public class Test {
public Connection connection;
// 用HBaseconfiguration初始化配置信息是会自动加载当前应用的classpath下的hbase-site.xml
public static Configuration configuration = HBaseConfiguration.create();
public Test() throws Exception {
// 当然也可以手动加载配置文件，手动加载配置文件时要调用configuration的addResource方法
// configuration.addResource("hbase-site.xml");
connection = ConnectionFactory.createConnection(configuration);
}
public void createTable(String tableName, String... cf1) throws Exception {
Admin admin = connection.getAdmin();
//HTD需要TableName类型的tableName，创建TableName类型的tableName
TableName tbName = TableName.valueOf(tableName);
//判断表述否已存在，不存在则创建表
if (admin.tableExists(tbName)) {
System.err.println("表" + tableName + "已存在！");
return;
}
//通过HTableDescriptor创建一个HTableDescriptor将表的描述传到createTable参数中
HTableDescriptor HTD = new HTableDescriptor(tbName);
//为描述器添加表的详细参数
for (String cf : cf1) {
// 创建HColumnDescriptor对象添加表的详细的描述
HColumnDescriptor HCD = new HColumnDescriptor(cf);
HTD.addFamily(HCD);
}
//调用createtable方法创建表
admin.createTable(HTD);
}
public void deleteTable(String tableName) throws Exception {
Admin admin = connection.getAdmin();
//通过tableName创建表名
TableName tbName = TableName.valueOf(tableName);
//判断表是否存在，若存在就删除，不存在就退出
if (admin.tableExists(tbName)) {
//首先将表解除占用，否则无法删除
admin.disableTable(tbName);
//调用delete方法
admin.deleteTable(tbName);
System.err.println("表" + tableName + "已删除");
} else {
System.err.println("表" + tableName + "不存在！");
}
}
public void putData() throws Exception {
//通过表名获取tbName
TableName tbname = TableName.valueOf("t1");
//通过connection获取相应的表
Table table = connection.getTable(tbname);
//创建Random对象以作为随机参数
Random random = new Random();
//hbase支持批量写入数据，创建Put集合来存放批量的数据
List<Put> batput = new ArrayList<>();
for (int i = 0; i < 10; i++) {
//实例化put对象，传入行键
Put put = new Put(Bytes.toBytes("rowkey_" + i));
//调用addcolum方法，向f1列簇中添加字段
put.addImmutable(Bytes.toBytes("f1"), Bytes.toBytes("username"), Bytes.toBytes("un_" + i));
put.addImmutable(Bytes.toBytes("f1"), Bytes.toBytes("age"), Bytes.toBytes(random.nextInt(50) + 1));
put.addImmutable(Bytes.toBytes("f1"), Bytes.toBytes("birthday"), Bytes.toBytes("2017" + i));
put.addImmutable(Bytes.toBytes("f1"), Bytes.toBytes("phone"), Bytes.toBytes("phone:" + i));
put.addImmutable(Bytes.toBytes("f1"), Bytes.toBytes("邮箱"), Bytes.toBytes("邮箱:" + i));
//将测试数据添加到list中
batput.add(put);
}
//调用put方法将list中的测试数据写入hbase
table.put(batput);
System.err.println("数据插入完成！");
}
public void getData() throws Exception {
//获取想要查询的表的TableName
TableName tbname = TableName.valueOf("t1");
//通过tbName获得Table对象
Table table = connection.getTable(tbname);
//创建Get的集合以承接查询的条件
List<Get> gets = new ArrayList<Get>();
//循环五次，取前五个测试数据
for (int i = 0; i < 5; i++) {
//就将查询条件放入get对象中
Get get = new Get(Bytes.toBytes("rowkey_" + i));
//将get对象放入聚合
gets.add(get);
}
//调用table.get方法传入查询条件，获得查询的结果的数组
Result[] results = table.get(gets);
//遍历结果数组，利用CellScanner配合cellUtil获得对应的数据
for (Result result : results) {
//调用result.cellscanner创建scanner对象
CellScanner cellScanner = result.cellScanner();
//遍历结果集，取出查询结果，
//如果存在下一个cell则advandce方法返回true，且current方法会返回一个有效的cell，可以当作循环条件
while (cellScanner.advance()) {
//current方法返回一个有效的cell
Cell cell = cellScanner.current();
//使用CellUtil调用相应的方法获取想用的数据，并利用Bytes.toString方法将结果转换为string输出
String family = Bytes.toString(CellUtil.cloneFamily(cell));
String qualify = Bytes.toString(CellUtil.cloneQualifier(cell));
