Spring Boot AngularJs Application: angular-bootstrap.css generation using wro4j-maven-plugin Fails

Question

I am following the part 1 of this tutorial . I have reached this section " Loading a Dynamic Resource from Angular ". As per the tutorial instructions, when I build the aplication using maven mvn clean package , the wro4j-maven-plugin fails to generate the angular-bootstrap.css but the angular-bootstrap.js is generated successfully. I am getting the following warnings in the mvn console

$ mvn clean package
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building demo 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.6.1:clean (default-clean) @ myDemo ---
[INFO] Deleting E:\workspace\demo\target
[INFO]
[INFO] --- wro4j-maven-plugin:1.8.0:run (default) @ myDemo ---
[INFO] E:\workspace\demo/src/main/wro
[INFO] Executing the mojo:
[INFO] Wro4j Model path: E:\workspace\demo\src\main\wro\wro.xml
[INFO] targetGroups: null
[INFO] minimize: true
[INFO] ignoreMissingResources: null
[INFO] parallelProcessing: false
[INFO] buildDirectory: E:\workspace\demo\target
[INFO] destinationFolder: E:\workspace\demo\target
[INFO] jsDestinationFolder: E:\workspace\demo\target\classes\static\js
[INFO] cssDestinationFolder: E:\workspace\demo\target\classes\static\css
[INFO] The following groups will be processed: [angular-bootstrap]
[INFO] folder: E:\workspace\demo\target\classes\static\css
[INFO] processing group: angular-bootstrap.css
[WARNING] Less warnings are:
[WARNING] 0:2 Cannot link source map. Css result location is not know and could not be deduced from input less source..
[INFO] folder: E:\workspace\demo\target\classes\static\js
[INFO] processing group: angular-bootstrap.js
[INFO] file size: angular-bootstrap.js -> 240652 bytes
[INFO] E:\workspace\demo\target\classes\static\js\angular-bootstrap.js (240652 bytes)

As a result of this, when I run the application, I am getting 404 for angular-bootstrap.css. Please let me know where I am going wrong. Please find the relevant configurations below.

/demo/src/main/wro/wro.xml

<groups xmlns="http://www.isdc.ro/wro">
  <group name="angular-bootstrap">
    <css>webjar:bootstrap/3.3.7-1/less/bootstrap.less</css>   
    <css>file:@project.basedir@/src/main/wro/main.less</css>
    <js>webjar:jquery/2.2.4/jquery.min.js</js>
    <js>webjar:angularjs/1.4.9/angular.min.js</js>
    <js>webjar:angularjs/1.4.9/angular-route.min.js</js>
    <js>webjar:angularjs/1.4.9/angular-cookies.min.js</js>
   </group>
</groups>

/demo/src/main/wro/wro.properties

preProcessors=lessCssImport
postProcessors=less4j,jsMin

/demo/src/main/wro/main.less [Actually this file is empty.]

/demo/pom.xml

<build>

  <plugins>
    <plugin>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-maven-plugin</artifactId>
    </plugin>
    <plugin>
      <groupId>ro.isdc.wro4j</groupId>
      <artifactId>wro4j-maven-plugin</artifactId>
      <version>1.8.0</version>
      <executions>
        <execution>
          <phase>generate-resources</phase>
          <goals>
            <goal>run</goal>
          </goals>
        </execution>
      </executions>
      <configuration>
        <wroManagerFactory>ro.isdc.wro.maven.plugin.manager.factory.ConfigurableWroManagerFactory</wroManagerFactory>
        <cssDestinationFolder>${project.build.directory}/classes/static/css</cssDestinationFolder>
        <jsDestinationFolder>${project.build.directory}/classes/static/js</jsDestinationFolder>
        <wroFile>${basedir}/src/main/wro/wro.xml</wroFile>
        <extraConfigFile>${basedir}/src/main/wro/wro.properties</extraConfigFile>
        <contextFolder>${basedir}/src/main/wro</contextFolder>
      </configuration>
      <dependencies>
        <dependency>
          <groupId>org.webjars</groupId>
          <artifactId>jquery</artifactId>
          <version>2.2.4</version>
        </dependency>
        <dependency>
          <groupId>org.webjars</groupId>
          <artifactId>angularjs</artifactId>
          <version>1.4.9</version>
        </dependency>
        <dependency>
          <groupId>org.webjars</groupId>
          <artifactId>bootstrap</artifactId>
          <version>3.3.7</version>
        </dependency>
      </dependencies>
    </plugin>
  </plugins>

