1. 安装native库

cloudera版本没有native
tar包中没有native库
http://archive.cloudera.com/cdh5/cdh/5/
rpm包中有native库，拷贝过去即可
http://archive.cloudera.com/cdh5/redhat/6/x86_64/cdh/5.3.2/RPMS/x86_64/

2. 编译连接

#include <stdio.h>
#include<unistd.h>
#include<string.h>
#include<stdlib.h>
#include "hdfs.h" 

int main(int argc, char **argv) {
    hdfsFS fs = hdfsConnect("10.35.0.36", 8020);
    const char* writePath = "/test/liudong_testfile.txt";
    hdfsFile writeFile = hdfsOpenFile(fs, writePath, O_WRONLY|O_CREAT, 0, 0, 0);
    if(!writeFile) {
        fprintf(stderr, "Failed to open %s for writing!\n", writePath);
        exit(-1);
    }
    char* buffer = "Hello, World!";
    tSize num_written_bytes = hdfsWrite(fs, writeFile, (void*)buffer, strlen(buffer)+1);
    if (hdfsFlush(fs, writeFile)) {
        fprintf(stderr, "Failed to 'flush' %s\n", writePath); 
        exit(-1);
    }
    hdfsCloseFile(fs, writeFile);
    printf("success");
}

g++ -o ./test ./test.cc
-I../include/hdfs
-L../lib/hdfs
-L/usr/java/jdk1.7.0_21/jre/lib/amd64/server
-lhdfs -ljvm

-I../include/hdfs
指出hdfs.h 所在的路径
-L../lib/hdfs
指出libhdfs.a所在的路径
-L/usr/java/jdk1.7.0_21/jre/lib/amd64/server
指出libjvm.so所在路径
-lhdfs -ljvm
指出连接libhdfs, libjvm

3. 运行

要特别注意classpath的设定
这个地方有一个陷阱, 如下方式是错误的：
export CLASSPATH=hadoop classpath
classpath必须直接包含jar文件，而不是用wildcard来匹配，注意jar文件最好不要重复

for jar_file in `find /usr/local/hadoop-cdh -name "*.jar"`;do
    jar_name=${jar_file##*/}
    echo ${CLASSPATH}|grep ${jar_name} > /dev/null 2>&1
    if [ $? -eq 1 ];then
        export CLASSPATH=${CLASSPATH}:${jar_file}
    fi
done