package com.github.ltsopensource.store.jdbc;
import java.util.*;
/**
* 格式化SQL
* 来自hibernate更改
*
* @author Robert HG (254963746@qq.com) on 3/9/16.
*/
public class SQLFormatter {
private static final String WHITESPACE = " \n\r\f\t";
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>();
private static final Set<String> UPPER_CASE = 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("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");
//MISC.add("values");
// 这个是mysql关键字列表, 会转化为大写 (需要的时候添加)
UPPER_CASE.addAll(Arrays.asList("select", "insert", "update", "delete", "on", "left", "right", "inner", "outer", "group",
"order", "where", "set", "having", "join", "from", "by", "join", "into",
"union", "and", "or", "when", "else", "end", "in", "all", "exists", "if", "some", "any", "distinct", "count", "sum", "as", "asc", "desc", "between",
"alter", "table", "else", "elseif", "index", "ignore", "limit", "like", "offset"
));
}
String indentString = " ";
String initial = "\n ";
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<Integer> parenCounts = new LinkedList<Integer>();
private LinkedList<Boolean> afterByOrFromOrSelects = new LinkedList<Boolean>();
int indent = 1;
StringBuffer result = new StringBuffer();
StringTokenizer tokens;
String lastToken;
String token;
String lcToken;
public SQLFormatter(String sql) {
tokens = new StringTokenizer(
sql,
"()+*/-=<>'`\"[]," + WHITESPACE,
true
);
}
public SQLFormatter setInitialString(String initial) {
this.initial = initial;
return this;
}
public SQLFormatter setIndentString(String indent) {
this.indentString = indent;
return this;
}
public String format() {
result.append(initial);
while (tokens.hasMoreTokens()) {
token = tokens.nextToken();
lcToken = token.toLowerCase();
if ("'".equals(token)) {
String t;
do {
t = tokens.nextToken();
token += t;
}
while (!"'".equals(t) && tokens.hasMoreTokens()); // cannot handle single quotes
} else if ("\"".equals(token)) {
String t;
do {
t = tokens.nextToken();
token += t;
}
while (!"\"".equals(t));
}
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() {
if (UPPER_CASE.contains(token.toLowerCase())) {
token = token.toUpperCase();
}
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();
afterValues = true;
}
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) {
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 WHITESPACE.contains(token);
}
private void newline() {
result.append("\n");
for (int i = 0; i < indent; i++) {
result.append(indentString);
}
beginLine = true;
}
public static String format(String sql) {
try {
return new SQLFormatter(sql).format();
} catch (Throwable t) {
return sql;
}
}
}