Java正则替换一例

Java正则替换一例

　　不区分大小写，换行支持。。。，一个SQL工具要用这个代码。

　　package com.lavasoft.regtest;

　　import java.util.regex.Matcher;

　　import java.util.regex.Pattern;

　　/**

　　* 正则表达式SQL工具

　　*

　　* @author leizhimin 2010-5-18 10:34:34

　　*/

　　public class RegexToolkit {

　　//        private static final Pattern p_wellsql = Pattern.compile("\\s+?where\\s*?and\\s+?", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE);

　　private static final Pattern p_wellsql = Pattern.compile("(?i)(?m)\\s+?where\\s*?and\\s+?");

　　public static String genWellSQL(String badSQL) {

　　Matcher m = p_wellsql.matcher(badSQL);

　　return m.replaceAll(" where ");

　　}

　　public static void main(String[] args) {

　　String badsql = "select x.subs_level_id, count(x.logdataid)\n" +

　　"    from (select a.*\n" +

　　"                    from qm_subject_mining a\n" +

　　"\t Where \n" +

　　"\t     aND a.orgid = 901\n" +

　　"                 order by a.subs_level_id, a.usersatisfy, a.callstarttime desc) x\n" +

　　" WHere And rownum <= 30\n" +

　　" group by subs_level_id;";

　　String wellsql = genWellSQL(badsql);

　　System.out.println("替换前SQL：\n" + badsql);

　　System.out.println("替换后SQL：\n" + wellsql);

　　}

　　}

　　运行结果：

　　替换前SQL：

　　select x.subs_level_id, count(x.logdataid)

　　from (select a.*

　　from qm_subject_mining a

　　Where

　　aND a.orgid = 901

　　order by a.subs_level_id, a.usersatisfy, a.callstarttime desc) x

　　WHere And rownum <= 30

　　group by subs_level_id;

　　替换后SQL：

　　select x.subs_level_id, count(x.logdataid)

　　from (select a.*

　　from qm_subject_mining a where a.orgid = 901

　　order by a.subs_level_id, a.usersatisfy, a.callstarttime desc) x where rownum <= 30

　　group by subs_level_id;

　　Process finished with exit code 0

　　注意：一下两行代码是等价的。

　　private static final Pattern p_wellsql = Pattern.compile("\\s+?where\\s*?and\\s+?", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE);

　　private static final Pattern p_wellsql = Pattern.compile("(?i)(?m)\\s+?where\\s*?and\\s+?");