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  • SqlAnalyzer1.00源码

    SQL解析的夙愿今天终于完成,但限于SQL远超算术表达式,Json,XML等的复杂度,只是解析了一部分。形成普适性的SQL解析,仍需倾注精力。

    代码下载:https://files.cnblogs.com/files/heyang78/SqlAnalyzer-20200527-2.rar

    测试用例:https://www.cnblogs.com/heyang78/p/12974097.html

    核心诸类:

    Token:

    package com.heyang;
    
    public class Token{
        public static final int TYPE_SELECT=1;
        public static final int TYPE_TEXT=2;
        public static final int TYPE_COMMA=3;
        public static final int TYPE_FROM=4;
        public static final int TYPE_WHERE=5;
        public static final int TYPE_AND=6;
        public static final int TYPE_EQUAL=7;
        public static final int TYPE_OR=8;
        public static final int TYPE_ORDER=9;
        public static final int TYPE_BY=10;
        public static final int TYPE_ASC=11;
        public static final int TYPE_DESC=12;
        public static final int TYPE_AS=13;
        public static final int TYPE_GROUP=14;
        public static final int TYPE_HAVING=15;
        public static final int TYPE_LESSTHAN=16;
        public static final int TYPE_GREATERTHAN=17;
        public static final int TYPE_OPEN_PARENTHESIS=18;
        public static final int TYPE_CLOSE_PARENTHESIS=19;
        public static final int TYPE_CONNECT=20;
        public static final int TYPE_LESSTHAN_OR_EQUAL=21;
        public static final int TYPE_GREATERTHAN_OR_EQUAL=22;
        public static final int TYPE_LESSTHAN_OR_GREATERTHAN=23;
        public static final int TYPE_CASE=24;
        public static final int TYPE_WHEN=25;
        public static final int TYPE_THEN=26;
        public static final int TYPE_ELSE=27;
        public static final int TYPE_END=28;
        public static final int TYPE_IS=29;
        public static final int TYPE_NULL=30;
        public static final int TYPE_TRUE=31;
        public static final int TYPE_FALSE=32;
        public static final int TYPE_PLUS=33;
        public static final int TYPE_MINUS=34;
        //public static final int TYPE_MULTI=35;
        public static final int TYPE_DEVIDE=36;
        public static final int TYPE_DISTINCT=37;
        public static final int TYPE_OVER=38;
        public static final int TYPE_STRING_CONCAT=39;
        public static final int TYPE_ON=40;
        public static final int TYPE_JOIN=41;
        public static final int TYPE_INNER=42;
        public static final int TYPE_LEFT=43;
        public static final int TYPE_RIGHT=44;
        public static final int TYPE_OUTER=45;
        public static final int TYPE_FULL=46;
        public static final int TYPE_WITHIN=47;
        public static final int TYPE_PARTITION=48;
        public static final int TYPE_LIKE=49;
        public static final int TYPE_LIMIT=50;
        
        private int type;
        private String text;
        private int index;// Used to remember location
        
        public Token(char c,int type) {
            this.text=String.valueOf(c);
            this.type=type;
        }
        
        public Token(String word,int type) {
            this.text=word;
            this.type=type;
        }
        
        public String toString() {
            return String.format("token(text=%s,type=%s,index=%d)", text,getTypeStr(),index);
        }
        
