This module allows execution of Java compiled classes from the Kamailio config file, exporting functions to access the SIP message from Java using the Java Native Interface (JNI).

2. Dependencies

2.1. Kamailio Modules

The following modules must be loaded before this module:

none.

2.2. External Libraries or Applications

The following packages are runtime libraries, required to launch

java-common Base of all Java packages.
default-jre Standard Java or Java compatible Runtime.
gcj-jre Java runtime environment using GIJ/classpath.
libgcj12 (>=12) Java runtime library for use with gcj.

The following packages are optional, required for development

ant Java based build tool like make.
ant-contrib Collection of tasks, types and other tools for Apache Ant.
ant-gcj Java based build tool like make (GCJ).
default-jdk Standard Java or Java compatible Development Kit
gcj-jdk gcj and classpath development tools for Java(TM)
libgcj13-dev (>=12) Java development headers for use with gcj
jdk JDK Development Kit (either oracle jdk or openjdk)

The following libraries or applications must be compiled before running Kamailio with this module loaded:

The following packages are runtime libraries, required to launch

<class_name>.class
kamailio.jar

3. Java runtime

3.1. JRE or JDK is required to use this module

Java runtime library (JRE and JDK for building app_java) is required to use this module.

4. Parameters

4.1. `class_name` (string)

The class name should have the same compiled file name. If the value is "Kamailio", then the compiled file should be named as "Kamailio.class".

Default value is “Kamailio”.

Example 1.1. Set class_name parameter

...
modparam("app_java", "class_name", "Kamailio")
...

4.2. `child_init_method` (string)

TBD.

Default value is “child_init”.

Example 1.2. Set child_init_method parameter

...
modparam("app_java", "child_init_method", "my_mod_init")
...

4.3. `java_options` (string)

Java options for Java Virtual Machine. For more info read java docs

Default value is “-Djava.compiler=NONE”.

Example 1.3. Set java_options parameter

...
modparam("app_java", "java_options", "-Djava.compiler=NONE")
...

Example 1.4. Set java_options parameter (live configuration)

...
# Assumes "application java folder" is located at /opt/kamailio/java
modparam("app_java", "java_options", "-Djava.compiler=NONE
    -Djava.class.path=/path/to/kamailio/modules:/opt/kamailio/java:
    /opt/kamailio/java/kamailio.jar")
...

Example 1.5. Set java_options parameter (verbose configuration)

...
# Assumes "application java folder" is located at /opt/kamailio/java
modparam("app_java", "java_options", "-verbose:gc,class,jni
    -Djava.compiler=NONE -Djava.class.path=/path/to/kamailio/modules:
    /opt/kamailio/java:/opt/kamailio/java/kamailio.jar")
...

Example 1.6. Set java_options parameter (debug configuration)

...
# Assumes "application java folder" is located at /opt/kamailio/java
modparam("app_java", "java_options", "-Xdebug -verbose:gc,class,jni
    -Djava.compiler=NONE -Djava.class.path=/path/to/kamailio/modules:
    /opt/kamailio/java:/opt/kamailio/java/kamailio.jar")
...

4.4. `force_cmd_exec` (int)

This parameter forces execution a kamailio command with java native method “KamExec”. # Note: this is an untested yet feature, may cause (but may not) a memory leaks if used from embedded languages.

Default value is “0 (off)”.

Example 1.7. Set force_cmd_exec parameter

...
modparam("app_java", "force_cmd_exec", 1)
...

5. Functions

5.1. Common requirements

Each function has a required parameter “method_signature”. For more info see Determine the signature of a method. Signature represents the variable type. The mapping between the Java type and C type is

		Type     Chararacter
		boolean      Z
		byte         B
		char         C
		double       D
		float        F
		int          I
		long         J
		object       L
		short        S
		void         V
		Note that to specify an object, the "L" is followed by the
		object's class name and ends with a semi-colon, ';' .

app_java supports the following signatures:

		Primitives: Z,B,C,D,F,I,J,L,S,V
		Objects:
			Ljava/lang/Boolean;
			Ljava/lang/Byte;
			Ljava/lang/Character;
			Ljava/lang/Double;
			Ljava/lang/Float;
			Ljava/lang/Integer;
			Ljava/lang/Long;
			Ljava/lang/Short;
			Ljava/lang/String;
			NULL parameter: V

	Each parameter passed to function will be cast according to given signature.

