SmartFileObject.java revision 2674:e284f560acf6 
1/*
2 * Copyright (c) 2012, 2014, 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
26package com.sun.tools.sjavac.comp;
27
28import java.io.*;
29import java.net.URI;
30import java.nio.file.NoSuchFileException;
31
32import javax.lang.model.element.Modifier;
33import javax.lang.model.element.NestingKind;
34import javax.tools.JavaFileObject;
35
36import com.sun.tools.javac.util.DefinedBy;
37import com.sun.tools.javac.util.DefinedBy.Api;
38
39/**
40 * The SmartFileObject will return an outputstream that cache the written data
41 * and compare the new content with the old content on disk. Only if they differ,
42 * will the file be updated.
43 *
44 *  <p><b>This is NOT part of any supported API.
45 *  If you write code that depends on this, you do so at your own risk.
46 *  This code and its internal interfaces are subject to change or
47 *  deletion without notice.</b>
48 */
49public class SmartFileObject implements JavaFileObject {
50
51    JavaFileObject file;
52    PrintWriter stdout;
53
54    public SmartFileObject(JavaFileObject r, PrintWriter pw) {
55        file = r;
56        stdout = pw;
57    }
58
59    @Override
60    public boolean equals(Object other) {
61        return file.equals(other);
62    }
63
64    @Override
65    public int hashCode() {
66        return file.hashCode();
67    }
68
69    @DefinedBy(Api.COMPILER)
70    public Kind getKind() {
71        return file.getKind();
72    }
73
74    @DefinedBy(Api.COMPILER)
75    public boolean isNameCompatible(String simpleName, Kind kind) {
76        return file.isNameCompatible(simpleName, kind);
77    }
78
79    @DefinedBy(Api.COMPILER)
80    public URI toUri() {
81        return file.toUri();
82    }
83
84    @DefinedBy(Api.COMPILER)
85    public String getName() {
86        return file.getName();
87    }
88
89    @DefinedBy(Api.COMPILER)
90    public InputStream openInputStream() throws IOException {
91        return file.openInputStream();
92    }
93
94    @DefinedBy(Api.COMPILER)
95    public OutputStream openOutputStream() throws IOException {
96        return file.openOutputStream();
97    }
98
99    @DefinedBy(Api.COMPILER)
100    public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {
101        return file.getCharContent(ignoreEncodingErrors);
102    }
103
104    static String lineseparator = System.getProperty("line.separator");
105
106    @DefinedBy(Api.COMPILER)
107    public Writer openWriter() throws IOException {
108        StringBuilder s = new StringBuilder();
109        try (BufferedReader r = new BufferedReader(file.openReader(true))) {
110            while (r.ready()) {
111                s.append(r.readLine()+lineseparator);
112            }
113        } catch (FileNotFoundException | NoSuchFileException e) {
114            // Perfectly ok.
115        }
116        return new SmartWriter(file, s.toString(), file.getName(), stdout);
117    }
118
119    @DefinedBy(Api.COMPILER)
120    public long getLastModified() {
121        return file.getLastModified();
122    }
123
124    @DefinedBy(Api.COMPILER)
125    public boolean delete() {
126        return file.delete();
127    }
128
129    @DefinedBy(Api.COMPILER)
130    public Modifier getAccessLevel() {
131        return file.getAccessLevel();
132    }
133
134    @DefinedBy(Api.COMPILER)
135    public NestingKind getNestingKind() {
136        return file.getNestingKind();
137    }
138
139    @DefinedBy(Api.COMPILER)
140    public Reader openReader(boolean ignoreEncodingErrors) throws IOException {
141        return file.openReader(ignoreEncodingErrors);
142    }
143
144}
145