        public String getTypeStr() {
            if(type==TYPE_SELECT) {
                return "KW:select";
            }else if(type==TYPE_FROM) {
                return "KW:from";
            }else if(type==TYPE_COMMA) {
                return "Comma";
            }else if(type==TYPE_TEXT) {
                return "Text";
            }else if(type==TYPE_WHERE) {
                return "KW:where";
            }else if(type==TYPE_AND) {
                return "KW:and";
            }else if(type==TYPE_EQUAL) {
                return "=";
            }else if(type==TYPE_OR) {
                return "KW:or";
            }else if(type==TYPE_ORDER) {
                return "KW:order";
            }else if(type==TYPE_BY) {
                return "KW:by";
            }else if(type==TYPE_ASC) {
                return "KW:asc";
            }else if(type==TYPE_DESC) {
                return "KW:desc";
            }else if(type==TYPE_AS) {
                return "KW:as";
            }else if(type==TYPE_GROUP) {
                return "KW:group";
            }else if(type==TYPE_HAVING) {
                return "KW:having";
            }else if(type==TYPE_LESSTHAN) {
                return "<";
            }else if(type==TYPE_GREATERTHAN) {
                return ">";
            }else if(type==TYPE_OPEN_PARENTHESIS) {
                return "(";
            }else if(type==TYPE_CLOSE_PARENTHESIS) {
                return ")";
            }else if(type==TYPE_CONNECT) {
                return "KW:connect";
            }else if(type==TYPE_LESSTHAN_OR_EQUAL) {
                return "<=";
            }else if(type==TYPE_GREATERTHAN_OR_EQUAL) {
                return ">=";
            }else if(type==TYPE_LESSTHAN_OR_GREATERTHAN) {
                return "<>";
            }else if(type==TYPE_CASE) {
                return "KW:case";
            }else if(type==TYPE_WHEN) {
                return "KW:when";
            }else if(type==TYPE_THEN) {
                return "KW:then";
            }else if(type==TYPE_ELSE) {
                return "KW:else";
            }else if(type==TYPE_END) {
                return "KW:end";
            }else if(type==TYPE_IS) {
                return "KW:is";
            }else if(type==TYPE_NULL) {
                return "KW:null";
            }else if(type==TYPE_TRUE) {
                return "KW:true";
            }else if(type==TYPE_FALSE) {
                return "KW:false";
            }else if(type==TYPE_PLUS) {
                return "+";
            }else if(type==TYPE_MINUS) {
                return "-";
            }else if(type==TYPE_DEVIDE) {
                return "/";
            }else if(type==TYPE_DISTINCT) {
                return "KW:distinct";
            }else if(type==TYPE_OVER) {
                return "KW:over";
            }else if(type==TYPE_STRING_CONCAT) {
                return "||";
            }else if(type==TYPE_ON) {
                return "KW:on";
            }else if(type==TYPE_JOIN) {
                return "KW:join";
            }else if(type==TYPE_INNER) {
                return "KW:inner";
            }else if(type==TYPE_LEFT) {
                return "KW:left";
            }else if(type==TYPE_RIGHT) {
                return "KW:right";
            }else if(type==TYPE_OUTER) {
                return "KW:outer";
            }else if(type==TYPE_FULL) {
                return "KW:full";
            }else if(type==TYPE_WITHIN) {
                return "KW:within";
            }else if(type==TYPE_PARTITION) {
                return "KW:partition";
            }else if(type==TYPE_LIKE) {
                return "KW:like";
            }else if(type==TYPE_LIMIT) {
                return "KW:limit";
            }
            
            return null;
        }
        
        public int getType() {
            return type;
        }
    
        public String getText() {
            return text;
        }
        
        public void setText(String text) {
            this.text=text;
        }
    
        public int getIndex() {
            return index;
        }
    
        public void setIndex(int index) {
            this.index = index;
        }
    
        public void setType(int type) {
            this.type = type;
        }
    }

    Lexer:

    package com.heyang;
    
    import java.io.BufferedReader;
    import java.io.FileInputStream;
    import java.io.InputStreamReader;
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.List;
    
    
    // v1.00
    public class Lexer {
        private List<Token> tokens;
    
        public Lexer(String inputSql) {
            String sql=pretreat(inputSql);
            String swallowed="";
            
            tokens=new ArrayList<Token>();
            for(int i=0;i<sql.length();i++){
                char c=sql.charAt(i);
                
