Java tutorial
/* * Hibernate, Relational Persistence for Idiomatic Java * * License: GNU Lesser General Public License (LGPL), version 2.1 or later. * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>. */ package org.hibernate.engine.jdbc.internal; import java.util.HashSet; import java.util.LinkedList; import java.util.Locale; import java.util.Set; import java.util.StringTokenizer; import org.hibernate.internal.util.StringHelper; /** * Performs formatting of basic SQL statements (DML + query). * * @author Gavin King * @author Steve Ebersole */ public class BasicFormatterImpl implements Formatter { private static final Set<String> BEGIN_CLAUSES = new HashSet<String>(); private static final Set<String> END_CLAUSES = new HashSet<String>(); private static final Set<String> LOGICAL = new HashSet<String>(); private static final Set<String> QUANTIFIERS = new HashSet<String>(); private static final Set<String> DML = new HashSet<String>(); private static final Set<String> MISC = new HashSet<String>(); static { BEGIN_CLAUSES.add("left"); BEGIN_CLAUSES.add("right"); BEGIN_CLAUSES.add("inner"); BEGIN_CLAUSES.add("outer"); BEGIN_CLAUSES.add("group"); BEGIN_CLAUSES.add("order"); END_CLAUSES.add("where"); END_CLAUSES.add("set"); END_CLAUSES.add("having"); END_CLAUSES.add("from"); END_CLAUSES.add("by"); END_CLAUSES.add("join"); END_CLAUSES.add("into"); END_CLAUSES.add("union"); LOGICAL.add("and"); LOGICAL.add("or"); LOGICAL.add("when"); LOGICAL.add("else"); LOGICAL.add("end"); QUANTIFIERS.add("in"); QUANTIFIERS.add("all"); QUANTIFIERS.add("exists"); QUANTIFIERS.add("some"); QUANTIFIERS.add("any"); DML.add("insert"); DML.add("update"); DML.add("delete"); MISC.add("select"); MISC.add("on"); } private static final String INDENT_STRING = " "; private static final String INITIAL = System.lineSeparator() + INDENT_STRING; @Override public String format(String source) { return new FormatProcess(source).perform(); } private static class FormatProcess { boolean beginLine = true; boolean afterBeginBeforeEnd; boolean afterByOrSetOrFromOrSelect; boolean afterOn; boolean afterBetween; boolean afterInsert; int inFunction; int parensSinceSelect; private LinkedList<Integer> parenCounts = new LinkedList<Integer>(); private LinkedList<Boolean> afterByOrFromOrSelects = new LinkedList<Boolean>(); int indent = 1; StringBuilder result = new StringBuilder(); StringTokenizer tokens; String lastToken; String token; String lcToken; public FormatProcess(String sql) { tokens = new StringTokenizer(sql, "()+*/-=<>'`\"[]," + StringHelper.WHITESPACE, true); } public String perform() { result.append(INITIAL); while (tokens.hasMoreTokens()) { token = tokens.nextToken(); lcToken = token.toLowerCase(Locale.ROOT); if ("'".equals(token)) { String t; do { t = tokens.nextToken(); token += t; } // cannot handle single quotes while (!"'".equals(t) && tokens.hasMoreTokens()); } else if ("\"".equals(token)) { String t; do { t = tokens.nextToken(); token += t; } while (!"\"".equals(t) && tokens.hasMoreTokens()); } // SQL Server uses "[" and "]" to escape reserved words // see SQLServerDialect.openQuote and SQLServerDialect.closeQuote else if ("[".equals(token)) { String t; do { t = tokens.nextToken(); token += t; } while (!"]".equals(t) && tokens.hasMoreTokens()); } if (afterByOrSetOrFromOrSelect && ",".equals(token)) { commaAfterByOrFromOrSelect(); } else if (afterOn && ",".equals(token)) { commaAfterOn(); } else if ("(".equals(token)) { openParen(); } else if (")".equals(token)) { closeParen(); } else