UnicodeEscapeWriter.java

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package org.mule.devkit.model.code.util;

import java.io.FilterWriter;
import java.io.IOException;
import java.io.Writer;

/**
 * {@link java.io.Writer} that escapes non US-ASCII characters into
 * Java Unicode escape \\uXXXX.
 * <p/>
 * This process is necessary if the method names or field names
 * contain non US-ASCII characters.
 *
 * @author Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
 */
public class UnicodeEscapeWriter extends FilterWriter {

    public UnicodeEscapeWriter(Writer next) {
        super(next);
    }

    public final void write(int ch) throws IOException {
        if (!requireEscaping(ch)) {
            out.write(ch);
        } else {
            // need to escape
            out.write("\\u");
            String s = Integer.toHexString(ch);
            for (int i = s.length(); i < 4; i++) {
                out.write('0');
            }
            out.write(s);
        }
    }

    /**
     * Can be overrided. Return true if the character
     * needs to be escaped.
     */
    protected boolean requireEscaping(int ch) {
        if (ch >= 128) {
            return true;
        }

        // control characters
        if (ch < 0x20 && " \t\r\n".indexOf(ch) == -1) {
            return true;
        }

        return false;
    }

    public final void write(char[] buf, int off, int len) throws IOException {
        for (int i = 0; i < len; i++) {
            write(buf[off + i]);
        }
    }

    public final void write(char[] buf) throws IOException {
        write(buf, 0, buf.length);
    }

    public final void write(String buf, int off, int len) throws IOException {
        write(buf.toCharArray(), off, len);
    }

    public final void write(String buf) throws IOException {
        write(buf.toCharArray(), 0, buf.length());
    }

}