How to Access a Maven Repository » History » Version 22
Henning Blohm, 31.07.2014 21:54
1 | 19 | Henning Blohm | h1. Maven Repos Support (MVNCR) |
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2 | 1 | Henning Blohm | |
3 | 19 | Henning Blohm | (#1696) |
4 | 1 | Henning Blohm | |
5 | 17 | Henning Blohm | Maven repository can be integrated with Z2 as component repositories. |
6 | 1 | Henning Blohm | |
7 | 20 | Henning Blohm | This is used for most of the [[Samples]] and [[Add-ons]] to access third-party binaries, so these are good examples. See [[Sample-hibernate-basic#How-this-sample-makes-use-of-MVNCR]] for a discussion on use of the MVNCR. |
8 | 18 | Henning Blohm | |
9 | For Add-ons it is typical to rely on fragments (see below) to declare dependencies, and for a sample (or - of course - any actual solution) it is typical to declare a maven component repository to set the actual remote source of artifacts (and more). |
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11 | 5 | Henning Blohm | h2. Principles |
12 | 1 | Henning Blohm | |
13 | 5 | Henning Blohm | The main idea is that based on some root artifacts and some maven remote repository configuration, jar artifacts and dependencies will be made available as Java component in Z2 that can be referenced or included as suits best. |
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15 | h2. Name mapping and version resolution |
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17 | 1 | Henning Blohm | Artefacts in Maven repos have a fully qualified name of the form |
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19 | <pre> |
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20 | <groupId>:<artifactId>:<version> |
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21 | </pre> |
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23 | 5 | Henning Blohm | or |
24 | 1 | Henning Blohm | |
25 | 5 | Henning Blohm | <pre> |
26 | <groupId>:<artifactId>:<packaging>:<version> |
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27 | </pre> |
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28 | 1 | Henning Blohm | |
29 | 5 | Henning Blohm | By default, a jar artifact @<groupId>:<artifactId>:<version>@ will result into a Java component of name |
30 | 1 | Henning Blohm | |
31 | <pre> |
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32 | 5 | Henning Blohm | <groupId>:<artifactId>/java |
33 | 1 | Henning Blohm | </pre> |
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35 | 5 | Henning Blohm | Given that the resolution of the root artifacts and dependencies lead to artifacts of the same packaging, group id, and artifact id but with different versions the higher version number will be used (but see #1695). |
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37 | 5 | Henning Blohm | h2. Example configuration |
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39 | A maven repository component may look like this: |
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41 | <pre> |
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42 | com.zfabrik.systemStates.participation=com.zfabrik.boot.main/sysrepo_up |
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43 | com.zfabrik.component.type=com.zfabrik.mvncr |
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44 | 9 | Henning Blohm | mvncr.priority=200 |
45 | mvncr.roots=\ |
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46 | org.springframework:spring-context:4.0.2.RELEASE,\ |
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47 | 5 | Henning Blohm | org.springframework:spring-aspects:4.0.2.RELEASE,\ |
48 | org.springframework:spring-tx:4.0.2.RELEASE,\ |
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49 | org.springframework:spring-orm:4.0.2.RELEASE,\ |
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50 | org.springframework:spring-web:4.0.2.RELEASE,\ |
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51 | org.springframework.security:spring-security-core:3.2.2.RELEASE,\ |
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52 | org.springframework.security:spring-security-web:3.2.2.RELEASE,\ |
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53 | org.springframework.security:spring-security-config:3.2.2.RELEASE,\ |
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54 | org.springframework.security:spring-security-aspects:3.2.2.RELEASE,\ |
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55 | 9 | Henning Blohm | org.hibernate:hibernate-entitymanager:4.3.4.Final,\ |
56 | 1 | Henning Blohm | aopalliance:aopalliance:1.0,\ |
57 | org.aspectj:aspectjweaver:1.7.4,\ |
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58 | org.aspectj:aspectjtools:1.6.9,\ |
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59 | 9 | Henning Blohm | |
60 | mvncr.excluded=\ |
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61 | org.jboss.spec.javax.transaction:jboss-transaction-api_1.2_spec |
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62 | |||
63 | mvncr.managed=\ |
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64 | commons-logging:commons-logging:1.1.2 |
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65 | 5 | Henning Blohm | </pre> |
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67 | By default, all non-optional compile scope dependencies will be resolved. The resulting Java component will have the target artifact as API library and all non-optional compile scope dependencies as public references in their mapped form. |
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69 | The z2 core will use lazy component class loaders to make sure that use of include libraries has virtually no runtime penalty. |
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71 | 13 | Henning Blohm | h2. Component properties |
72 | 6 | Henning Blohm | |
73 | 13 | Henning Blohm | |_. name |_. meaning |_. default | |
74 | | mvncr.settings | Specifies the location of the settings XML file relative to the components resources | settings.xml | |
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75 | | mvncr.roots | A comman-separated list of root artifacts. See below for more details | n.a. | |
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76 | | mvncr.priority | The repository priority in repository chaining as defined in IComponentsRepository | 500 | |
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77 | | mvncr.managed | Fixed artifact versions, if encountered during recursive root resolution. This corresponds to a <dependencyManagement> section in a Maven POM file | n.a. | |
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78 | | mvncr.excluded | A comma separated list of artifacts that will be skipped during resolution of any root | n.a. | |
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80 | 5 | Henning Blohm | h2. Fine-Tuning of the Dependency Graph |
81 | 9 | Henning Blohm | |
82 | 5 | Henning Blohm | In order to deviate from the default resolution and mapping, maven repository roots may be specified with a query string like this: |
83 | 1 | Henning Blohm | |