	Parameters are optional, omitting a parameter meant the passed value is NULL.
	Parameters count should be exactly the same as signature count.
	Note 1: Arrays representation (symbol '[') is not supported yet.
	Note 2: You shall use a correct signature, e.g. the following examples
	of combinations are invalid:
    	java_method_exec("ExampleMethod", "ZI", "False");
        java_method_exec("ExampleMethod", "LI", "something", "5");

5.2. java_method_exec(method, method_signature, [param1[, param2[, ...]]])

Executes a java class method method. Parameter method_signature is required.

Example 1.8. Signature: "V"

Kamailio prototype

java_method_exec("ExampleMethod", "V");

Java prototype

public int ExampleMethod();

Example of usage:

# Kamailio
java_method_exec("ExampleMethod", "V");

# Java
public int ExampleMethod()
{
    ... do something;
    return 1;
}

Example 1.9. Signature: "Ljava/lang/String;I"

Kamailio prototype

java_method_exec("ExampleMethod", "Ljava/lang/String;I", "Hello world", "5");

Java prototype

public int ExampleMethod(String param1, int param2);

In the above scenario parameter 2 ("5") will be cast to integer representation.

Example of usage:

# Kamailio
java_method_exec("ExampleMethod", "Ljava/lang/String;I", "$mb", "$ml");

# Java
public int ExampleMethod(String SipMessageBuffer, int SipMessageLength)
{
    ... do something with buffer;
    return 1;
}

Example 1.10. Signature: "ZB"

Kamailio prototype

java_method_exec("ExampleMethod", "ZB", "true", "0x05");

Java prototype

public int ExampleMethod(boolean param1, byte param2);

In the above scenario parameter 1 ("true") will be cast to boolean representation.

Example of usage:

# Kamailio
java_method_exec("ExampleMethod", "ZB", "true", "0x05");

# Java
public int ExampleMethod(boolean flagSet, byte bFlag);
{
    if (flagSet)
    {
        ... do something with flags;
    }

    return 1;
}

5.3. java_staticmethod_exec(method, method_signature, [param1[, param2[, ...]]])

Executes a Java static method method. Parameter method_signature is required.

Example 1.11. Signature: "V"

Kamailio prototype

java_staticmethod_exec("ExampleMethod", "V");

Java prototype

public static int ExampleMethod();

Example of usage:

# Kamailio
java_staticmethod_exec("ExampleMethod", "V");

# Java
public static int ExampleMethod()
{
    ... do something;
    return 1;
}

Example 1.12. Signature: "Ljava/lang/String;I"

Kamailio prototype

java_staticmethod_exec("ExampleMethod", "Ljava/lang/String;I", "Hello world", "5");

Java prototype

public static int ExampleMethod(String param1, int param2);

In the above scenario parameter 2 ("5") will be cast to integer representation.

Example of usage:

# Kamailio
java_staticmethod_exec("ExampleMethod", "Ljava/lang/String;I", "$mb", "$ml");

# Java
public static int ExampleMethod(String SipMessageBuffer, int SipMessageLength)
{
    ... do something with buffer;
    return 1;
}

Example 1.13. Signature: "ZB"

Kamailio prototype

java_staticmethod_exec("ExampleMethod", "ZB", "true", "0x05");

Java prototype

public static int ExampleMethod(boolean param1, byte param2);

In the above scenario parameter 1 ("true") will be cast to boolean representation.

Example of usage:

# Kamailio
java_staticmethod_exec("ExampleMethod", "ZB", "true", "0x05");

# Java
public static int ExampleMethod(boolean flagSet, byte bFlag);
{
    if (flagSet)
    {
        ... do something with flags;
    }

    return 1;
}

5.4. java_s_method_exec(method, method_signature, [param1[, param2[, ...]]])

Executes a Java class synchronized method method. Parameter method_signature is required.

For more info see Synchronized Methods

Example 1.14. Signature: "V"

Kamailio prototype

java_s_method_exec("ExampleMethod", "V");

Java prototype

public synchronized int ExampleMethod();

Example of usage:

# Kamailio
java_s_method_exec("ExampleMethod", "V");

# Java
public synchronized int ExampleMethod()
{
    ... do something;
    return 1;
}

Example 1.15. Signature: "Ljava/lang/String;I"

Kamailio prototype

java_s_method_exec("ExampleMethod", "Ljava/lang/String;I", "Hello world", "5");

Java prototype

public synchronized int ExampleMethod(String param1, int param2);

In the above scenario parameter 2 ("5") will be cast to integer representation.