                if(Character.isWhitespace(c)){
                    addTextToList(swallowed);
                    swallowed="";
                }else if(c==','){
                    addTextToList(swallowed);
                    swallowed="";
                    tokens.add(new Token(c,Token.TYPE_COMMA));
                }else if(c=='='){
                    addTextToList(swallowed);
                    swallowed="";
                    tokens.add(new Token(c,Token.TYPE_EQUAL));
                }else if(c=='<'){
                    int next=i+1;
                    if(next<sql.length() && sql.charAt(next)=='=') {
                        addTextToList(swallowed);
                        swallowed="";
                        tokens.add(new Token("<=",Token.TYPE_LESSTHAN_OR_EQUAL));
                        i++;
                    }else if(next<sql.length() && sql.charAt(next)=='>') {
                        addTextToList(swallowed);
                        swallowed="";
                        tokens.add(new Token("<>",Token.TYPE_LESSTHAN_OR_GREATERTHAN));
                        i++;
                    }else {
                        addTextToList(swallowed);
                        swallowed="";
                        tokens.add(new Token(c,Token.TYPE_LESSTHAN));
                    }
                }else if(c=='>'){
                    int next=i+1;
                    if(next<sql.length() && sql.charAt(next)=='=') {
                        addTextToList(swallowed);
                        swallowed="";
                        tokens.add(new Token(">=",Token.TYPE_GREATERTHAN_OR_EQUAL));
                        i++;
                    }else {
                        addTextToList(swallowed);
                        swallowed="";
                        tokens.add(new Token(c,Token.TYPE_GREATERTHAN));
                    }
                }else if(c=='|'){
                    int next=i+1;
                    if(next<sql.length() && sql.charAt(next)=='|') {
                        addTextToList(swallowed);
                        swallowed="";
                        tokens.add(new Token("||",Token.TYPE_STRING_CONCAT));
                        i++;
                    }
                }else if(c=='('){
                    addTextToList(swallowed);
                    swallowed="";
                    tokens.add(new Token(c,Token.TYPE_OPEN_PARENTHESIS));
                }else if(c==')'){
                    addTextToList(swallowed);
                    swallowed="";
                    tokens.add(new Token(c,Token.TYPE_CLOSE_PARENTHESIS));
                }else if(c=='+'){
                    addTextToList(swallowed);
                    swallowed="";
                    tokens.add(new Token(c,Token.TYPE_PLUS));
                }else if(c=='-'){
                    addTextToList(swallowed);
                    swallowed="";
                    tokens.add(new Token(c,Token.TYPE_MINUS));
                }else if(c=='/'){
                    addTextToList(swallowed);
                    swallowed="";
                    tokens.add(new Token(c,Token.TYPE_DEVIDE));
                }else {
                    swallowed+=c;
                }
            }
            
            setTokenIndexes();
        }
        
        public void setTokenIndexes() {
            int idx = 0;
            for (Token t : tokens) {
                idx++;
                t.setIndex(idx);
            }
        }
        
        private int findTypeByText(String text) {
            Object[][] arr= {
                                {"select", Token.TYPE_SELECT},
                                {"from",   Token.TYPE_FROM},
                                {"where",  Token.TYPE_WHERE},
                                {"and",    Token.TYPE_AND},
                                {"or",     Token.TYPE_OR},
                                {"order",  Token.TYPE_ORDER},
                                {"by",     Token.TYPE_BY},
                                {"asc",    Token.TYPE_ASC},
                                {"desc",   Token.TYPE_ASC},
                                {"asc",    Token.TYPE_DESC},
                                {"as",     Token.TYPE_AS},
                                {"group",  Token.TYPE_GROUP},
                                {"having", Token.TYPE_HAVING},
                                {"connect", Token.TYPE_CONNECT},
                                {"case",   Token.TYPE_CASE},
                                {"when",   Token.TYPE_WHEN},
                                {"then",   Token.TYPE_THEN},
                                {"else",   Token.TYPE_ELSE},
                                {"end",    Token.TYPE_END},
                                {"is",     Token.TYPE_IS},
                                {"null",   Token.TYPE_NULL},
                                {"true",   Token.TYPE_TRUE},
                                {"false",   Token.TYPE_FALSE},
                                {"distinct",   Token.TYPE_DISTINCT},
                                {"over",   Token.TYPE_OVER},
                                {"on",     Token.TYPE_ON},
                                {"join",   Token.TYPE_JOIN},
                                {"inner",   Token.TYPE_INNER},
                                {"left",    Token.TYPE_LEFT},
                                {"right",   Token.TYPE_RIGHT},
                                {"outer",   Token.TYPE_OUTER},
                                {"full",    Token.TYPE_FULL},
                                {"within",   Token.TYPE_WITHIN},
                                {"partition",   Token.TYPE_PARTITION},
                                {"like",    Token.TYPE_LIKE},
                                {"limit",   Token.TYPE_LIMIT},
                            };
            
            for(Object[] arrInner:arr) {
                String keyword=String.valueOf(arrInner[0]);
                if(keyword.equalsIgnoreCase(text)) {
                    return Integer.parseInt(arrInner[1].toString());
                }
            }
            
            return Token.TYPE_TEXT;
        }
        
        private void addTextToList(String text) {
            int type=findTypeByText(text);
            addToken2List(text,type);
        }
        
        private void addToken2List(String text,int type) {
            if(text.trim().length()>0) {
                tokens.add(new Token(text,type));
            }
        }
        
        public void printTokens() {
            final String continuousStar = createRepeatedStr("-", 84);
            final String layout = "%-20s %-20s %-20s %-20s %s";
            StringBuilder sb = new StringBuilder();
    
            sb.append(String.format(layout, "Index", "Type No","Text","Type Desc","
    "));
            sb.append(continuousStar + "
    ");
            int index=0;
            for(Token token:tokens) {
                sb.append(String.format(layout, String.valueOf(index),String.valueOf(token.getType()), token.getText(),token.getTypeStr(),"
    "));
                index++;
            }
            
