C++库的源代码位于：
hadoop-2.4.0-src/hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs
这里提供一个直接对这些源文件进行编译的makefile，编译后将打包命名为libhdfs.a. makefile内容为：
CC = gcc
DEFINES = -DG_ARCH_X86_64
CFLAGS += -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT $(DEFINES)
CXXFLAGS += -pipe -O3 -D_REENTRANT $(DEFINES) -rdynamic
AR = ar cqs
LFLAGS = -rdynamic
OBJECTS = exception.o expect.o hdfs.o jni_helper.o native_mini_dfs.o
TARGET = libhdfs.a
#command, don't change
CHK_DIR_EXISTS= test -d
DEL_FILE = rm -f
first: all
####### Implicit rules
.SUFFIXES: .o .c .cpp .cc .cxx .C .cu
.cpp.o:
$(CXX) -c $(CXXFLAGS) $(INCPATH) -o "$@" "$<"
.cc.o:
$(CXX) -c $(CXXFLAGS) $(INCPATH) -o "$@" "$<"
.cxx.o:
$(CXX) -c $(CXXFLAGS) $(INCPATH) -o "$@" "$<"
.C.o:
$(CXX) -c $(CXXFLAGS) $(INCPATH) -o "$@" "$<"
.c.o:
$(CC) -c $(CFLAGS) $(INCPATH) -o "$@" "$<"
####### Build rules
all: $(AR)
$(AR): $(TARGET)
$(TARGET): $(OBJECTS)
$(AR) $(TARGET) $(OBJECTS)
clean:
-$(DEL_FILE) $(OBJECTS) $(TARGET)
保存好后，直接make. 编译信息如下：
gcc -c -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT -DG_ARCH_X86_64 -o "exception.o" "exception.c"
gcc -c -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT -DG_ARCH_X86_64 -o "expect.o" "expect.c"
gcc -c -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT -DG_ARCH_X86_64 -o "hdfs.o" "hdfs.c"
gcc -c -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT -DG_ARCH_X86_64 -o "jni_helper.o" "jni_helper.c"
gcc -c -fPIC -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -pipe -O3 -D_REENTRANT -DG_ARCH_X86_64 -o "native_mini_dfs.o" "native_mini_dfs.c"
ar cqs libhdfs.a exception.o expect.o hdfs.o jni_helper.o native_mini_dfs.o
接下来测试一下这个库能不能用。进入以下目录
hadoop-2.4.0-src/hadoop-hdfs-project/hadoop-hdfs/src/main/native/libhdfs/test
找到测试源代码，对该文件夹中所有测试代码进行编译.这里再提供一个简单的makefile，内容如下：
LIBS = -L$(JAVA_HOME)/jre/lib/amd64/server/ -ljvm -L../ -lhdfs
INCPATH = -I$(JAVA_HOME)/include -I$(JAVA_HOME)/include/linux -I. -I..
all:
gcc -o hdfs_ops test_libhdfs_ops.c $(INCPATH) $(LIBS)
gcc -o hdfs_read test_libhdfs_read.c $(INCPATH) $(LIBS)
gcc -o hdfs_write test_libhdfs_write.c $(INCPATH) $(LIBS)
gcc -o hdfs_zerocopy test_libhdfs_zerocopy.c $(INCPATH) $(LIBS)
直接make,编译信息如下：
gcc -o hdfs_ops test_libhdfs_ops.c -I/d0/data/lichao/software/java/jdk1.7.0_55/include -I/d0/data/lichao/software/java/jdk1.7.0_55/include/linux -I. -I.. -L/d0/data/lichao/software/java/jdk1.7.0_55/jre/lib/amd64/server/ -ljvm -L../ -lhdfs
gcc -o hdfs_read test_libhdfs_read.c -I/d0/data/lichao/software/java/jdk1.7.0_55/include -I/d0/data/lichao/software/java/jdk1.7.0_55/include/linux -I. -I.. -L/d0/data/lichao/software/java/jdk1.7.0_55/jre/lib/amd64/server/ -ljvm -L../ -lhdfs
gcc -o hdfs_write test_libhdfs_write.c -I/d0/data/lichao/software/java/jdk1.7.0_55/include -I/d0/data/lichao/software/java/jdk1.7.0_55/include/linux -I. -I.. -L/d0/data/lichao/software/java/jdk1.7.0_55/jre/lib/amd64/server/ -ljvm -L../ -lhdfs
gcc -o hdfs_zerocopy test_libhdfs_zerocopy.c -I/d0/data/lichao/software/java/jdk1.7.0_55/include -I/d0/data/lichao/software/java/jdk1.7.0_55/include/linux -I. -I.. -L/d0/data/lichao/software/java/jdk1.7.0_55/jre/lib/amd64/server/ -ljvm -L../ -lhdfs
我们随便生成一个文件，包含1到10这10个数字，并加载到hdfs文件系统。
seq 1 10 > tmpfile
hadoop fs -mkdir /data
hadoop fs -put tmpfile /data
hadoop fs -cat /data/tmpfile
1
2
3
4
5
6
7
8
9
10
ok。现在运行生成的hdfs_read程序，测试一下hdfs的64位C++接口：
./hdfs_read /data/tmpfile 21 32
运行信息如下：
log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
1
2
3
4
5
6
7
8
9
10
--------------------------------------分割线 --------------------------------------
Ubuntu 13.04上搭建Hadoop环境 http://www.linuxidc.com/Linux/2013-06/86106.htm
Ubuntu 12.10 +Hadoop 1.2.1版本集群配置 http://www.linuxidc.com/Linux/2013-09/90600.htm
Ubuntu上搭建Hadoop环境（单机模式+伪分布模式） http://www.linuxidc.com/Linux/2013-01/77681.htm
Ubuntu下Hadoop环境的配置 http://www.linuxidc.com/Linux/2012-11/74539.htm
单机版搭建Hadoop环境图文教程详解 http://www.linuxidc.com/Linux/2012-02/53927.htm
