向HDFS文件append新内容

FileSystem hdfs = FileSystem.get(conf);
FSDataOutputStream out;
if(!hdfs.exists(fpath))out = hdfs.create(fpath);
else out = hdfs.append(fpath);
out.writeChars(context.getBytes());  //context为新增内容
out.close();
hdfs.close();

<property>
<name>dfs.support.append</name>
<value>true</value>
</property>

java.io.IOException: Append to hdfs not supported. Please refer to dfs.support.append configuration parameter.