package com.util;

import java.util.HashSet;
import java.util.LinkedList;
import java.util.Set;
import java.util.StringTokenizer;

public class BasicFormatterImpl
{
  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 final String indentString = "    ";
  static final String initial = "\n    ";

  public String format(String source)
  {
    return new FormatProcess(source).perform().trim() ;
  }

  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"); } 
  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<Integer>();
    private LinkedList<Boolean> afterByOrFromOrSelects = new LinkedList<Boolean>(); 
    
    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)) {
          String t;
          do { t = this.tokens.nextToken();
            this.token += t;
          }
          while ((!"'".equals(t)) && (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 (BasicFormatterImpl.BEGIN_CLAUSES.contains(this.lcToken)) {
          beginNewClause();
        }
        else if (BasicFormatterImpl.END_CLAUSES.contains(this.lcToken)) {
          endNewClause();
        }
        else if ("select".equals(this.lcToken)) {
          select();
        }
        else if (BasicFormatterImpl.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 (BasicFormatterImpl.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))
        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) && (!BasicFormatterImpl.LOGICAL.contains(tok)) && (!BasicFormatterImpl.END_CLAUSES.contains(tok)) && (!BasicFormatterImpl.QUANTIFIERS.contains(tok)) && (!BasicFormatterImpl.DML.contains(tok)) && (!BasicFormatterImpl.MISC.contains(tok));
    }

    private static boolean isWhitespace(String token)
    {
      return " \n\r\f\t".indexOf(token) >= 0;
    }

    private void newline() {
      this.result.append("\n");
      for (int i = 0; i < this.indent; i++) {
        this.result.append("    ");
      }
      this.beginLine = true;
    }
  }
}

	System.out.println( new BasicFormatterImpl().format("select dd,dd,ss from ta1  group by dd order by createtime desc limit 3 ") ) ;
	

Hibernate格式化sql语句实体类 BasicFormatterImpl 源码