</build>

I am using

Apache Maven 3.3.9
Java version: 1.8.0_111
spring-boot 1.4.2.RELEASE
OS : windows 10

Edit 1

I tried with --debug flag in mvn. I got this debug message

[DEBUG] Created file: angular-bootstrap.css
[DEBUG] No content found for group: angular-bootstrap.css

Answer 1

The issue got fixed after changing the version of bootstrap in pom.xml as follows

<dependency>
  <groupId>org.webjars</groupId>
  <artifactId>bootstrap</artifactId>
  <version>3.3.7-1</version>
</dependency>

Now the angular-bootstrap.css is getting generated successfully.

Answer 2

在本教程之后，我遇到了同样的问题，并通过复制pom.xml的wro4j <plugin>...</plugin>块和演示页面上链接的github项目中的wro.xml文件内容来wro.xml了它而不是使用该页面上的代码示例。

Answer 3

Actually, you can find an updated version on the github repositry published along with the solution (I also published a pull request for that matter).

Problem is, I find it breaks the DRY principle, as they repeat jquery, bootstrap and angularjs versions.

Three steps to correct the problem:

1. Defining versions in one place (Maven properties element):

    <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <wro4j.version>1.8.0</wro4j.version> <bootstrap.version>3.3.7-1</bootstrap.version> <angularjs.version>1.5.9</angularjs.version> <jquery.version>3.1.1-1</jquery.version> </properties> 

2. Reusing the generated-resources folders to allow IntelliJ and other IDEs to resolve the path for the generated files, in the plugin configuration:

    <build> <resources> <resource> <directory>${project.basedir}/src/main/resources</directory> </resource> <resource> <directory>${project.build.directory}/generated-resources</directory> </resource> </resources> <plugins> <plugin> <artifactId>maven-resources-plugin</artifactId> <executions> <execution> <!-- Serves *only* to filter the wro.xml so it can get an absolute path for the project --> <id>copy-resources</id> <phase>validate</phase> <goals> <goal>copy-resources</goal> </goals> <configuration> <outputDirectory>${basedir}/target/wro</outputDirectory> <resources> <resource> <directory>src/main/wro</directory> <filtering>true</filtering> </resource> </resources> </configuration> </execution> </executions> </plugin> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> <plugin> <groupId>ro.isdc.wro4j</groupId> <artifactId>wro4j-maven-plugin</artifactId> <version>${wro4j.version}</version> <executions> <execution> <phase>compile</phase> <goals> <goal>run</goal> </goals> </execution> </executions> <configuration> <wroManagerFactory>ro.isdc.wro.maven.plugin.manager.factory.ConfigurableWroManagerFactory </wroManagerFactory> <cssDestinationFolder>${project.build.directory}/generated-resources/static/css </cssDestinationFolder> <jsDestinationFolder>${project.build.directory}/generated-resources/static/js</jsDestinationFolder> <wroFile>${project.build.directory}/wro/wro.xml</wroFile> <extraConfigFile>${project.build.directory}/wro/wro.properties</extraConfigFile> <contextFolder>${project.build.directory}/wro</contextFolder> </configuration> <dependencies> <dependency> <groupId>org.webjars</groupId> <artifactId>jquery</artifactId> <version>${jquery.version}</version> </dependency> <dependency> <groupId>org.webjars</groupId> <artifactId>angularjs</artifactId> <version>${angularjs.version}</version> </dependency> <dependency> <groupId>org.webjars</groupId> <artifactId>bootstrap</artifactId> <version>${bootstrap.version}</version> </dependency> </dependencies> </plugin> </plugins> </build> 

3. Take advantage of Spring properties filtering in wro.xml:

    <groups xmlns="http://www.isdc.ro/wro"> <group name="angular-bootstrap"> <css>webjar:bootstrap/@bootstrap.version@/less/bootstrap.less</css> <css>file:src/main/wro/main.less</css> <js>webjar:jquery/@jquery.version@/jquery.min.js</js> <js>webjar:angularjs/@angularjs.version@/angular.min.js</js> <js>webjar:angularjs/@angularjs.version@/angular-route.min.js</js> <js>webjar:angularjs/@angularjs.version@/angular-cookies.min.js</js> </group> </groups>