mvn dependency tree filtered

mvnwhy.sh

# uses mvn dependency plugin to show why a certain dependency or dependencies are used

function mvnwhy() {
  CANDIDATES=(`mvn dependency:list | grep $1 | awk '{print $2}'`)

  for CANDIDATE in ${CANDIDATES[@]}; do
    echo "Why $CANDIDATE?"
    declare -a CANDIDATE_SEGMENTS
    CANDIDATE_SEGMENTS=(`echo $CANDIDATE | awk 'BEGIN{FS=":"}{for (i=1; i<=2; i++) print $i}'`)
    # this just works in zsh for bash use: DEPENDENCY=${CANDIDATE_SEGMENTS[0]}:${CANDIDATE_SEGMENTS[1]}
    DEPENDENCY=${CANDIDATE_SEGMENTS[1]}:${CANDIDATE_SEGMENTS[2]}
    # scans and shows dependency tree for every dep (this might get optimized later)
    # background: no way found to get always the right line before the pattern matches
    mvn dependency:tree -Dincludes=$DEPENDENCY | grep -B 1 "\\\-"
  done

}

mvnwhy_samples.sh

# single match 
mvnwhy com.jayway.jsonpath:json-path
# Output:
# Why com.jayway.jsonpath:json-path:jar:2.2.0:test?
# [INFO] com.meistermeier:rest-docs-sample:jar:0.0.1-SNAPSHOT
# [INFO] \- org.springframework.boot:spring-boot-starter-test:jar:1.4.1.RELEASE:test
# [INFO]    \- com.jayway.jsonpath:json-path:jar:2.2.0:test
#
#
# multi match
# call:
mvnwhy json
# Output:
# Why com.jayway.jsonpath:json-path:jar:2.2.0:test?
# [INFO] com.meistermeier:rest-docs-sample:jar:0.0.1-SNAPSHOT
# [INFO] \- org.springframework.boot:spring-boot-starter-test:jar:1.4.1.RELEASE:test
# [INFO]    \- com.jayway.jsonpath:json-path:jar:2.2.0:test
# Why org.json:json:jar:20140107:test?
# [INFO] com.meistermeier:rest-docs-sample:jar:0.0.1-SNAPSHOT
# [INFO] \- org.springframework.boot:spring-boot-starter-test:jar:1.4.1.RELEASE:test
# [INFO]    \- org.skyscreamer:jsonassert:jar:1.3.0:test
# [INFO]       \- org.json:json:jar:20140107:test
# Why net.minidev:json-smart:jar:2.2.1:test?
# [INFO] com.meistermeier:rest-docs-sample:jar:0.0.1-SNAPSHOT
# [INFO] \- org.springframework.boot:spring-boot-starter-test:jar:1.4.1.RELEASE:test
# [INFO]    \- com.jayway.jsonpath:json-path:jar:2.2.0:test
# [INFO]       \- net.minidev:json-smart:jar:2.2.1:test
# Why org.skyscreamer:jsonassert:jar:1.3.0:test?
# [INFO] com.meistermeier:rest-docs-sample:jar:0.0.1-SNAPSHOT
# [INFO] \- org.springframework.boot:spring-boot-starter-test:jar:1.4.1.RELEASE:test
# [INFO]    \- org.skyscreamer:jsonassert:jar:1.3.0:test

I don't have maven installed but the first awk may be replaced by cut -f2 (with the appropriate -d option) and the second awk could be replaced by cut -d: -f1-2, making the whole for-part just two lines:

[...]
    echo "Why $CANDIDATE?"
    mvn dependency:tree -Dincludes=$(echo $CANDIDATE | cut -d: -f1-2) | grep -B 1 "\\\-"
[...]