Make the agent configurable via configuration file

Related to #34

Signed-off-by: Jakub Filak <jfilak@redhat.com>

README

@@ -16,10 +16,20 @@ It needs to be compiled as a shared native library (.so) and then loaded into
 JVM using -agentlib command line parameter.
 
 
+Configuration
+-------------
+
+The agent can be configured either via configuration file or via command line
+arguments. The command line arguments have higher priority and overwrites
+values loaded from the configuration file.
+
+The default path to the configuration file is '/etc/abrt/plugins/java.conf'.
+
+
 Examples
 --------
 
-Before you can run the example, you need to make sure that
+Before you can run the examples, you need to make sure that
 libabrt-java-connector.so is placed somewhere in the ld searched directories
 or configure LD_LIBRARY_PATH environment variable to point to a directory
 containing the library.
@@ -76,7 +86,7 @@ $  java -agentlib:abrt-java-connector=journald=off $MyClass -platform.jvmtiSuppo
 $  java -agentlib:abrt-java-connector=syslog=on $MyClass -platform.jvmtiSupported true
 
 Example5:
-- this example shows how configure abrt-java-connector to fill 'executable'
+- this example shows how to configure abrt-java-connector to fill 'executable'
   ABRT file with a path to a class on the bottom of the stack trace (the first
   method of thread)
 - this feature can be enabled via 'executable' option which can contain either
@@ -86,3 +96,23 @@ $  java -agentlib:abrt-java-connector=executable=threadclass $MyClass -platform.
 
 - 'mainclass' is used when 'executable' option is not passed and 'executable'
   file is filled with full path $MyClass
+
+
+Example6:
+- this example shows how to enrich the exception report with extra debug information
+- abrt-java-connector is capable to call a static method returning String at
+  time of processing exception
+- while creating the exception report methods from the list stored in
+  'debugmethod' option are called, not all of them, but only those whose defining
+  class was already loaded by 'System Class Loader'
+
+$  java -agentlib:abrt-java-connector=debugmethod=com.example.$MyClass.getMethod $MyClass
+
+
+Example7:
+- this example shows how to change the path to configuration file
+- the default configuration file path is '/etc/abrt/plugins/java.conf'
+- empty 'conffile' option means do not read any configuration file
+
+
+$  java -agentlib:abrt-java-connector=conffile=/etc/foo/example.conf $MyClass

etc/CMakeLists.txt

@@ -6,3 +6,9 @@ install(FILES java_event.conf.5 bugzilla_format_java.conf.5 bugzilla_formatdup_j
 
 install(FILES bugzilla_format_java.conf bugzilla_formatdup_java.conf
         DESTINATION ${SYSCONF_INSTALL_DIR}/libreport/plugins)
+
+install(FILES java.conf
+        DESTINATION ${SYSCONF_INSTALL_DIR}/abrt/plugins)
+
+install(FILES java.conf
+        DESTINATION ${SHARE_INSTALL_PREFIX}/abrt/conf.d/plugins)

etc/java.conf

@@ -0,0 +1,36 @@
+# Which frame of a stack trace to use for 'executable'
+# Allowed options are 'mainclass' or 'threadclass' where
+# 'mainclass' is used when this option is not configured.
+# executable = threadclass
+
+# Enables reporting of exceptions to ABRT
+# Default value: off
+abrt = on
+
+# If enabled, exception reports are written to syslog
+# Default value: off
+# syslog = on
+
+# If enabled, exception reports are written to systemd-journald
+# Default value: on
+# journald = off
+
+# Path to directory or file for writing exception reports.
+# Default value: <empty string = means no log file>
+# output = /tmp/
+
+# Comma separated list of exception types that are reported even
+# if they are caught.
+# Default value: <empty>
+# caught = java.lang.UnsatisfiedLinkError, java.lang.ClassCastException
+
+# Comma separated list of methods whose return values are
+# included in exception report.
+# Methods in the list must be static, without arguments and return
+# java.lang.String
+# Default value: empty
+#
+# http://mail.openjdk.java.net/pipermail/distro-pkg-dev/2014-March/026533.html
+# http://mail.openjdk.java.net/pipermail/distro-pkg-dev/2014-March/026551.html
+#
+debugmethod = net.sourceforge.jnlp.runtime.JNLPRuntime.getHistory

src/CMakeLists.txt

@@ -3,13 +3,15 @@ include_directories(${JAVA_INCLUDE_PATH} ${JAVA_INCLUDE_PATH2})
 
 pkg_check_modules(PC_JOURNALD REQUIRED libsystemd-journal)
 include_directories(${PC_LIBREPORT_INCLUDE_DIRS})
+include_directories(${PC_ABRT_INCLUDE_DIRS})
 include_directories(${PC_JOURNALD_INCLUDE_DIRS})
 
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -std=c99 -pedantic")
 set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -O0 -DVERBOSE")
 set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -DSILENT")
 
-set(AbrtChecker_SRCS abrt-checker.c jthrowable_circular_buf.c jthread_map.c)
+set(AbrtChecker_SRCS configuration.c abrt-checker.c
+        jthrowable_circular_buf.c jthread_map.c)
 
 add_library(AbrtChecker SHARED ${AbrtChecker_SRCS})
 set_target_properties(
@@ -18,6 +20,7 @@ set_target_properties(
         OUTPUT_NAME abrt-java-connector)
 
 target_link_libraries(AbrtChecker ${PC_LIBREPORT_LIBRARIES})
+target_link_libraries(AbrtChecker ${PC_ABRT_LIBRARIES})
 target_link_libraries(AbrtChecker ${PC_JOURNALD_LIBRARIES})
 
 install(TARGETS AbrtChecker DESTINATION ${LIB_INSTALL_DIR})