84 | <pre> |
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85 | 5 | Henning Blohm | org.springframework.security:spring-security-aspects:3.2.2.RELEASE?versioned=true&scope=RUNTIME&excluded=commons-logging:commons-logging:1.1.2 |
86 | 1 | Henning Blohm | </pre> |
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88 | 13 | Henning Blohm | Admissable query params are |
89 | 1 | Henning Blohm | |
90 | 13 | Henning Blohm | |_. param |_. meaning | |
91 | | versioned | If set to @true@, the version part will not be removed from the java component name mapping and instead a versioned name is used. That is, in the case above, a java component @org.springframework.security:spring-security-aspects:3.2.2.RELEASE/java@ would be mapped. This is useful if "non-default" versions are required. | |
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92 | | scope | Any of RUNTIME, COMPILE, PROVIDED, SYSTEM, TEST. Corresponds to the corresponding Maven dependency scopes. If set, non-optional dependencies of the respective scope will be traversed to resolve dependencies. | |
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93 | | excluded | Exclusions on the dependency graph. | |
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94 | 6 | Henning Blohm | |
95 | h2. Handling the impact of PROVIDED references |
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97 | At times, Maven provided artifacts require the presence of artifacts on the classpath that are expected to be required by the environment - most typically this is true for Web framework w.r.t the Servlet API. |
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98 | 8 | Henning Blohm | |
99 | 1 | Henning Blohm | In that case, it is simplest to create a Z2 project representation that includes all related artifacts (or include directly). In order to simplify this include process, includes may be specified to be transitively following Java component references by adding a corresponding query modifier to the include definition: |
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101 | <pre> |
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102 | java.publicIncludes=\ |
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103 | 6 | Henning Blohm | com.vaadin:vaadin-server?expand=true |
104 | 9 | Henning Blohm | </pre> |
105 | 12 | Henning Blohm | |
106 | 14 | Henning Blohm | h2. Modularising Maven Dependencies |
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108 | 21 | Henning Blohm | At times, it is useful to not have all required dependency roots in one component declaration but rather allow some modularization-friendly spread out declaration of dependency roots within a system. This is implemented by the *fragment* approach. |
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110 | For example, an addon may define additional references, but in order to be reusable, it should not dictate what source to resolve those dependencies from. For example, this "mvnFragment":https://redmine.z2-environment.net/projects/z2-addons/repository/revisions/master/entry/com.zfabrik.springframework/mvnFragment.properties is the fragment of the [[Spring Add-on]]: |
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112 | <pre> |
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113 | # |
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114 | # A fragment adding Maven dependencies |
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115 | # |
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116 | com.zfabrik.component.type=com.zfabrik.mvncr.fragment |
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118 | # |
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119 | # adds to default repository |
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120 | # |
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122 | mvncr.component=\ |
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123 | environment/mavenDefault |
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125 | mvncr.roots=\ |
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126 | org.springframework:spring-context-support:4.0.2.RELEASE,\ |
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127 | org.springframework:spring-context:4.0.2.RELEASE,\ |
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128 | org.springframework:spring-aspects:4.0.2.RELEASE,\ |
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129 | org.springframework:spring-tx:4.0.2.RELEASE,\ |
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130 | org.springframework:spring-orm:4.0.2.RELEASE,\ |
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131 | </pre> |
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133 | 22 | Henning Blohm | Fragments are useful beyond separation of dependency and source repository separation. As conflict resolution will always happen within the scope of *one* Maven component repository, merging roots from different fragments for one repository is more consistent (in terms of conflict resolution) than having different maven repository declaration. In fact, in most cases having one Maven Component Repository will be the only manageable approach. |
134 | 14 | Henning Blohm | |
135 | In order to add a _fragment_ to a Maven Component Repository declare a component of type *com.zfabrik.mvncr.fragment* with the following properties |
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137 | |_. name |_. meaning |_. default | |
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138 | 16 | Henning Blohm | | mvncr.component | The component name (or a comma-separated list of component names) of MVNCR declarations this fragment adds to or a fragment adding to some other mvncr | n.a. | |
139 | 14 | Henning Blohm | | mvncr.roots | As above. Will be merged with the repo this fragment adds to | n.a. | |
140 | | mvncr.managed | As above. Will be merged with the repo this fragment adds to | n.a. | |
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141 | | mvncr.excluded | As above. Will be merged with the repo this fragment adds to | n.a. | |
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144 | 12 | Henning Blohm | h2. Development Support |
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146 | When running in Development mode, the repository will also provide the source (classifier) artifact if available, so that the Eclipsoid plugins will provide source code attachments to the development environment whenever possible during classpath resolution. |
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147 | 9 | Henning Blohm | |
148 | h2. References |
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149 | 10 | Henning Blohm | |
150 | 7 | Henning Blohm | * Main Javadoc: "MvnRepositoryResource":http://www.z2-environment.net/javadoc/com.zfabrik.mvncr!2Fjava/impl/com/zfabrik/impl/mvncr/MvnRepositoryResource.html |
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152 | h2. To Dos |
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154 | 1 | Henning Blohm | # Handling of SNAPSHOT-Versions to be revisited |