Java Script toSci(BigDecimal bd, int sf)

Description

to Sci

License

Mozilla Public License

Declaration

public static String toSci(BigDecimal bd, int sf) 

Method Source Code

//package com.java2s;
/** This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *//* ww w.j  av  a2 s  .c om*/

import java.text.*;
import java.math.*;
import javax.script.*;

public class Main {
    private static final ScriptEngine engine = (new ScriptEngineManager()).getEngineByName("javascript");

    public static String toSci(BigDecimal bd, int sf) {
        Double x = bd.doubleValue();
        if (x.equals(Double.POSITIVE_INFINITY) || x.equals(Double.NEGATIVE_INFINITY)) {
            return x.toString();
        } else {
            try {
                return toString(
                        Double.parseDouble(engine.eval("Number(" + x + ").toPrecision(" + sf + ")").toString()));
            } catch (Exception ex) {
                return toFix(bd, 15);
            }
        }
    }

    public static String toString(double x) {
        String str = x + "";
        if (str.matches(".*\\.0")) {
            str = str.substring(0, str.indexOf("."));
        }
        return str;
    }

    public static double toFix(double x, int dp) {
        String format = "";
        for (int i = 0; i < dp; i++) {
            format = format + "#";
        }
        return Double.parseDouble((new DecimalFormat("#0." + format)).format(x));
    }

    public static String toFix(BigDecimal x, int dp) {
        String format = "";
        for (int i = 0; i < dp; i++) {
            format = format + "#";
        }
        return (new DecimalFormat("#0." + format)).format(x);
    }
}

Related

1. getScriptCompileMsg(ScriptException ex)
2. getSpParamOfWeiboLogin(String pwd, String servicetime, String nonce)
3. removeScript(String name)
4. runScript(final String script)
5. toMap(ScriptObjectMirror som, Class type)