Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
ClassLoaderUtils |
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1.5;1.5 |
1 | /* |
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2 | * Copyright 2012-2013 smartics, Kronseder & Reiner GmbH |
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3 | * |
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4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
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5 | * you may not use this file except in compliance with the License. |
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6 | * You may obtain a copy of the License at |
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7 | * |
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8 | * http://www.apache.org/licenses/LICENSE-2.0 |
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9 | * |
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10 | * Unless required by applicable law or agreed to in writing, software |
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11 | * distributed under the License is distributed on an "AS IS" BASIS, |
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12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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13 | * See the License for the specific language governing permissions and |
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14 | * limitations under the License. |
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15 | */ |
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16 | package de.smartics.properties.spi.core.util; |
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17 | ||
18 | import java.net.URL; |
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19 | ||
20 | import de.smartics.util.lang.classpath.ClassPathContext; |
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21 | ||
22 | /** |
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23 | * Utilities dealing with class loaders. |
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24 | */ |
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25 | public final class ClassLoaderUtils |
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26 | { |
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27 | // ********************************* Fields ********************************* |
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28 | ||
29 | // --- constants ------------------------------------------------------------ |
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30 | ||
31 | // --- members -------------------------------------------------------------- |
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32 | ||
33 | // ****************************** Initializer ******************************* |
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34 | ||
35 | // ****************************** Constructors ****************************** |
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36 | ||
37 | private ClassLoaderUtils() |
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38 | 0 | { |
39 | 0 | } |
40 | ||
41 | // ****************************** Inner Classes ***************************** |
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42 | ||
43 | // ********************************* Methods ******************************** |
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44 | ||
45 | // --- init ----------------------------------------------------------------- |
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46 | ||
47 | // --- get&set -------------------------------------------------------------- |
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48 | ||
49 | // --- business ------------------------------------------------------------- |
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50 | ||
51 | /** |
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52 | * Determines the path to the class loader root that contains the given |
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53 | * {@code type}. |
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54 | * |
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55 | * @param type the type whose class loader root is requested. |
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56 | * @return the class loader root. |
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57 | * @throws NullPointerException if {@code type} is <code>null</code>. |
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58 | */ |
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59 | public static String calcArchivePath(final Class<?> type) |
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60 | throws NullPointerException |
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61 | { |
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62 | 0 | final ClassLoader loader = type.getClassLoader(); |
63 | 0 | final String resource = type.getName().replace('.', '/') + ".class"; |
64 | 0 | final String path = calcFirstArchivePath(loader, resource); |
65 | 0 | return path; |
66 | } |
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67 | ||
68 | /** |
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69 | * Determines the path to the class loader root that contains the given |
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70 | * {@code resource}. The first matching path is returned. This call does not |
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71 | * check if there is more than one path that serves the given {@code resource} |
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72 | * . |
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73 | * |
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74 | * @param loader the loader to load the resource. |
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75 | * @param resource the resource whose class loader root is requested. |
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76 | * @return the class loader root for the given {@code resource}. |
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77 | * @throws NullPointerException if {@code loader} or {@code resource} is |
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78 | * <code>null</code>. |
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79 | * @throws IllegalArgumentException if the resource cannot be found by the |
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80 | * given class loader. |
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81 | */ |
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82 | public static String calcFirstArchivePath(final ClassLoader loader, |
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83 | final String resource) throws NullPointerException, |
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84 | IllegalArgumentException |
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85 | { |
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86 | 0 | final URL url = loader.getResource(resource); |
87 | 0 | if (url == null) |
88 | { |
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89 | 0 | throw new IllegalArgumentException( |
90 | "The resource '" + resource |
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91 | + "' cannot be found by the given class loader."); |
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92 | } |
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93 | 0 | final String urlString = url.toExternalForm(); |
94 | 0 | final int endIndex = urlString.length() - resource.length(); |
95 | 0 | final String path = urlString.substring(0, endIndex); |
96 | 0 | return path; |
97 | } |
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98 | ||
99 | /** |
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100 | * Creates the class path context for the given class loader and its derived |
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101 | * context root. The first matching path is used to calculate the class path |
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102 | * root. This call does not check if there is more than one path that serves |
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103 | * the given {@code resource}. |
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104 | * |
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105 | * @param classLoader the class loader to access resources. |
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106 | * @param resource the resource whose class loader root is requested. |
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107 | * @return the class path context. |
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108 | */ |
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109 | public static ClassPathContext createClassPathContext( |
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110 | final ClassLoader classLoader, final String resource) |
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111 | { |
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112 | 0 | final String root = calcFirstArchivePath(classLoader, resource); |
113 | 0 | return new ClassPathContext(classLoader, root); |
114 | } |
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115 | ||
116 | // --- object basics -------------------------------------------------------- |
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117 | ||
118 | } |