arthas/arthas-tutorials-en/case/http-api/classpath-java-app.md

Get system properties of the Java application through Http api and extract the value of java.class.path{{}} .

json_data=$(curl -Ss -XPOST http://localhost:8563/api -d '{ "action":"exec", "command":"sysprop" }'){{execute T3}}

• Extract value with sed{{}} :

class_path=$(echo $json_data | tr -d '\n' | sed 's/.*"java.class.path":"\([^"]*\).*/\1/'); echo "classpath: $class_path"{{execute T3}}

• Extract value with json_pp/awk{{}} :

class_path=$(echo $json_data | tr -d '\n' | json_pp | grep java.class.path | awk -F'"' '{ print $4 }'); echo "classpath: $class_path"{{execute T3}}

Output:

classpath: math-game.jar

NOTE:

• echo $json_data | tr -d '\n'{{}} : Delete line breaks (the value of line.separator{{}} ) to avoid affecting the processing of sed{{}} /json_pp{{}} commands.
• awk -F'"' '{ print $4 }'{{}} : Use double quote as delimiter