s,sqls[j]))
					 break;
				 nS=rules[nextStatus[i]][4].split(",");
				 for(int k=0;k<nS.length;k++)
					 nextStatus[k]=Integer.parseInt(nS[k]);
				 for(int k=nS.length;k<nextStatus.length;k++)
					 nextStatus[k]=-1;
				 j++;
				 i=-1;
				 continue;
			 }
		 }
		 if(nextStatus[0]==-1)
			 {
			 outscreen+="success!\n";
			 switch(des){
				case 't':actionTable();
						 tablename.removeAllElements();
						 column.removeAllElements();
	 					 type.removeAllElements();
	 					 bound.removeAllElements();
						 break;
				case 'i':actionInsert();
						 tablename.removeAllElements();
						 column.removeAllElements();
						 value.removeAllElements();
				 		 break;
				case 'u':actionUpdate();
						 conj.removeAllElements();
						 refer.removeAllElements();
						 column.removeAllElements();
						 tablename.removeAllElements();
						 value.removeAllElements();
						 value1.removeAllElements();
						 standard.removeAllElements();
						 break;
				case 'd':actionDelete();
						 conj.removeAllElements();
						 refer.removeAllElements();
						 tablename.removeAllElements();
						 value.removeAllElements();
						 standard.removeAllElements();
						 break;
				case 's':actionSelect();
						 othername.removeAllElements();
						 function.removeAllElements();
					   	 column.removeAllElements();
						 conj.removeAllElements();
						 refer.removeAllElements();
						 tablename.removeAllElements();
						 value.removeAllElements();
						 standard.removeAllElements();
						 break;			
				}
			 t1.setText(outscreen);
			 }
		 else {
			 outscreen+="wrong!\n";
			 t1.setText(outscreen);
		 }
	 }
	private void actionSelect() {
		String tableName=(String)tablename.get(0);
		TableStructure ts = tm.getTable(tableName);
		if(ts==null){
			outscreen+="Can't find the table!\n";