            System.out.println(sb.toString());
        }
        
        public List<Token> getTokens() {
            return tokens;
        }
        
        private static String createRepeatedStr(String seed, int n) {
            return String.join("", Collections.nCopies(n, seed));
        }
        
        private String pretreat(String raw) {
            return raw.trim()+" ";
        }
        
        public static void main(String[] args)  throws Exception{
            String sql=removeExtraSpace(readSqlFromFile("c:\temp\13.sql"));
            System.out.println(sql);
            new Lexer(sql).printTokens();
        }
        
        private static String readSqlFromFile(String filePath) throws Exception{
            StringBuilder sb=new StringBuilder();
            BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(filePath), "UTF-8"));  
            String line = null;  
            while( ( line = br.readLine() ) != null ) {
                sb.append(line);
            }
            br.close();  
            return sb.toString();
        }
        
        private static String removeExtraSpace(String raw) {
            return raw.replaceAll("\s{2,}", " ");
        }
    }

    Node:

    package com.heyang;
    
    import java.util.ArrayList;
    import java.util.Collections;
    import java.util.List;
    
    public class Node {
        private String kwSelect;
        private List<Field> fields;
        private String kwFrom;
        private List<Table> tables;
        private String kwWhere;
        private List<Condition> conditions;
        private String kwOrderby;
        private List<Order> orders;
        private int depth=0;
        
        public void addOrder(Order o) {
            if(orders==null) {
                orders=new ArrayList<Order>();
            }
            
            orders.add(o);
        }
        
        public void addCondition(Condition c) {
            if(conditions==null) {
                conditions=new ArrayList<Condition>();
            }
            
            conditions.add(c);
        }
        
        public String toString() {
            String tabs=getIndentSpace();
            
            StringBuilder sb=new StringBuilder();
            sb.append(tabs+kwSelect+"
    ");
            
            if(fields!=null) {
                List<String> ls=new ArrayList<String>();
                for(Field f:fields) {
                    ls.add(tabs+"    "+f.toString());
                }
                
                sb.append(String.join(",
    ", ls));
            }
            sb.append("
    ");
            sb.append(tabs+kwFrom+"
    ");
            
            if(tables!=null) {
                List<String> ls=new ArrayList<String>();
                for(Table tb:tables) {
                    ls.add(tabs+"    "+tb.toString()+"");
                }
                
                sb.append(String.join(",
    ", ls));
            }
            
            if(kwWhere!=null) {
                sb.append("
    ");
                sb.append(tabs+kwWhere+"
    ");
            }
            if(conditions!=null) {
                List<String> ls=new ArrayList<String>();
                for(Condition cd:conditions) {
                    ls.add(tabs+"    "+cd.toString()+"");
                }
                
                sb.append(String.join("
    ", ls));
            }
            
            if(kwOrderby!=null) {
                sb.append("
    ");
                sb.append(tabs+kwOrderby+"
    ");
            }
            if(orders!=null) {
                List<String> ls=new ArrayList<String>();
                for(Order od:orders) {
                    ls.add(tabs+"    "+od.toString()+"");
                }
                
                sb.append(String.join(",
    ", ls));
            }
            
            return sb.toString();
        }
        
        private String getIndentSpace() {
            return String.join("", Collections.nCopies(this.depth, "    "));
        }
        
        
        private void adjustDepth() {
            if(tables==null) {
                return;
            }
            for(Table tb:tables) {
                Node nd=tb.getTableNode();
                if(nd!=null) {
                    nd.depth=this.depth+1;
                    nd.adjustDepth();
                }
            }
            
            if(fields==null) {
                return;
            }
            for(Field fd:fields) {
                Node nd=fd.getColumnNode();
                if(nd!=null) {
                    nd.depth=this.depth+1;
                    nd.adjustDepth();
                }
            }
        }
        
        public void addTable(Table t) {
            if(tables==null) {
                tables=new ArrayList<Table>();
            }
            
            tables.add(t);
            adjustDepth();
        }
        
        public void addField(Field f) {
            if(fields==null) {
                fields=new ArrayList<Field>();
            }
            
