1 /*

     2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package com.sun.tools.sjavac.server;

    27 

    28 import java.io.FilterWriter;

    29 import java.io.IOException;

    30 import java.io.Writer;

    31 

    32 /**

    33  * Inserts {@literal prefix} in front of each line written.

    34  *

    35  * A line is considered to be terminated by any one of a line feed, a carriage

    36  * return, or a carriage return followed immediately by a line feed.

    37  */

    38 public class LinePrefixFilterWriter extends FilterWriter {

    39 

    40     private final String prefix;

    41     private boolean atBeginningOfLine = true;

    42     private char lastChar = '\0';

    43 

    44     protected LinePrefixFilterWriter(Writer out, String prefix) {

    45         super(out);

    46         this.prefix = prefix;

    47     }

    48 

    49     @Override

    50     public void write(String str, int off, int len) throws IOException {

    51         for (int i = 0; i < len; i++) {

    52             write(str.charAt(off + i));

    53         }

    54     }

    55 

    56     @Override

    57     public void write(char[] cbuf, int off, int len) throws IOException {

    58         for (int i = 0; i < len; i++) {

    59             write(cbuf[off + i]);

    60         }

    61     }

    62 

    63     @Override

    64     public void write(int c) throws IOException {

    65         if (lastChar == '\r' && c == '\n') {

    66             // Second character of CR+LF sequence.

    67             // Do nothing. We already started a new line on last character.

    68         } else {

    69             if (atBeginningOfLine) {

    70                 super.write(prefix, 0, prefix.length());

    71             }

    72             super.write(c);

    73             atBeginningOfLine = c == '\r' || c == '\n';

    74         }

    75         lastChar = (char) c;

    76     }

    77 }