Example of usage:

# Kamailio
java_s_method_exec("ExampleMethod", "Ljava/lang/String;I", "$mb", "$ml");

# Java
public synchronized int ExampleMethod(String SipMessageBuffer, int SipMessageLength)
{
    ... do something with buffer;
    return 1;
}

Example 1.16. Signature: "ZB"

Kamailio prototype

java_s_method_exec("ExampleMethod", "ZB", "true", "0x05");

Java prototype

public synchronized int ExampleMethod(boolean param1, byte param2);

In the above scenario parameter 1 ("true") will be cast to boolean representation.

Example of usage:

# Kamailio
java_s_method_exec("ExampleMethod", "ZB", "true", "0x05");

# Java
public synchronized int ExampleMethod(boolean flagSet, byte bFlag);
{
    if (flagSet)
    {
        ... do something with flags;
    }

    return 1;
}

5.5. java_s_staticmethod_exec(method, method_signature, [param1[, param2[, ...]]])

Executes a java synchronized static method method. Parameter method_signature is required.

For more info see Synchronized Methods

Example 1.17. Signature: "V"

Kamailio prototype

java_s_staticmethod_exec("ExampleMethod", "V");

Java prototype

public static synchronized int ExampleMethod();

Example of usage:

# Kamailio
java_s_staticmethod_exec("ExampleMethod", "V");

# Java
public static synchronized int ExampleMethod()
{
    ... do something;
    return 1;
}

Example 1.18. Signature: "Ljava/lang/String;I"

Kamailio prototype

java_s_staticmethod_exec("ExampleMethod", "Ljava/lang/String;I", "Hello world", "5");

Java prototype

public static synchronized int ExampleMethod(String param1, int param2);

In the above scenario parameter 2 ("5") will be cast to integer representation.

Example of usage:

# Kamailio
java_s_staticmethod_exec("ExampleMethod", "Ljava/lang/String;I", "$mb", "$ml");

# Java
public static synchronized int ExampleMethod(String SipMessageBuffer, int SipMessageLength)
{
    ... do something with buffer;
    return 1;
}

Example 1.19. Signature: "ZB"

Kamailio prototype

java_s_staticmethod_exec("ExampleMethod", "ZB", "true", "0x05");

Java prototype

public static synchronized int ExampleMethod(boolean param1, byte param2);

In the above scenario parameter 1 ("true") will be cast to boolean representation.

Example of usage:

# Kamailio
java_s_staticmethod_exec("ExampleMethod", "ZB", "true", "0x05");

# Java
public static synchronized int ExampleMethod(boolean flagSet, byte bFlag);
{
    if (flagSet)
    {
        ... do something with flags;
    }

    return 1;
}

6. Java Module API

6.1. Minimal program skeleton

Example 1.20. Minimal program skeleton

import org.siprouter.*;
import org.siprouter.NativeInterface.*;

public class Kamailio extends NativeMethods
{
    /* Here you should specify a full path to app_java.so */
    static
    {
        System.load("/opt/kamailio/lib/kamailio/modules/app_java.so");
    }

    /* Constructor. Do not remove !!! */
    public Kamailio()
    {
    }

    /*
        This method should be executed for each children process, immediately after forking.
	Required. Do not remove !!!
    */
    public int child_init(int rank)
    {
	return 1;
    }
}

app_java Module

Konstantin Mosesov

Edited by

Konstantin Mosesov

Chapter 1. Admin Guide

1. Overview

2. Dependencies

2.1. Kamailio Modules

2.2. External Libraries or Applications

3. Java runtime

3.1. JRE or JDK is required to use this module

4. Parameters

4.1. class_name (string)

4.2. child_init_method (string)

4.3. java_options (string)

4.4. force_cmd_exec (int)

5. Functions

5.1. Common requirements

5.2. java_method_exec(method, method_signature, [param1[, param2[, ...]]])

5.3. java_staticmethod_exec(method, method_signature, [param1[, param2[, ...]]])

5.4. java_s_method_exec(method, method_signature, [param1[, param2[, ...]]])

5.5. java_s_staticmethod_exec(method, method_signature, [param1[, param2[, ...]]])

6. Java Module API

6.1. Minimal program skeleton

4.1. `class_name` (string)

4.2. `child_init_method` (string)

4.3. `java_options` (string)

4.4. `force_cmd_exec` (int)