George Opritescu ♥ Developer from somewhere

spring devtools idea settings

Problem: code not getting reloaded when something changes.

Solution: found here

add devtools to your dependencies
go to Preferences -> Build, execution, deployment -> Compiler and check “Build project automatically”
press cmd-shift-a , and select registry
find and check compiler.automake.allow.when.app.running

// some code here

postgres reassign owned

Problem: wanted to change everything owned by one user to be owned by another user.

Solution: found here

reassign owned by old_user_name to new_user_name;

postgres pg sql

generate pem file from crt and key

Problem: have a .key and a .crt and want to generate a .pem file from them.

Solution:

found here: a simple cat will do

cat server.crt server.key > server.includespk.pem

ssl pem crt

ssh log files on centos

Problem: want to see logs for failed ssh attempts on CentOS.

Solution: look at /var/log/secure

ssh linux centos

java deserialization with jackson

Been debugging a deserialization issue for 3 hours. Turns out I had this in my code:

import org.codehaus.jackson.annotate.JsonProperty;
import org.codehaus.jackson.annotate.JsonSetter;

When, it should have been these:

import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;

java jackson spring spring boot

javascript format currency with intl

Problem:

Solution:

step 1

// some code here

hbase scan example

Problem: want to perform a scan on a table, and list the values.

Solution:

        Scan scan = new Scan();
        ResultScanner scanner = someTable.getScanner(scan);

        for(Result row : scanner) {

            List<Cell> cells = row.listCells();

            for(Cell c : cells) {
                byte columnFamily[] = CellUtil.cloneFamily(c);
                byte qualifier[] = CellUtil.cloneQualifier(c);
                byte value[] = CellUtil.cloneValue(c);
                System.out.println("columnFamily:" + Bytes.toString(columnFamily) +
                    " qualifier:" + Bytes.toString(qualifier) + " value:" + Bytes.toString(value));
            }
        }

java hbase

java hbase obtain column families for a particular table

Problem: want to obtain column families for a particular table.

Solution:

        Connection conn = ConnectionFactory.createConnection(config);
        Admin admin = conn.getAdmin();

        TableName transactionTableName = TableName.valueOf("some_table");
        HTableDescriptor tableDesc = admin.getTableDescriptor(transactionTableName);
        // this will contain all of them
        HColumnDescriptor colDesc[] = tableDesc.getColumnFamilies();

java hbase

git merge unrelated histories

Problem: want to merge 2 branches that don’t share a common history.

Solution:

git merge --allow-unrelated-histories somebranch

git

view principals in a kerberos keytab file

Problem: want to see principals in a keytab file.

Solution:

start ktutil

ktutil

read your keytab file:

ktutil:  read_kt /path/to/some.keytab

list them:

ktutil: list

kerberos