import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import java.io.IOException;
public class ExampleForHbase{
public static Configuration configuration;
public static Connection connection;
public static Admin admin;
//主函数中的语句请逐句执行，只需删除其前的//即可，如：执行insertRow时请将其他语句注释
public static void main(String[] args)throws IOException{
// createTable("Student",new String[]{"S_Name","S_Sex","S_Age","C_No","C_Credit","SC_Score"});
//创建一个表，表名为Score，列族为sname,course
//deleteRow("Student", "2015003", "", "");
//在Score表中插入一条数据，其行键为95001,sname为Mary（因为sname列族下没有子列所以第四个参数为空）
//等价命令：put 'Score','95001','sname','Mary'
/* insertRow("Student", "2015001", "S_Name", "", "Zhangsan");
insertRow("Student", "2015001", "S_Sex", "", "male");
insertRow("Student", "2015001", "S_Age", "", "23");
insertRow("Student", "2015001", "C_No", "Math", "123001");
insertRow("Student", "2015001", "C_Credit", "Math", "2.0");
insertRow("Student", "2015001", "C_No", "English", "123003");
insertRow("Student", "2015001", "C_Credit", "English", "3.0");
insertRow("Student", "2015001", "SC_Score", "123001", "86");
insertRow("Student", "2015001", "SC_Score", "123003", "69");
insertRow("Student", "2015002", "S_Name", "", "Mary");
insertRow("Student", "2015002", "S_Sex", "", "female");
insertRow("Student", "2015002", "S_Age", "", "22");
insertRow("Student", "2015002", "C_No", "Computer Science", "123002");
insertRow("Student", "2015002", "C_Credit", "Computer Science", "5.0");
insertRow("Student", "2015002", "C_No", "English", "123003");
insertRow("Student", "2015002", "C_Credit", "English", "3.0");
insertRow("Student", "2015002", "SC_Score", "123002", "77");
insertRow("Student", "2015002", "SC_Score", "123003", "99");
insertRow("Student", "2015003", "S_Name", "", "Lisi");
insertRow("Student", "2015003", "S_Sex", "", "male");
insertRow("Student", "2015003", "S_Age", "", "24");
insertRow("Student", "2015003", "C_No", "Computer Science", "123002");
insertRow("Student", "2015003", "C_Credit", "Computer Science", "5.0");
insertRow("Student", "2015003", "C_No", "Math", "123001");
insertRow("Student", "2015003", "C_Credit", "Math", "2.0");
insertRow("Student", "2015003", "SC_Score", "123002", "95");
insertRow("Student", "2015003", "SC_Score", "123001", "98");
*/
//modifyData("Student", "2015001", "S_Name", "Wangwu");
//在Score表中插入一条数据，其行键为95001,course:Math为88（course为列族，Math为course下的子列）
//等价命令：put 'Score','95001','score:Math','88'
//insertRow("Score", "95001", "course", "Math", "88");
//在Score表中插入一条数据，其行键为95001,course:English为85（course为列族，English为course下的子列）
//等价命令：put 'Score','95001','score:English','85'
//insertRow("Score", "95001", "course", "English", "85");
//1、删除Score表中指定列数据，其行键为95001,列族为course，列为Math
//执行这句代码前请deleteRow方法的定义中，将删除指定列数据的代码取消注释注释，将删除制定列族的代码注释
//等价命令：delete 'Score','95001','score:Math'
//deleteRow("Score", "95001", "course", "Math");
//2、删除Score表中指定列族数据，其行键为95001,列族为course（95001的Math和English的值都会被删除）
//执行这句代码前请deleteRow方法的定义中，将删除指定列数据的代码注释，将删除制定列族的代码取消注释
//等价命令：delete 'Score','95001','score'
//deleteRow("Score", "95001", "course", "");
//3、删除Score表中指定行数据，其行键为95001
//执行这句代码前请deleteRow方法的定义中，将删除指定列数据的代码注释，以及将删除制定列族的代码注释
//等价命令：deleteall 'Score','95001'
// deleteRow("Student", "2015003", "", "");
//查询Score表中，行键为95001，列族为course，列为Math的值
//getData("Score", "95001", "course", "Math");
//查询Score表中，行键为95001，列族为sname的值（因为sname列族下没有子列所以第四个参数为空）
//getData("Student","2015001", "C_Credit", "English");
//删除Score表
// deleteTable("Student");
}
//建立连接
public static void init(){
configuration = HBaseConfiguration.create();
configuration.set("hbase.rootdir","hdfs://localhost:9000/hbase");
try{
connection = ConnectionFactory.createConnection(configuration);
admin = connection.getAdmin();
}catch (IOException e){
e.printStackTrace();
}
}
//关闭连接
public static void close(){
try{
if(admin != null){
admin.close();
}
if(null != connection){
connection.close();
}
}catch (IOException e){
e.printStackTrace();
}
}
/**
* 建表。HBase的表中会有一个系统默认的属性作为主键，主键无需自行创建，默认为put命令操作中表名后第一个数据，因此此处无需创建id列
* @param myTableName 表名
* @param colFamily 列族名
* @throws IOException
*/