            fields.add(f);
            adjustDepth();;
        }
        
        public void setKwSelect(String s) {
            this.kwSelect=s;
        }
    
        public String getKwFrom() {
            return kwFrom;
        }
    
        public void setKwFrom(String kwFrom) {
            this.kwFrom = kwFrom;
        }
    
        public String getKwSelect() {
            return kwSelect;
        }
    
        public String getKwWhere() {
            return kwWhere;
        }
    
        public void setKwWhere(String kwWhere) {
            this.kwWhere = kwWhere;
        }
    
        public String getKwOrderby() {
            return kwOrderby;
        }
    
        public void setKwOrderby(String kwOrderby) {
            this.kwOrderby = kwOrderby;
        }
    }

    TreeBuilder:

    package com.heyang;
    
    import java.util.List;
    
    public class TreeBuilder {
        private Node root;
        private List<Token> tokens;
        private int tokenIdx;
        
        public TreeBuilder(List<Token> tokens) throws Exception{
            this.tokens=tokens;
            this.tokenIdx=0;
            
            root=new Node();
            parseNode(root);
            
        }
        
        private void parseNode(Node parent) throws Exception{
            Token token;
            
            // select
            token=fetchToken();
            if(token.getType()!=Token.TYPE_SELECT) {
                throw new Exception("Expected:'Select' actual:"+token.getText()+" "+token);
            }
            parent.setKwSelect(token.getText());
            
            // find fields
            for(;;) {
                token=fetchToken();
                
                Field field=new Field();
                if(token.getType()==Token.TYPE_TEXT) {
                    String column=token.getText();
                    field.setColumn(column);
                }else if(token.getType()==Token.TYPE_OPEN_PARENTHESIS) {
                    Node columnNode=new Node();
                    field.setColumnNode(columnNode);
                    
                    parseNode(columnNode);
                    
                    token=fetchToken();
                    if(token.getType()!=Token.TYPE_CLOSE_PARENTHESIS) {
                        throw new Exception("Expected:')' actual:"+token.getText()+" "+token);
                    }
                }else {
                    throw new Exception("Expected:text/child query actual:"+token.getText()+" "+token);
                }
                
                String alias=null;            
                token=fetchToken();
                if(token.getType()==Token.TYPE_TEXT) {
                    alias=token.getText();
                }else if(token.getType()==Token.TYPE_COMMA) {
                    returnToken();
                }else if(token.getType()==Token.TYPE_AS) {
                    token=fetchToken();
                    if(token.getType()!=Token.TYPE_TEXT) {
                        throw new Exception("Expected:text actual:"+token.getText()+" "+token);
                    }
                    alias=token.getText();
                }else {
                    returnToken();
                }
                field.setAlias(alias);
                parent.addField(field);
                
                token=fetchToken();
                if(token.getType()!=Token.TYPE_COMMA) {
                    returnToken();
                    break;
                }
            }
            
            // from
            token=fetchToken();
            if(token.getType()!=Token.TYPE_FROM) {
                throw new Exception("Expected:'from' actual:"+token.getText()+" "+token);
            }
            parent.setKwFrom(token.getText());
            
            // find tables
            for(;;) {
                Node tableNode=new Node();
                Table table=new Table();
                table.setTableNode(tableNode);
                parent.addTable(table);
                
                token=fetchToken();
                if(token.getType()==Token.TYPE_TEXT) {
                    table.setTableName(token.getText());
                }else if(token.getType()==Token.TYPE_OPEN_PARENTHESIS) {
                    parseNode(tableNode);
                    
                    token=fetchToken();
                    if(token.getType()!=Token.TYPE_CLOSE_PARENTHESIS) {
                        throw new Exception("Expected:')' actual:"+token.getText()+" "+token);
                    }
                }
                
                token=fetchToken();
                if(token==null) {
                    return;
                }else if(token.getType()==Token.TYPE_TEXT) {
                    table.setAlias(token.getText());
                }else {
                    returnToken();
                }
                
                token=fetchToken();
                if(token==null) {
                    return;
                }else if(token.getType()!=Token.TYPE_COMMA) {
                    returnToken();
                    break;
                }
            }
            
            // where
            token=fetchToken();
            if(token==null) {
                return;
            }else if(token.getType()==Token.TYPE_WHERE) {
                parent.setKwWhere(token.getText());
            }else {
                returnToken();
                return;
            }
            
