java - 如何在 OSGI 包中包含 C 代码

Question

我正在研究使用 Java native 接口(interface)的 OSGI 包。我使用这个 makefile 来构建 .so 模块:

#!/usr/bin/make -f
#
# Makefile for native stuff
#

# c files to compile
C_SOURCES   := sqrt.c

# the name of the library to build
LIBNAME     := sqrt

C_SOURCE_DIR    := src
C_GENSOURCE_DIR := src

TARGET_DIR  := ../../../target
C_BUILD_DIR    = $(TARGET_DIR)/native
JAVA_BUILD_DIR = $(TARGET_DIR)/classes

# the name of the file we build
TARGET      = $(JAVA_BUILD_DIR)/META-INF/lib/$(LIB_PREFIX)$(LIBNAME)$(LIB_EXTN)

# find the jdk. if this doesn't work for you, define JAVA_HOME in your
# environment or on the make command line
JAVA_HOME ?= /opt/jdk1.7.0_02

# classpath for javah
JAVAH_CLASSPATH = `cat $(TARGET_DIR)/compile-classpath`

# tools and options
CFLAGS = -Wall -fpic
CPPFLAGS = -I$(C_SOURCE_DIR) -I$(C_GENSOURCE_DIR) -Iinclude \
    -I$(JAVA_HOME)/include
JAVAH = /opt/jdk1.7.0_02/bin/javah
JAVAH_FLAGS += -classpath $(JAVAH_CLASSPATH)
JAVAH_CMD = $(JAVAH) $(JAVAH_FLAGS) $(OUTPUT_OPTION)
LDFLAGS = -shared
LINK.so = $(CC) $(LDFLAGS) $(LD_LIBS)

ifdef DEBUG
CFLAGS += -g
LDFLAGS += -g
endif

# os-dependent bits
UNAME := $(shell uname)

ifeq ($(UNAME),Linux)
LIB_PREFIX = lib
LIB_EXTN = .so
CPPFLAGS += -I$(JAVA_HOME)/include/linux
else
ifeq ($(findstring CYGWIN,$(UNAME)),CYGWIN)
LIB_PREFIX =
LIB_EXTN = .dll
CPPFLAGS += -I$(JAVA_HOME)/include/win32
else
f := $(error Platform $(UNAME) not supported)
endif
endif

# we look in $(C_SOURCE_DIR) for c files...
vpath %.c $(C_SOURCE_DIR)

# convenience variables
C_OBJFILES = $(addprefix $(C_BUILD_DIR)/,$(subst .c,.o,$(C_SOURCES)))

# default target
all: $(TARGET)

# rule to compile the .c files
$(C_BUILD_DIR)/%.o: %.c
    @mkdir -p `dirname $@`
    $(COMPILE.c) $(OUTPUT_OPTION) $<

# link the C objects into a shared library
$(TARGET): $(C_OBJFILES) $(LDLIBS)
    @mkdir -p `dirname $@`
    $(LINK.so) $(OUTPUT_OPTION) $^

# a rule to build the .h file with javah                    
$(C_GENSOURCE_DIR)/org_DX_57_osgi_NB_27_impl_Sqrt.h: $(JAVA_BUILD_DIR)/org/DX_57/osgi/NB_27/impl/Sqrt.class
    rm -f $@                
    $(JAVAH) $(JAVAH_FLAGS) $(OUTPUT_OPTION) org.DX_57.osgi.NB_27.impl.Sqrt

# the .o file depends on the .h file
$(C_BUILD_DIR)/sqrt.o: $(C_GENSOURCE_DIR)/org_DX_57_osgi_NB_27_impl_Sqrt.h

clean::
    rm -f $(C_OBJFILES)
    rm -f $(TARGET)
    rm -f $(C_BUILD_DIR)/jnirules.mak

此Makefile 成功生成头文件并编译.o 文件。问题是当编译 bundle 时，.so 文件并没有打包成 bundle。 这是 POM 文件的内容:

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.DX_57.osgi.NB_27</groupId>
        <artifactId>NB_27</artifactId>
        <version>1.0-SNAPSHOT</version>
        <relativePath>../pom.xml</relativePath>
    </parent>
    <artifactId>NB_27-impl</artifactId>
    <packaging>bundle</packaging>
    <name>NB_27-impl</name>
    <url>http://maven.apache.org</url>
    <dependencies>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>3.8.1</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.felix</groupId>
            <artifactId>org.osgi.core</artifactId>
            <version>1.0.0</version>
        </dependency>
        <dependency>
            <groupId>${pom.groupId}</groupId>
            <artifactId>NB_27-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
       <plugin>
        <artifactId>maven-antrun-plugin</artifactId>
        <executions>
          <execution>
           <id>build-native</id>
            <phase>process-classes</phase>
            <goals>
              <goal>run</goal>
            </goals>
            <configuration>
              <tasks>
                <property name="native.classpath" refid="maven.compile.classpath" />
                <echo file="${project.build.directory}/compile-classpath" message="${native.classpath}" />
                <exec dir="src/main/native" executable="make" failonerror="true" />
              </tasks>
            </configuration>
          </execution>
        </executions>
      </plugin>

            <plugin>
                <groupId>org.apache.felix</groupId>
                <artifactId>maven-bundle-plugin</artifactId>
                <extensions>true</extensions>
                <configuration>
                    <instructions>
                        <Import-Package>${pom.groupId}.api, org.osgi.framework, org.apache.commons.collections, org.apache.commons.collections.buffer</Import-Package>
                        <Bundle-SymbolicName>${pom.artifactId}</Bundle-SymbolicName>
                        <Bundle-Activator>${pom.groupId}.impl.NetworkBridgeApp</Bundle-Activator>
                    </instructions>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.3.2</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
    <groupId>org.DX_57.osgi.NB_27</groupId>
</project>

当我用 maven-assembly-plugin 替换 maven-bundle-plugin 和 maven-compiler-plugin 时， native 库包含在包中。我如何创建 OSGI 包并在构建期间包含 native 库？

Answer 1

我认为 Maven Bundle Plugin 没有针对 native 代码的特定规定，我认为您不需要它们:您需要的所有支持都已经存在。你需要

• 使用 <Include-Resource> 包含 native 库指令，和
• 包括Bundle-NativeCode说明中的 header ，就像您手动构建 list 时一样。