Exec component
Available in Camel 2.3
The exec
component can be used to execute a system command.
Dependencies
Maven users need to add the following dependency to their pom.xml
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-exec</artifactId> <version>${camel-version}</version> </dependency>
where ${camel-version
} must be replaced by the actual version of Camel (2.3.0 or higher).
URI format
exec://executable[?options]
where executable
is the name, or file path, of the system command that will be executed. If executable name is used (e.g. exec:java
), the executable must in the system path.
URI options
Name |
Default value |
Description |
---|---|---|
|
|
The arguments of the executable. The arguments may be one or many |
|
|
The directory in which the command should be executed. If |
|
|
The timeout, in milliseconds, after which the executable should be terminated. If the executable has has not finished within the timeout, the component will send a termination request. |
|
|
The name of a file, created by the executable, that should be considered as output of the executable. If no |
|
a |
A reference to a |
|
a |
A reference to a |
Message headers
The supported headers are defined in org.apache.camel.component.exec.ExecBinding
.
Name |
Type |
Message |
Description |
---|---|---|---|
|
|
|
The name of the system command that will be executed. Overrides the |
|
|
|
The arguments of the executable. The arguments are used literally, no quoting is applied. Overrides existing |
|
|
|
The name of a file, created by the executable, that should be considered as output of the executable. Overrides existing |
|
|
|
The timeout, in milliseconds, after which the executable should be terminated. Overrides existing |
|
|
|
The directory in which the command should be executed. Overrides existing |
|
|
|
The value of this header is the exit value of the executable. Typically not-zero exit values indicates abnormal termination. Note that the exit value is OS-dependent. |
|
|
|
The value of this header points to the standard error stream (stderr) of the executable. If no stderr is written, the value is |
Message body
If the in
message body, that that the Exec
component receives, is convertible to java.io.InputStream
, it is used to feed input of the executable via its stdin. After the execution, the message body is the result of the execution, that is org.apache.camel.components.exec.ExecResult
instance containing the stdout, stderr, exit value and out file. The component supports the following ExecResult
type converters for convenience:
From |
To |
---|---|
|
|
|
|
|
|
|
|
If out file is used (the endpoint is configured with outFile
, or there is ExecBinding.EXEC_COMMAND_OUT_FILE
header) the converters return the content of the out file. If no out file is used, then the converters will use the stdout of the process for conversion to the target type. For example refer to the usage examples.
Usage examples
Executing word count (Linux)
The example below executes wc
(word count, Linux) to count the words in file /usr/share/dict/words
. The word count (output) is written in the standart output stream of wc
.
from("direct:exec") .to("exec:wc?args=--words /usr/share/dict/words") .process(new Processor() { public void process(Exchange exchange) throws Exception { // By default, the body is ExecResult instance assertIsInstanceOf(ExecResult.class, exchange.getIn().getBody()); // Use the Camel Exec String type converter to convert the ExecResult to String // In this case, the stdout is considered as output String wordCountOutput = exchange.getIn().getBody(String.class); // do something with the word count } });
Executing java
The example below executes java
with 2 arguments: -server
and -version
, provided that java
is in the system path.
from("direct:exec") .to("exec:java?args=-server -version")
The example below executes java
in c:/temp
with 3 arguments: -server
, -version
and the sytem property user.name
.
from("direct:exec") .to("exec:c:/program files/jdk/bin/java?args=-server -version -Duser.name=Camel&workingDir=c:/temp")
Executing Ant scripts
The following example executes Apache Ant (Windows only) with the build file CamelExecBuildFile.xml
, provided that ant.bat
is in the system path, and that CamelExecBuildFile.xml
is in the current directory.
from("direct:exec") .to(exec:ant.bat?args=-f CamelExecBuildFile.xml")
In the next example, the ant.bat
command, redirects the ant output to CamelExecOutFile.txt
with -l
. The file CamelExecOutFile.txt
is used as out file with outFile=CamelExecOutFile.txt
. The example assumes that ant.bat
is in the system path, and that CamelExecBuildFile.xml
is in the current directory.
from("direct:exec") .to("exec:ant.bat?args=-f CamelExecBuildFile.xml -l CamelExecOutFile.txt&outFile=CamelExecOutFile.txt") .process(new Processor() { public void process(Exchange exchange) throws Exception { InputStream outFile = exchange.getIn().getBody(InputStream.class); assertIsInstanceOf(InputStream.class, outFile); // do something with the out file here } });