| [[exec-component]] |
| = Exec Component |
| :page-source: components/camel-exec/src/main/docs/exec-component.adoc |
| |
| *Available as of Camel version 2.3* |
| |
| The Exec component can be used to execute system commands. |
| |
| == Dependencies |
| |
| Maven users need to add the following dependency to their `pom.xml` |
| |
| [source,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. |
| |
| == URI format |
| |
| [source,xml] |
| --------------------------- |
| 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 |
| |
| // component options: START |
| The Exec component supports 1 options, which are listed below. |
| |
| |
| |
| [width="100%",cols="2,5,^1,2",options="header"] |
| |=== |
| | Name | Description | Default | Type |
| | *basicPropertyBinding* (advanced) | Whether the component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities | false | boolean |
| |=== |
| // component options: END |
| |
| // endpoint options: START |
| The Exec endpoint is configured using URI syntax: |
| |
| ---- |
| exec:executable |
| ---- |
| |
| with the following path and query parameters: |
| |
| === Path Parameters (1 parameters): |
| |
| |
| [width="100%",cols="2,5,^1,2",options="header"] |
| |=== |
| | Name | Description | Default | Type |
| | *executable* | *Required* Sets the executable to be executed. The executable must not be empty or null. | | String |
| |=== |
| |
| |
| === Query Parameters (10 parameters): |
| |
| |
| [width="100%",cols="2,5,^1,2",options="header"] |
| |=== |
| | Name | Description | Default | Type |
| | *args* (producer) | The arguments may be one or many whitespace-separated tokens. | | String |
| | *binding* (producer) | A reference to a org.apache.commons.exec.ExecBinding in the Registry. | | ExecBinding |
| | *commandExecutor* (producer) | A reference to a org.apache.commons.exec.ExecCommandExecutor in the Registry that customizes the command execution. The default command executor utilizes the commons-exec library, which adds a shutdown hook for every executed command. | | ExecCommandExecutor |
| | *lazyStartProducer* (producer) | Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel's routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. | false | boolean |
| | *outFile* (producer) | The name of a file, created by the executable, that should be considered as its output. If no outFile is set, the standard output (stdout) of the executable will be used instead. | | String |
| | *timeout* (producer) | The timeout, in milliseconds, after which the executable should be terminated. If execution has not completed within the timeout, the component will send a termination request. | | long |
| | *useStderrOnEmptyStdout* (producer) | A boolean indicating that when stdout is empty, this component will populate the Camel Message Body with stderr. This behavior is disabled (false) by default. | false | boolean |
| | *workingDir* (producer) | The directory in which the command should be executed. If null, the working directory of the current process will be used. | | String |
| | *basicPropertyBinding* (advanced) | Whether the endpoint should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities | false | boolean |
| | *synchronous* (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean |
| |=== |
| // endpoint options: END |
| // spring-boot-auto-configure options: START |
| == Spring Boot Auto-Configuration |
| |
| When using Spring Boot make sure to use the following Maven dependency to have support for auto configuration: |
| |
| [source,xml] |
| ---- |
| <dependency> |
| <groupId>org.apache.camel</groupId> |
| <artifactId>camel-exec-starter</artifactId> |
| <version>x.x.x</version> |
| <!-- use the same version as your Camel core version --> |
| </dependency> |
| ---- |
| |
| |
| The component supports 2 options, which are listed below. |
| |
| |
| |
| [width="100%",cols="2,5,^1,2",options="header"] |
| |=== |
| | Name | Description | Default | Type |
| | *camel.component.exec.basic-property-binding* | Whether the component should use basic property binding (Camel 2.x) or the newer property binding with additional capabilities | false | Boolean |
| | *camel.component.exec.enabled* | Enable exec component | true | Boolean |
| |=== |
| // spring-boot-auto-configure options: END |
| |
| |
| == Message headers |
| |
| The supported headers are defined in |
| `org.apache.camel.component.exec.ExecBinding`. |
| |
| [width="100%",cols="10%,10%,10%,70%",options="header",] |
| |======================================================================= |
| |Name |Type |Message |Description |
| |
| |`ExecBinding.EXEC_COMMAND_EXECUTABLE` |`String` |`in` |The name of the system command that will be executed. Overrides |
| `executable` in the URI. |
| |
| |`ExecBinding.EXEC_COMMAND_ARGS` |`java.util.List<String>` |`in` |Command-line arguments to pass to the executed process. The arguments |
