libformula 可能是一个不错的起点。这是一个概念证明:
$ excel 'TRIM(" abc 123 ")'
abc 123
excel 是这个简单的 shell 脚本:
#!/bin/sh
java -cp /usr/share/java/commons-logging.jar:libformula/demo:libbase/dist/libbase-6.1-SNAPSHOT.jar:libformula/dist/libformula-6.1-SNAPSHOT.jar:/home/cwarden/git/excel/src org.xerus.excel.Excel "$1"
而org.xerus.excel.Excel 从 argv 中获取一个字符串并将其作为公式计算:
package org.xerus.excel;
import org.pentaho.reporting.libraries.formula.EvaluationException;
import org.pentaho.reporting.libraries.formula.Formula;
import org.pentaho.reporting.libraries.formula.DefaultFormulaContext;
import org.pentaho.reporting.libraries.formula.parser.ParseException;
public class Excel {
public static void main(final String[] args) throws ParseException, EvaluationException {
final Formula f = new Formula(args[0]);
f.initialize(new DefaultFormulaContext());
final Object o = f.evaluate();
System.out.println(o);
}
}
libformula 包含一个演示程序org.pentaho.reporting.libraries.formula.demo.PrintAllFunctions,它会打印出所有支持的函数:
Category User-Defined
ARRAYCONCATENATE, ARRAYCONTAINS, ARRAYLEFT, ARRAYMID, CSVARRAY, CSVTEXT, NORMALIZEARRAY, NULL, PARSEDATE, SEQUENCEQUOTER
Category Information
CHOOSE, COUNT, COUNTA, COUNTBLANK, ERROR, HASCHANGED, INDEX, ISBLANK, ISERR, ISERROR, ISEVEN, ISLOGICAL, ISNA, ISNONTEXT, ISNUMBER, ISODD, ISREF, ISTEXT, LOOKUP, NA, VALUE
Category Rounding
INT
Category Mathematical
ABS, ACOS, ACOSH, ASIN, ATAN, ATAN2, AVERAGE, AVERAGEA, COS, EVEN, EXP, LN, LOG10, MAX, MAXA, MIN, MINA, MOD, N, ODD, PI, POWER, SIN, SQRT, SUM, SUMA, VAR
Category Text
ARRAYRIGHT, ASC, CHAR, CLEAN, CODE, CONCATENATE, EXACT, FIND, FIXED, FIXED, LEFT, LEN, LOWER, MESSAGE, MID, PROPER, REPLACE, REPT, RIGHT, SEARCH, STRINGCOUNT, SUBSTITUTE, T, TEXT, TRIM, UNICHAR, UNICODE, UPPER, URLENCODE
Category Date/Time
DATE, DATEDIF, DATETIMEVALUE, DATEVALUE, DAY, DAYS, HOUR, MINUTE, MONTH, MONTHEND, NOW, PREVWEEKDAY, SECOND, TIME, TIMEVALUE, TODAY, WEEKDAY, YEAR, YESTERDAY
Category Logical
AND, FALSE, IF, IFNA, NOT, OR, TRUE, XOR
Category Database
BEGINSWITH, CONTAINS, ENDSWITH, EQUALS, IN, LIKE