SQL格式化功能（JAVA代码）

package format; import java.util.HashSet; import java.util.LinkedList; import java.util.Set; import java.util.StringTokenizer; public class SqlFormatter{ private static final Set BEGIN_CLAUSES = new HashSet(); private static final Set END_CLAUSES = new HashSet(); private static final Set LOGICAL = new HashSet(); private static final Set QUANTIFIERS = new HashSet(); private static final Set DML = new HashSet(); private static final Set MISC = new HashSet(); static final String indentString = " "; static final String initial = "\n "; 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("join"); 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"); } public String format(String source) { return new FormatProcess(source).perform(); } private static class FormatProcess { boolean beginLine = true; boolean afterBeginBeforeEnd = false; boolean afterByOrSetOrFromOrSelect = false; boolean afterValues = false; boolean afterOn = false; boolean afterBetween = false; boolean afterInsert = false; int inFunction = 0; int parensSinceSelect = 0; private LinkedList parenCounts = new LinkedList(); private LinkedList afterByOrFromOrSelects = new LinkedList(); int indent = 1; StringBuffer result = new StringBuffer(); StringTokenizer tokens; String lastToken; String token; String lcToken; public FormatProcess(String sql) { this.tokens = new StringTokenizer(sql, "()+*/-=<>'`\"[], \n\r\f\t", true); } public String perform() { this.result.append("\n "); while (this.tokens.hasMoreTokens()) { this.token = this.tokens.nextToken(); this.lcToken = this.token.toLowerCase(); if ("'".equals(this.token)) { do { String t = this.tokens.nextToken(); this.token += t; if ("'".equals(t)) break; } while (this.tokens.hasMoreTokens()); } else if ("\"".equals(this.token)) { String t; do { t = this.tokens.nextToken(); this.token += t; } while (!"\"".equals(t)); } if ((this.afterByOrSetOrFromOrSelect) && (",".equals(this.token))) { commaAfterByOrFromOrSelect(); } else if ((this.afterOn) && (",".equals(this.token))) { commaAfterOn(); } else if ("(".equals(this.token)) { openParen(); } else if (")".equals(this.token)) { closeParen(); } else if (SqlFormatter.BEGIN_CLAUSES.contains(this.lcToken)) { beginNewClause(); } else if (SqlFormatter.END_CLAUSES.contains(this.lcToken)) { endNewClause(); } else if ("select".equals(this.lcToken)) { select(); } else if (SqlFormatter.DML.contains(this.lcToken)) { updateOrInsertOrDelete(); } else if ("values".equals(this.lcToken)) { values(); } else if ("on".equals(this.lcToken)) { on(); } else if ((this.afterBetween) && (this.lcToken.equals("and"))) { misc(); this.afterBetween = false; } else if (SqlFormatter.LOGICAL.contains(this.lcToken)) { logical(); } else if (isWhitespace(this.token)) { white(); } else { misc(); } if (!isWhitespace(this.token)) { this.lastToken = this.lcToken; } } return this.result.toString(); } private void commaAfterOn() { out(); this.indent -= 1; newline(); this.afterOn = false; this.afterByOrSetOrFromOrSelect = true; } private void commaAfterByOrFromOrSelect() { out(); newline(); } private void logical() { if ("end".equals(this.lcToken)) { this.indent -= 1; } newline(); out(); this.beginLine = false; } private void on() { this.indent += 1; this.afterOn = true; newline(); out(); this.beginLine = false; } private void misc() { out(); if ("between".equals(this.lcToken)) { this.afterBetween = true; } if (this.afterInsert) { newline(); this.afterInsert = false; } else { this.beginLine = false; if ("case".equals(this.lcToken)) this.indent += 1; } } private void white() { if (!this.beginLine) this.result.append(" "); } private void updateOrInsertOrDelete() { out(); this.indent += 1; this.beginLine = false; if ("update".equals(this.lcToken)) { newline(); } if ("insert".equals(this.lcToken))/* 272 */ this.afterInsert = true; } private void select() { out(); this.indent += 1; newline(); this.parenCounts.addLast(new Integer(this.parensSinceSelect)); this.afterByOrFromOrSelects.addLast(Boolean.valueOf(this.afterByOrSetOrFromOrSelect)); this.parensSinceSelect = 0; this.afterByOrSetOrFromOrSelect = true; } private void out() { this.result.append(this.token); } private void endNewClause() { if (!this.afterBeginBeforeEnd) { this.indent -= 1; if (this.afterOn) { this.indent -= 1; this.afterOn = false; } newline(); } out(); if (!"union".equals(this.lcToken)) { this.indent += 1; } newline(); this.afterBeginBeforeEnd = false; this.afterByOrSetOrFromOrSelect = (("by".equals(this.lcToken)) || ("set".equals(this.lcToken)) || ("from".equals(this.lcToken))); } private void beginNewClause() { if (!this.afterBeginBeforeEnd) { if (this.afterOn) { this.indent -= 1; this.afterOn = false; } this.indent -= 1; newline(); } out(); this.beginLine = false; this.afterBeginBeforeEnd = true; } private void values() { this.indent -= 1; newline(); out(); this.indent += 1; newline(); this.afterValues = true; } private void closeParen() { this.parensSinceSelect -= 1; if (this.parensSinceSelect < 0) { this.indent -= 1; this.parensSinceSelect = ((Integer) this.parenCounts.removeLast()).intValue(); this.afterByOrSetOrFromOrSelect = ((Boolean) this.afterByOrFromOrSelects.removeLast()).booleanValue(); } if (this.inFunction > 0) { this.inFunction -= 1; out(); } else { if (!this.afterByOrSetOrFromOrSelect) { this.indent -= 1; newline(); } out(); } this.beginLine = false; } private void openParen() { if ((isFunctionName(this.lastToken)) || (this.inFunction > 0)) { this.inFunction += 1; } this.beginLine = false; if (this.inFunction > 0) { out(); } else { out(); if (!this.afterByOrSetOrFromOrSelect) { this.indent += 1; newline(); this.beginLine = true; } } this.parensSinceSelect += 1; } private static boolean isFunctionName(String tok) { char begin = tok.charAt(0); boolean isIdentifier = (Character.isJavaIdentifierStart(begin)) || ('"' == begin); return (isIdentifier) && (!SqlFormatter.LOGICAL.contains(tok)) && (!SqlFormatter.END_CLAUSES.contains(tok)) && (!SqlFormatter.QUANTIFIERS.contains(tok)) && (!SqlFormatter.DML.contains(tok)) && (!SqlFormatter.MISC.contains(tok)); } private static boolean isWhitespace(String token) { return " \n\r\f\t".indexOf(token) >= 0; } private void newline() { this.result.append("\n");