Java example source code file (UtfHelpper.java)

This example Java source code file (UtfHelpper.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

ioexception, map, outputstream, string, utfhelpper, util

The UtfHelpper.java Java example source code

/*
 * reserved comment block
 * DO NOT REMOVE OR ALTER!
 */
/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.sun.org.apache.xml.internal.security.c14n.implementations;

import java.io.IOException;
import java.io.OutputStream;
import java.util.Map;

public class UtfHelpper {

    static final void writeByte(
        final String str,
        final OutputStream out,
        Map<String, byte[]> cache
    ) throws IOException {
        byte[] result = cache.get(str);
        if (result == null) {
            result = getStringInUtf8(str);
            cache.put(str, result);
        }

        out.write(result);
    }

    static final void writeCharToUtf8(final char c, final OutputStream out) throws IOException {
        if (c < 0x80) {
            out.write(c);
            return;
        }
        if ((c >= 0xD800 && c <= 0xDBFF) || (c >= 0xDC00 && c <= 0xDFFF)) {
            //No Surrogates in sun java
            out.write(0x3f);
            return;
        }
        int bias;
        int write;
        char ch;
        if (c > 0x07FF) {
            ch = (char)(c>>>12);
            write = 0xE0;
            if (ch > 0) {
                write |= (ch & 0x0F);
            }
            out.write(write);
            write = 0x80;
            bias = 0x3F;
        } else {
            write = 0xC0;
            bias = 0x1F;
        }
        ch = (char)(c>>>6);
        if (ch > 0) {
            write |= (ch & bias);
        }
        out.write(write);
        out.write(0x80 | ((c) & 0x3F));

    }

    static final void writeStringToUtf8(
        final String str,
        final OutputStream out
    ) throws IOException{
        final int length = str.length();
        int i = 0;
        char c;
        while (i < length) {
            c = str.charAt(i++);
            if (c < 0x80)  {
                out.write(c);
                continue;
            }
            if ((c >= 0xD800 && c <= 0xDBFF) || (c >= 0xDC00 && c <= 0xDFFF)) {
                //No Surrogates in sun java
                out.write(0x3f);
                continue;
            }
            char ch;
            int bias;
            int write;
            if (c > 0x07FF) {
                ch = (char)(c>>>12);
                write = 0xE0;
                if (ch > 0) {
                    write |= (ch & 0x0F);
                }
                out.write(write);
                write = 0x80;
                bias = 0x3F;
            } else {
                write = 0xC0;
                bias = 0x1F;
            }
            ch = (char)(c>>>6);
            if (ch > 0) {
                write |= (ch & bias);
            }
            out.write(write);
            out.write(0x80 | ((c) & 0x3F));

        }

    }

    public static final byte[] getStringInUtf8(final String str) {
        final int length = str.length();
        boolean expanded = false;
        byte[] result = new byte[length];
        int i = 0;
        int out = 0;
        char c;
        while (i < length) {
            c = str.charAt(i++);
            if (c < 0x80) {
                result[out++] = (byte)c;
                continue;
            }
            if ((c >= 0xD800 && c <= 0xDBFF) || (c >= 0xDC00 && c <= 0xDFFF)) {
                //No Surrogates in sun java
                result[out++] = 0x3f;
                continue;
            }
            if (!expanded) {
                byte newResult[] = new byte[3*length];
                System.arraycopy(result, 0, newResult, 0, out);
                result = newResult;
                expanded = true;
            }
            char ch;
            int bias;
            byte write;
            if (c > 0x07FF) {
                ch = (char)(c>>>12);
                write = (byte)0xE0;
                if (ch > 0) {
                    write |= (ch & 0x0F);
                }
                result[out++] = write;
                write = (byte)0x80;
                bias = 0x3F;
            } else {
                write = (byte)0xC0;
                bias = 0x1F;
            }
            ch = (char)(c>>>6);
            if (ch > 0) {
                write |= (ch & bias);
            }
            result[out++] = write;
            result[out++] = (byte)(0x80 | ((c) & 0x3F));
        }
        if (expanded) {
            byte newResult[] = new byte[out];
            System.arraycopy(result, 0, newResult, 0, out);
            result = newResult;
        }
        return result;
    }

}