table 自行更改包名
package table;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.*;
import org.apache.hadoop.hbase.client.*;
import java.io.IOException;
student 自行更改类名
public class student{
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{
创建一个表,表名为mxy,列族为name,age,sex,course
// createTable("mxy",new String[]{"name","age","sex","course"});
//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' //在终端运行的命令
insertRow("mxy", "95001", "name","","mxy");
//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("mxy", "95001", "age", "", "18");
//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("mxy", "95003", "course", "English", "85");
insertRow("mxy", "95002", "course", "Math", "59");
//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("mxy", "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("mxy", "95001","","");
//查询Score表中,行键为95001,列族为course,列为Math的值
//getData("mxy", "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("mxy", "95001","course","");
//删除mxy表
//deleteTable("mxy");
// 追加插入(将原有value的后面追加新的value,如原有value=a追加value=bc则最后的value=abc)
//appendData("mxy","95003","course","English","1");
//全局扫描显示
scanTable("mxy");
}
全局扫描显示
/**
* 全表扫描
* @param result
*/
public static void scanTable(String tableName) throws IOException {
init();
Table table = connection.getTable(TableName.valueOf(tableName));
Scan scan = new Scan();
ResultScanner results = table.getScanner(scan);
for (Result result : results) {
for (Cell cell : result.rawCells()) {
System.out.println(
"行键:" + new String(CellUtil.cloneRow(cell)) + "\t" +
"列族:" + new String(CellUtil.cloneFamily(cell)) + "\t" +
"列名:" + new String(CellUtil.cloneQualifier(cell)) + "\t" +
"值:" + new String(CellUtil.cloneValue(cell)) + "\t" +
"时间戳:" + cell.getTimestamp());
}
}
}
// 追加插入(将原有value的后面追加新的value,如原有value=a追加value=bc则最后的value=abc)
public static void appendData(String tableName, String rowKey, String columnFamily, String column, String value)
throws IOException {
init();
// 获取表
Table table = connection.getTable(TableName.valueOf(tableName));
// 通过rowkey创建一个append对象
Append append = new Append(rowKey.getBytes());
// 在append对象中设置列族、列、值
append.add(columnFamily.getBytes(), column.getBytes(), value.getBytes());
// 追加数据
table.append(append);
// 关闭资源
table.close();
}
//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)){
System.out.println("talbe is exists!");
}else {
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");
}
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();
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();
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();
}
/**
* 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))+" ");
}
}
}