| are used literally - no quoting is applied. Overrides any existing |
| `args` in the URI. |
| |
| |`ExecBinding.EXEC_COMMAND_ARGS` |`String`| `in` |The arguments of the executable as a Single string where |
| each argument is whitespace separated (see `args` in URI option). The |
| arguments are used literally, no quoting is applied. Overrides any |
| existing `args` in the URI. |
| |
| |`ExecBinding.EXEC_COMMAND_OUT_FILE` |`String` |`in` |The name of a file, created by the executable, that should be considered |
| as its output. Overrides any existing `outFile` in the URI. |
| |
| |`ExecBinding.EXEC_COMMAND_TIMEOUT` |`long` |`in` |The timeout, in milliseconds, after which the executable should be |
| terminated. Overrides any existing `timeout` in the URI. |
| |
| |`ExecBinding.EXEC_COMMAND_WORKING_DIR` |`String` |`in` |The directory in which the command should be executed. Overrides any |
| existing `workingDir` in the URI. |
| |
| |`ExecBinding.EXEC_EXIT_VALUE` |`int` |`out` |The value of this header is the _exit value_ of the executable. Non-zero |
| exit values typically indicate abnormal termination. Note that the exit |
| value is OS-dependent. |
| |
| |`ExecBinding.EXEC_STDERR` |`java.io.InputStream` |`out` |The value of this header points to the standard error stream (stderr) of |
| the executable. If no stderr is written, the value is `null`. |
| |
| |`ExecBinding.EXEC_USE_STDERR_ON_EMPTY_STDOUT` |`boolean` |`in` |Indicates that when `stdout` is empty, this component will populate the |
| Camel Message Body with `stderr`. This behavior is disabled (`false`) by |
| default. |
| |======================================================================= |
| |
| == Message body |
| |
| If the `Exec` component receives an `in` message body that is |
| convertible to `java.io.InputStream`, it is used to feed input to the |
| executable via its stdin. After execution, |
| http://camel.apache.org/exchange.html[the message body] is the result of |
| the execution,- that is, an |
| `org.apache.camel.components.exec.ExecResult` instance containing the |
| stdout, stderr, exit value, and out file. This component supports the |
| following `ExecResult` http://camel.apache.org/type-converter.html[type |
| converters] for convenience: |
| |
| [width="100%",cols="50%,50%",options="header",] |
| |======================================================================= |
| |From |To |
| |
| |`ExecResult` |`java.io.InputStream` |
| |
| |`ExecResult` |`String` |
| |
| |`ExecResult` |`byte []` |
| |
| |`ExecResult` |`org.w3c.dom.Document` |
| |======================================================================= |
| |
| If an out file is specified (in the endpoint via `outFile` or the |
| message headers via `ExecBinding.EXEC_COMMAND_OUT_FILE`), converters |
| will return the content of the out file. If no out file is used, then |
| this component will convert the stdout of the process to the target |
| type. For more details, please refer to the xref:exec-component.adoc[usage examples] below. |
| |
| == 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 to |
| the standard output stream of `wc`. |
| |
| [source,java] |
| -------------------------------------------------------------------------------------- |
| 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. |
| |
| [source,java] |
| -------------------------------------- |
| 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`. |
| |
| [source,java] |
| ---------------------------------------------------------------------------------------------------- |
| 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 http://ant.apache.org/[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. |
| |
| [source,java] |
| -------------------------------------------------- |
| from("direct:exec") |
| .to("exec:ant.bat?args=-f CamelExecBuildFile.xml") |
| -------------------------------------------------- |
| |
| In the next example, the `ant.bat` command redirects its output to |
| `CamelExecOutFile.txt` with `-l`. The file `CamelExecOutFile.txt` is |
| used as the 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. |
| |
| [source,java] |
| ------------------------------------------------------------------------------------------------------- |
| 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 |
| } |
| }); |
| ------------------------------------------------------------------------------------------------------- |
| |
| === Executing `echo` (Windows) |
| |
| Commands such as `echo` and `dir` can be executed only with the command |
| interpreter of the operating system. This example shows how to execute |
| such a command - `echo` - in Windows. |
| |
| [source,java] |
| ---------------------------------------------------------- |
| from("direct:exec").to("exec:cmd?args=/C echo echoString") |
| ---------------------------------------------------------- |
| |