JShellToolProvider.java revision 3843:e5a42ddaf633 
1/*
2 * Copyright (c) 2016, 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 jdk.internal.jshell.tool;
27
28import java.io.InputStream;
29import java.io.OutputStream;
30import java.io.PrintStream;
31import java.util.Collections;
32import java.util.EnumSet;
33import java.util.Set;
34import javax.lang.model.SourceVersion;
35import javax.tools.Tool;
36import jdk.jshell.tool.JavaShellToolBuilder;
37
38/**
39 * Provider for launching the jshell tool.
40 */
41public class JShellToolProvider implements Tool {
42
43    /**
44     * Returns the name of this Java shell tool provider.
45     *
46     * @return the name of this tool provider
47     */
48    @Override
49    public String name() {
50        return "jshell";
51    }
52
53    /**
54     * Run the jshell tool.  The streams {@code out} and {@code err} are
55     * converted to {@code PrintStream} if they are not already.
56     * Any {@code Exception} is caught, printed and results in a non-zero return.
57     *
58     * @param in command line input (snippets and commands), and execution
59     * "standard" input; use System.in if null
60     * @param out command line output, feedback including errors, and execution
61     * "standard" output; use System.out if null
62     * @param err start-up errors and execution "standard" error; use System.err
63     * if null
64     * @param arguments arguments to pass to the tool
65     * @return 0 for success; nonzero otherwise
66     * @throws NullPointerException if the array of arguments contains
67     * any {@code null} elements.
68     */
69    @Override
70    public int run(InputStream in, OutputStream out, OutputStream err, String... arguments) {
71        InputStream xin =
72                (in == null)
73                        ? System.in
74                        : in;
75        PrintStream xout =
76                (out == null)
77                        ? System.out
78                        : (out instanceof PrintStream)
79                                ? (PrintStream) out
80                                : new PrintStream(out);
81        PrintStream xerr =
82                (err == null)
83                        ? System.err
84                        : (err instanceof PrintStream)
85                                ? (PrintStream) err
86                                : new PrintStream(err);
87        try {
88            JavaShellToolBuilder
89                    .builder()
90                    .in(xin, null)
91                    .out(xout)
92                    .err(xerr)
93                    .run(arguments);
94            return 0;
95        } catch (Throwable ex) {
96            xerr.println(ex.getMessage());
97            return 1;
98        }
99    }
100
101    /**
102     * Returns the source versions of the jshell tool.
103     * @return a set of supported source versions
104     */
105    @Override
106    public Set<SourceVersion> getSourceVersions() {
107        return Collections.unmodifiableSet(
108                EnumSet.range(SourceVersion.RELEASE_9, SourceVersion.latest()));
109    }
110
111    /**
112     * Launch the tool.
113     * @param arguments the command-line arguments (including options), if any
114     * @throws Exception an unexpected fatal exception
115     */
116    public static void main(String[] arguments) throws Exception {
117        JavaShellToolBuilder
118                .builder()
119                .run(arguments);
120    }
121}
122