StringUtils.java

package org.openstack.atlas.util.ca;

import java.io.UnsupportedEncodingException;
import java.util.Collection;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.openstack.atlas.util.ca.primitives.RsaConst;

public class StringUtils {

    private static final String USASCII = "US-ASCII";
    private static final int PAGESIZE = 4096;

    public static String displayParsedInt(String strIn) {
        try {
            int i = Integer.parseInt(strIn);
            return String.format("%d", i);
        } catch (NumberFormatException ex) {
            return "INVALID";
        }
    }

    // Coulden't find a default library function to do this. :(
    // It iterates the string character per caracher and builds a new one so
    // Its like really slow. :(
    public static String escape_html(String html) {
        StringBuilder sb = new StringBuilder(RsaConst.PAGESIZE);
        char ch;
        int len = html.length();
        int i;
        for (i = 0; i < len; i++) {
            ch = html.charAt(i);
            switch (ch) {
                case ' ':
                    sb.append(" ");
                    break;
                case '<':
                    sb.append("<");
                    break;
                case '>':
                    sb.append(">");
                    break;
                case '"':
                    sb.append(""");
                    break;
                case '&':
                    sb.append("&");
                    break;
                case '\n':
                    sb.append("<br/>");
                    break;
                default:
                    sb.append(ch);
                    break;
            }
        }
        return sb.toString();
    }

    // Got tired of spelling ExtendedStackTrace
    public static String getEST(Throwable th) {
        return getExtendedStackTrace(th);
    }

    public static String getExtendedStackTrace(Throwable th) {
        Throwable t;
        StringBuilder sb = new StringBuilder(RsaConst.PAGESIZE);
        Exception currEx;
        String msg;

        t = th;
        while (t != null) {
            if (t instanceof Exception) {
                currEx = (Exception) t;
                sb.append(String.format("\"%s\":\"%s\"\n", currEx.getClass().getName(), currEx.getMessage()));
                for (StackTraceElement se : currEx.getStackTrace()) {
                    sb.append(String.format("%s\n", se.toString()));
                }
                sb.append("\n");
                t = t.getCause();
            }
        }
        return sb.toString();
    }

    public static <T> String joinString(Collection<T> objects, String delim) {
        StringBuilder sb = new StringBuilder();
        Object[] oarray = objects.toArray();
        int nobjects = oarray.length;
        if (nobjects == 0) {
            return "";
        }
        for (int i = 0; i < nobjects - 1; i++) {
            sb.append(String.format("%s%s", oarray[i].toString(), delim));
        }
        sb.append(String.format("%s", oarray[nobjects - 1]));
        return sb.toString();
    }

    public static String asciiString(byte[] asciiBytes) {
        if(asciiBytes == null){
            return "";
        }
        try {
            return new String(asciiBytes, USASCII);
        } catch (UnsupportedEncodingException ex) {
            return null; // Impossable exception
        }
    }

    public static byte[] asciiBytes(String asciiStr) {
        byte[] out = null;
        if(asciiStr==null){
            return new byte[0];
        }
        try {
            out = asciiStr.getBytes(USASCII);
            return out;
        } catch (UnsupportedEncodingException ex) {
            // Impossable Exception as Java Spec says all Implementations will
            // support US-ASCII. But incase the impossible does happen
            // return null
            return out;
        }
    }

    // checks if the strings are equal but will conclude the strings
    // are not equal if either is null.
    public static boolean strEquals(String a, String b) {
        if (a == null || b == null) {
            return false;
        } else {
            return a.equals(b);
        }
    }

    // LineWrapper for jython encodeing of Strings
    public static String lineWrap(String strIn,int cols){
        StringBuilder sb = new StringBuilder(PAGESIZE);
        char[] strArray = strIn.toCharArray();
        int chrsLeftToWrite = strArray.length;
        int offset = 0;
        while(chrsLeftToWrite > 0){
            int nChrs = (chrsLeftToWrite<cols)?chrsLeftToWrite:cols;
            sb.append(strArray, offset, nChrs);
            offset += nChrs;
            chrsLeftToWrite -= nChrs;
            if(chrsLeftToWrite>0){
                sb.append('\n');
            }
        }
        return sb.toString();
    }
}