String rowkey = Bytes.toString(CellUtil.cloneRow(cell));
String value = Bytes.toString(CellUtil.cloneValue(cell));
System.err.println(family + "_" + qualify + "_" + rowkey + "_" + value);
}
}
}
public void getData1() throws Exception {
TableName tbname = TableName.valueOf("bd14:fromJava");
Table table = connection.getTable(tbname);
List<Get> gets = new ArrayList<>();
for (int i = 0; i < 5; i++) {
Get get = new Get(Bytes.toBytes("rowkey_" + i));
gets.add(get);
}
Result[] results = table.get(gets);
for (Result result : results) {
NavigableMap<byte[], NavigableMap<byte[], NavigableMap<Long, byte[]>>> map = result.getMap();
for (byte[] cf : map.keySet()) {
NavigableMap<byte[], NavigableMap<Long, byte[]>> valueWithColumnQualify = map.get(cf);
for (byte[] columnQualify : valueWithColumnQualify.keySet()) {
NavigableMap<Long, byte[]> valueWithTimestamp = valueWithColumnQualify.get(columnQualify);
for (Long ts : valueWithTimestamp.keySet()) {
byte[] value = valueWithTimestamp.get(ts);
String rowKey = Bytes.toString(result.getRow());
String columnFamily = Bytes.toString(cf);
String columnqualify = Bytes.toString(columnQualify);
String timestamp = new Date(ts) + "";
String values = Bytes.toString(columnQualify);
System.out.println(rowKey + "-" + columnFamily + "-" + columnqualify + "-" + timestamp + "-" + values);
}
}
}
}
}
public void getData2() throws Exception {
TableName tbname = TableName.valueOf("bd14:fromJava");
Table table = connection.getTable(tbname);
List<Get> gets = new ArrayList<>();
for (int i = 0; i < 5; i++) {
Get get = new Get(Bytes.toBytes("rowkey_" + i));
gets.add(get);
}
Result[] results = table.get(gets);
//遍历结果对象results
for (Result result : results) {
//嵌套遍历result获取cell
for (Cell cell : result.listCells()) {
//使用CellUtil工具类直接获取cell中的数据
String family = Bytes.toString(CellUtil.cloneFamily(cell));
String qualify = Bytes.toString(CellUtil.cloneQualifier(cell));
String rowkey = Bytes.toString(CellUtil.cloneRow(cell));
String value = Bytes.toString(CellUtil.cloneValue(cell));
System.err.println(family + "_" + qualify + "_" + rowkey + "_" + value);
}
}
}
public void updateData(String tableName, String rowKey, String family, String columkey, String updatedata) throws Exception {
//hbase中更新数据同样采用put方法，在相同的位置put数据，则在查询时只会返回时间戳较新的数据
//且在文件合并时会将时间戳较旧的数据舍弃
Put put = new Put(Bytes.toBytes(rowKey));
//将新数据添加到put中
put.addImmutable(Bytes.toBytes(family), Bytes.toBytes(columkey), Bytes.toBytes(updatedata));
Table table = connection.getTable(TableName.valueOf(tableName));
//将put写入HBase
table.put(put);
}
//删除某条记录
public void deleteData(String tableName,String rowKey,String family, String columkey) throws Exception{
Table table = connection.getTable(TableName.valueOf(tableName));
//创建delete对象
Delete deletData= new Delete(Bytes.toBytes(rowKey));
//将要删除的数据的准确坐标添加到对象中
deletData.addColumn(Bytes.toBytes(family), Bytes.toBytes(columkey));
//删除表中数据
table.delete(deletData);
}
//删除一行数据
public void deleteRow(String tableName,String rowKey) throws Exception{
Table table = connection.getTable(TableName.valueOf(tableName));
//通过行键删除一整行的数据
Delete deletRow= new Delete(Bytes.toBytes(rowKey));
table.delete(deletRow);
}
public static void main(String[] args) {
try {
Test test = new Test();
test.createTable("t1", "f1");
// test.putData();
} catch (Exception e) {
e.printStackTrace();
}
}
}