public static void createTable(String myTableName,String[] colFamily) throws IOException {
init();
TableName tableName = TableName.valueOf(myTableName);
if(admin.tableExists(tableName)){
admin.disableTable(tableName);
admin.deleteTable(tableName); //删除原来的表
System.out.println("所创建表已存在!");
HTableDescriptor hTableDescriptor = new HTableDescriptor(tableName);
for(String str:colFamily){
HColumnDescriptor hColumnDescriptor = new HColumnDescriptor(str);
hTableDescriptor.addFamily(hColumnDescriptor);
}
admin.createTable(hTableDescriptor);
System.out.println("create table success");
}
else {
HTableDescriptor hTableDescriptor = new HTableDescriptor(tableName);
for(String str:colFamily){
HColumnDescriptor hColumnDescriptor = new HColumnDescriptor(str);
hTableDescriptor.addFamily(hColumnDescriptor);
}
admin.createTable(hTableDescriptor);
System.out.println("创建成功");
}
close();
}
/**
* 删除指定表
* @param tableName 表名
* @throws IOException
*/
public static void deleteTable(String tableName) throws IOException {
init();
TableName tn = TableName.valueOf(tableName);
if (admin.tableExists(tn)) {
admin.disableTable(tn);
admin.deleteTable(tn);
}
close();
}
/**
* 查看已有表
* @throws IOException
*/
public static void listTables() throws IOException {
init();
HTableDescriptor hTableDescriptors[] = admin.listTables();
for(HTableDescriptor hTableDescriptor :hTableDescriptors){
System.out.println(hTableDescriptor.getNameAsString());
}
close();
}
/**
* 向某一行的某一列插入数据
* @param tableName 表名
* @param rowKey 行键
* @param colFamily 列族名
* @param col 列名（如果其列族下没有子列，此参数可为空）
* @param val 值
* @throws IOException
*/
public static void insertRow(String tableName,String rowKey,String colFamily,String col,String val) throws IOException {
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Put put = new Put(rowKey.getBytes());
put.addColumn(colFamily.getBytes(), col.getBytes(), val.getBytes());
table.put(put);
table.close();
System.out.println("插入成功");
close();
}
/**
* 删除数据
* @param tableName 表名
* @param rowKey 行键
* @param colFamily 列族名
* @param col 列名
* @throws IOException
*/
public static void deleteRow(String tableName,String rowKey,String colFamily,String col) throws IOException {
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Delete delete = new Delete(rowKey.getBytes());
//删除指定列族的所有数据
//delete.addFamily(colFamily.getBytes());
//删除指定列的数据
//delete.addColumn(colFamily.getBytes(), col.getBytes());
table.delete(delete);
table.close();
System.out.println("删除成功");
close();
}
/**
* 根据行键rowkey查找数据
* @param tableName 表名
* @param rowKey 行键
* @param colFamily 列族名
* @param col 列名
* @throws IOException
*/
public static void getData(String tableName,String rowKey,String colFamily,String col)throws IOException{
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Get get = new Get(rowKey.getBytes());
get.addColumn(colFamily.getBytes(),col.getBytes());
Result result = table.get(get);
showCell(result);
table.close();
close();
}
/*
* 修改某一列的数据
*/
public static void modifyData(String tableName,String rowKey,String colFamily,String col,String val)throws IOException{
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Put put = new Put(rowKey.getBytes());
put.addColumn(colFamily.getBytes(), col.getBytes(), val.getBytes());
table.put(put);
table.close();
System.out.println("修改成功");
close();
}
/* public static void insertRow(String tableName,String rowKey,String colFamily,String col,String val) throws IOException {
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Put put = new Put(rowKey.getBytes());
put.addColumn(colFamily.getBytes(), col.getBytes(), val.getBytes());
table.put(put);
table.close();
System.out.println("插入成功");
close();
}
*/
/**
* 格式化输出
* @param result
*/
public static void showCell(Result result){
Cell[] cells = result.rawCells();
for(Cell cell:cells){
System.out.println("RowName:"+new String(CellUtil.cloneRow(cell))+" ");
System.out.println("Timetamp:"+cell.getTimestamp()+" ");
System.out.println("column Family:"+new String(CellUtil.cloneFamily(cell))+" ");
System.out.println("row Name:"+new String(CellUtil.cloneQualifier(cell))+" ");
System.out.println("value:"+new String(CellUtil.cloneValue(cell))+" ");
}
}
}
网友评论