环境搭完了，不知道怎样引jar包，怎样调用的看这里！ ps. 不涉及HBase原理详解，那个之后单独弄一篇
Let’s go!
Java IDE选用的是 eclipse， 用Intellij IDE的也差不多， 当然用sublime、vim、Emacs等的大神请绕道哈
下载eclipse
下载的版本是 Eclipse IDE for Java Developers， eclipse-java-mars-2-linux-gtk-x86_64.tar.gz
用java ee的更好， 这里只是符合大众之前在windows下的使用习惯。
导入jar包依赖
cd 进eclipse 目录
./eclipse 启动eclipse
先新建个工程吧
在工程上点击右键，选择Properties
选择java Build Path -> Libraries
点击Add Livrary -> User Library -> next
这里我已经弄好了哈，你们忽略，就当没弄好，接下来关键了
点击右侧 UserLibrary -> new
先建关于hadoop的依赖
自己取个响亮又大方的名字（关于hadoop，例如hdfslib，hbase的另建一个），我作为示意取为test
点击右侧 Add External JARS
接下来是几个路径了，我就不配图了
以下用$HADOOP_HOME代表hadoop安装目录
我的是/usr/local/hadoop
$HADOOP_HOME/share/hadoop/hdfs/hadoop-hdfs-2.6.0.jar
$HADOOP_HOME/share/hadoop/hdfs/lib 所有
$HADOOP_HOME/share/hadoop/common/hadoop-common-2.6.0.jar
$HADOOP_HOME/share/hadoop/common/lib 所有
finish
接下来是HBase
同样的过程，新建一个usr library ，命名为hbase或者其他
HBase 简单一点，导入 安装目录/lib 下所有jar包即可
Hadoop hdfs Java Demo
package test;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
public class HdfsDemo {
public static void main(String[] args) throws IOException {
// TODO Auto-generated method stub
String file = "hdfs://localhost:9000/homework/hw1/tpch/lineitem.tbl";
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(URI.create(file),conf);
Path path = new Path(file);
FSDataInputStream in_stream = fs.open(path);
BufferedReader in = new BufferedReader(new InputStreamReader(in_stream));
String s;
while ((s = in.readLine())!=null) {
System.out.println(s);
}
in.close();
fs.close();
}
}
做作业的话，首先要将hw1文件夹上传到hdfs根目录
HBase Java Demo
package test;
import java.io.IOException;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Put;
public class HBaseTest {
public static void main(String[] args) throws MasterNotRunningException, ZooKeeperConnectionException, IOException {
// TODO Auto-generated method stub
//create table descriptor
String tableName = "mytable";
HTableDescriptor htd = new HTableDescriptor(TableName.valueOf(tableName));
//create column descriptor
HColumnDescriptor cf = new HColumnDescriptor("mycf");
htd.addFamily(cf);
//confugure HBase
Configuration configuration = HBaseConfiguration.create();
HBaseAdmin hAdmin = new HBaseAdmin(configuration);
hAdmin.createTable(htd);
hAdmin.close();
//put "mytable","abc","mycf:a","789"
HTable table = new HTable(configuration, tableName);
Put put = new Put("abc".getBytes());
put.add("mycf".getBytes(), "a".getBytes(), "789".getBytes());
table.put(put);
table.close();
System.out.println("put successfully!");
}
}