SmartFileObject.java revision 2601:8e638f046bf0 
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 javax.lang.model.element.Modifier;
31import javax.lang.model.element.NestingKind;
32import javax.tools.JavaFileObject;
33
34import com.sun.tools.javac.util.DefinedBy;
35import com.sun.tools.javac.util.DefinedBy.Api;
36
37/**
38 * The SmartFileObject will return an outputstream that cache the written data
39 * and compare the new content with the old content on disk. Only if they differ,
40 * will the file be updated.
41 *
42 *  <p><b>This is NOT part of any supported API.
43 *  If you write code that depends on this, you do so at your own risk.
44 *  This code and its internal interfaces are subject to change or
45 *  deletion without notice.</b>
46 */
47public class SmartFileObject implements JavaFileObject {
48
49    JavaFileObject file;
50    PrintWriter stdout;
51
52    public SmartFileObject(JavaFileObject r, PrintWriter pw) {
53        file = r;
54        stdout = pw;
55    }
56
57    @Override
58    public boolean equals(Object other) {
59        return file.equals(other);
60    }
61
62    @Override
63    public int hashCode() {
64        return file.hashCode();
65    }
66
67    @DefinedBy(Api.COMPILER)
68    public Kind getKind() {
69        return file.getKind();
70    }
71
72    @DefinedBy(Api.COMPILER)
73    public boolean isNameCompatible(String simpleName, Kind kind) {
74        return file.isNameCompatible(simpleName, kind);
75    }
76
77    @DefinedBy(Api.COMPILER)
78    public URI toUri() {
79        return file.toUri();
80    }
81
82    @DefinedBy(Api.COMPILER)
83    public String getName() {
84        return file.getName();
85    }
86
87    @DefinedBy(Api.COMPILER)
88    public InputStream openInputStream() throws IOException {
89        return file.openInputStream();
90    }
91
92    @DefinedBy(Api.COMPILER)
93    public OutputStream openOutputStream() throws IOException {
94        return file.openOutputStream();
95    }
96
97    @DefinedBy(Api.COMPILER)
98    public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {
99        return file.getCharContent(ignoreEncodingErrors);
100    }
101
102    static String lineseparator = System.getProperty("line.separator");
103
104    @DefinedBy(Api.COMPILER)
105    public Writer openWriter() throws IOException {
106        StringBuilder s = new StringBuilder();
107        try (BufferedReader r = new BufferedReader(file.openReader(true))) {
108            while (r.ready()) {
109                s.append(r.readLine()+lineseparator);
110            }
111        } catch (FileNotFoundException e) {
112            // Perfectly ok.
113        }
114        return new SmartWriter(file, s.toString(), file.getName(), stdout);
115    }
116
117    @DefinedBy(Api.COMPILER)
118    public long getLastModified() {
119        return file.getLastModified();
120    }
121
122    @DefinedBy(Api.COMPILER)
123    public boolean delete() {
124        return file.delete();
125    }
126
127    @DefinedBy(Api.COMPILER)
128    public Modifier getAccessLevel() {
129        return file.getAccessLevel();
130    }
131
132    @DefinedBy(Api.COMPILER)
133    public NestingKind getNestingKind() {
134        return file.getNestingKind();
135    }
136
137    @DefinedBy(Api.COMPILER)
138    public Reader openReader(boolean ignoreEncodingErrors) throws IOException {
139        return file.openReader(ignoreEncodingErrors);
140    }
141
142}
143