Java String Parse tryParse(String input, Object defVal)

Description

try Parse

License

Apache License

Declaration

public static Object tryParse(String input, Object defVal) 

Method Source Code

//package com.java2s;
//License from project: Apache License 

public class Main {
    public static Object tryParse(String input, Object defVal) {
        if (input.equals("null"))
            return defVal;

        if (defVal instanceof Boolean) {
            return Boolean.valueOf(input);
        } else {/*from  w  w w.j  a va 2  s . c om*/
            if (input.equals("true"))
                return true;
            if (input.equals("false"))
                return false;
        }

        if ("[]".equals(input) && (defVal != null) && defVal.getClass().isArray())
            return defVal;

        try {
            return Integer.parseInt(input);
        } catch (NumberFormatException e) {
            if ((defVal instanceof Number) && !(defVal instanceof Double || defVal instanceof Float))
                throw e; // integer number expected but couldn't be parsed
        }

        try {
            return Double.parseDouble(input);
        } catch (NumberFormatException e) {
            if (defVal instanceof Number)
                throw e; // number expected but couldn't be parsed
        }

        try {
            return parseArrayOfInts(input);
        } catch (NumberFormatException e) {
            if (defVal instanceof int[])
                throw e; // int array expected
        }

        try {
            return parseArrayOfDoubles(input);
        } catch (NumberFormatException e) {
            if (defVal instanceof double[])
                throw e; // double array expected
        }

        return input;
    }

    public static int[] parseArrayOfInts(String input) {
        if (!(input.startsWith("[") && input.endsWith("]")))
            throw new NumberFormatException("Array should be enclosed in square brackets");
        String[] parts = input.substring(1, input.length() - 1).split(",");
        int[] res = new int[parts.length];
        for (int i = 0; i < parts.length; i++)
            res[i] = Integer.parseInt(parts[i].trim());
        return res;
    }

    public static double[] parseArrayOfDoubles(String input) {
        if (!(input.startsWith("[") && input.endsWith("]")))
            throw new NumberFormatException("Array should be enclosed in square brackets");
        String[] parts = input.substring(1, input.length() - 1).split(",");
        double[] res = new double[parts.length];
        for (int i = 0; i < parts.length; i++)
            res[i] = Double.parseDouble(parts[i].trim());
        return res;
    }
}

Related

1. tryParse(String pValue)
2. tryParse(String s, double d)
3. tryParse(String s, int i)
4. tryParse(String s, Integer defaultValue)