原创地址

转：(https://blog.csdn.net/MCJ_2017/article/details/81940167%E3%80%82)

修改之后的工具类

import java.util.HashSet;
import java.util.LinkedList;
import java.util.Set;
import java.util.StringTokenizer;public class SQLFormatterUtil {private static final Set<String> BEGIN_CLAUSES = new HashSet<>();private static final Set<String> END_CLAUSES = new HashSet<>();private static final Set<String> LOGICAL = new HashSet<>();private static final Set<String> QUANTIFIERS = new HashSet<>();private static final Set<String> DML = new HashSet<>();private static final Set<String> MISC = new HashSet<>();private static final String WHITESPACE = " \n\r\f\t";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");}static final String indentString = "    ";public static 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<Integer> parenCounts = new LinkedList<>();private LinkedList<Boolean> afterByOrFromOrSelects = new LinkedList<>();int indent = 0;StringBuilder result = new StringBuilder();StringTokenizer tokens;String lastToken;String token;String lcToken;private FormatProcess(String sql) {tokens = new StringTokenizer(sql,"()+*/-=<>'`\"[]," + WHITESPACE,true);}private String perform() {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;}}@SuppressWarnings({"UnnecessaryBoxing"})private void select() {out();indent++;newline();parenCounts.addLast(Integer.valueOf(parensSinceSelect));afterByOrFromOrSelects.addLast(Boolean.valueOf(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();afterValues = true;}@SuppressWarnings({"UnnecessaryUnboxing"})private void closeParen() {parensSinceSelect--;if (parensSinceSelect < 0) {indent--;parensSinceSelect = parenCounts.removeLast().intValue();afterByOrSetOrFromOrSelect = afterByOrFromOrSelects.removeLast().booleanValue();}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;}}}

其它方式

阿里druid的工具类

System.out.println(sql);
String resultSql = SQLUtils.format(sql, JdbcConstants.MYSQL);
System.out.println(resultSql);
String resultSqlLcase = SQLUtils.format(resultSql, JdbcConstants.HIVE, SQLUtils.DEFAULT_LCASE_FORMAT_OPTION);
System.out.println(resultSqlLcase);