            // find conditions
            for(;;) {
                Condition cond=new Condition();
                parent.addCondition(cond);
                
                token=fetchToken();
                if(token.getType()==Token.TYPE_TEXT) {
                    cond.setLeft(token.getText());
                }else {
                    returnToken();
                    break;
                }
                
                token=fetchToken(); 
                if(token.getType()==Token.TYPE_EQUAL || token.getType()==Token.TYPE_LESSTHAN || token.getType()==Token.TYPE_GREATERTHAN) {
                    cond.setOprand(token.getText());
                }else {
                    throw new Exception("Expected:oprand actual:"+token.getText()+" "+token);
                }
                
                token=fetchToken();
                if(token.getType()==Token.TYPE_TEXT) {
                    cond.setRight(token.getText());
                }else {
                    throw new Exception("Expected:text actual:"+token.getText()+" "+token);
                }
                
                token=fetchToken();
                if(token==null) {
                    break;
                }else if(token.getType()==Token.TYPE_AND || token.getType()==Token.TYPE_OR) {
                    cond.setJoint(token.getText());
                }else {
                    returnToken();
                    break;
                }
            }
            
            // order by
            token=fetchToken();
            if(token==null) {
                return;
            }else if(token.getType()==Token.TYPE_ORDER) {
                String order=token.getText();
                
                token=fetchToken();
                if(token.getType()==Token.TYPE_BY) {
                    String by=token.getText();
                    parent.setKwOrderby(order+" "+by);
                }
                else {
                    throw new Exception("Expected:'by' actual:"+token.getText()+" "+token);
                }
                
            }else {
                returnToken();
                return;
            }
            
            // find orders
            for(;;) {
                Order order=new Order();
                parent.addOrder(order);
                
                token=fetchToken();
                if(token.getType()==Token.TYPE_TEXT) {
                    order.setColumn(token.getText());
                }else {
                    throw new Exception("Expected:text actual:"+token.getText()+" "+token);
                }
                
                token=fetchToken(); 
                if(token==null) {
                    return;
                }else if(token.getType()==Token.TYPE_ASC || token.getType()==Token.TYPE_DESC ) {
                    order.setAscDesc(token.getText());
                }else if(token.getType()==Token.TYPE_COMMA) {
                    returnToken();
                }else {
                    throw new Exception("Expected:'asc/desc/,' actual:"+token.getText()+" "+token);
                }
                
                token=fetchToken(); 
                if(token==null) {
                    return;
                }else if(token.getType()==Token.TYPE_COMMA) {
                    continue;
                }
            }
        }
        
        private Token fetchToken() {
            if(tokenIdx>=tokens.size()) {
                return null;
            }else {
                Token t=tokens.get(tokenIdx);
                tokenIdx++;
                return t;
            }        
        }
        
        private void returnToken() {
            if(tokenIdx>0) {
                tokenIdx--;
            }
        }
        
        public Node getRoot() {
            return root;
        }
    }

    统合类:

    package com.heyang;
    
    import com.heyang.util.BracketChecker;
    import com.heyang.util.CommonUtil;
    import com.heyang.util.Renderer;
    
    public class EntryPoint {
        public static void main(String[] args) {
            try {
                // Read context from file
                String text=CommonUtil.readTextFromFile("C:\hy\files\sql\10.sql");
                System.out.println("原文="+text);
                
                // Is brackets balanced
                BracketChecker checker=new BracketChecker();
                boolean isBalanced=checker.isBalanced(text);
                if(isBalanced==false) {
                    System.out.println(Renderer.paintBrown(checker.getErrMsg()));
                    return;
                }
                
                // lex text to tokens
                Lexer lex=new Lexer(text);
                //lex.printTokens();
                
                // Build tree
                TreeBuilder tb=new TreeBuilder(lex.getTokens());
                Node root=tb.getRoot();
                System.out.println("整理后文本=
    "+root);
                
            }catch(Exception ex) {
                System.out.println(Renderer.paintBrown(ex.getMessage()));
                ex.printStackTrace();
            }
        }
    }

    执行效果:

    原文=select name as name,birthday as b,column c from tc c,tb b,(select a1,a2,a3 from (select * from tbc) tbc) ta
    整理后文本=
    select
        name name,
        birthday b,
        column c
    from
        tc c,
        tb b,
        (
        select
            a1,
            a2,
            a3
        from
            (
            select
                *
            from
                tbc) tbc) ta

    --2020.05.27--

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  • 原文地址:https://www.cnblogs.com/heyang78/p/12974196.html
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