if (BEGIN_CLAUSES.contains(lcToken)) { beginNewClause(); } else if (END_CLAUSES.contains(lcToken)) { endNewClause(); } else if ("select".equals(lcToken)) { select(); } else if (DML.contains(lcToken)) { updateOrInsertOrDelete(); } else if ("values".equals(lcToken)) { values(); } else if ("on".equals(lcToken)) { on(); } else if (afterBetween && lcToken.equals("and")) { misc(); afterBetween = false; } else if (LOGICAL.contains(lcToken)) { logical(); } else if (isWhitespace(token)) { white(); } else { misc(); } if (!isWhitespace(token)) { lastToken = lcToken; } } return result.toString(); } private void commaAfterOn() { out(); indent--; newline(); afterOn = false; afterByOrSetOrFromOrSelect = true; } private void commaAfterByOrFromOrSelect() { out(); newline(); } private void logical() { if ("end".equals(lcToken)) { indent--; } newline(); out(); beginLine = false; } private void on() { indent++; afterOn = true; newline(); out(); beginLine = false; } private void misc() { out(); if ("between".equals(lcToken)) { afterBetween = true; } if (afterInsert) { newline(); afterInsert = false; } else { beginLine = false; if ("case".equals(lcToken)) { indent++; } } } private void white() { if (!beginLine) { result.append(" "); } } private void updateOrInsertOrDelete() { out(); indent++; beginLine = false; if ("update".equals(lcToken)) { newline(); } if ("insert".equals(lcToken)) { afterInsert = true; } } private void select() { out(); indent++; newline(); parenCounts.addLast(parensSinceSelect); afterByOrFromOrSelects.addLast(afterByOrSetOrFromOrSelect); parensSinceSelect = 0; afterByOrSetOrFromOrSelect = true; } private void out() { result.append(token); } private void endNewClause() { if (!afterBeginBeforeEnd) { indent--; if (afterOn) { indent--; afterOn = false; } newline(); } out(); if (!"union".equals(lcToken)) { indent++; } newline(); afterBeginBeforeEnd = false; afterByOrSetOrFromOrSelect = "by".equals(lcToken) || "set".equals(lcToken) || "from".equals(lcToken); } private void beginNewClause() { if (!afterBeginBeforeEnd) { if (afterOn) { indent--; afterOn = false; } indent--; newline(); } out(); beginLine = false; afterBeginBeforeEnd = true; } private void values() { indent--; newline(); out(); indent++; newline(); } private void closeParen() { parensSinceSelect--; if (parensSinceSelect < 0) { indent--; parensSinceSelect = parenCounts.removeLast(); afterByOrSetOrFromOrSelect = afterByOrFromOrSelects.removeLast(); } if (inFunction > 0) { inFunction--; out(); } else { if (!afterByOrSetOrFromOrSelect) { indent--; newline(); } out(); } beginLine = false; } private void openParen() { if (isFunctionName(lastToken) || inFunction > 0) { inFunction++; } beginLine = false; if (inFunction > 0) { out(); } else { out(); if (!afterByOrSetOrFromOrSelect) { indent++; newline(); beginLine = true; } } parensSinceSelect++; } private static boolean isFunctionName(String tok) { if (tok == null || tok.length() == 0) { return false; } final char begin = tok.charAt(0); final boolean isIdentifier = Character.isJavaIdentifierStart(begin) || '"' == begin; return isIdentifier && !LOGICAL.contains(tok) && !END_CLAUSES.contains(tok) && !QUANTIFIERS.contains(tok) && !DML.contains(tok) && !MISC.contains(tok); } private static boolean isWhitespace(String token) { return StringHelper.WHITESPACE.contains(token); } private void newline() { result.append(System.lineSeparator()); for (int i = 0; i < indent; i++) { result.append(INDENT_STRING); } beginLine = true; } } }