JoinPrefixUtils (druid-processing 30.0.1 API)

java.lang.Object
- org.apache.druid.segment.join.JoinPrefixUtils

```
public class JoinPrefixUtils
extends Object
```
Utility class for working with prefixes in join operations

Constructor Summary

Constructors
Constructor Description

JoinPrefixUtils()

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static void`	`checkPrefixesForDuplicatesAndShadowing(List<String> prefixes)`	Check if any prefixes in the provided list duplicate or shadow each other.
`static boolean`	`isPrefixedBy(String columnName, String prefix)`
`static String`	`unprefix(String columnName, String prefix)`	Removes the prefix on `columnName`.
`static String`	`validatePrefix(String prefix)`	Checks that "prefix" is a valid prefix for a join clause (see `JoinableClause.getPrefix()`) and, if so, returns it.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - JoinPrefixUtils
```
public JoinPrefixUtils()
```
- Method Detail
  - validatePrefix
```
public static String validatePrefix(@Nullable
                                    String prefix)
```
    Checks that "prefix" is a valid prefix for a join clause (see JoinableClause.getPrefix()) and, if so, returns it. Otherwise, throws an exception.
  - isPrefixedBy
```
public static boolean isPrefixedBy(String columnName,
                                   String prefix)
```
  - unprefix
```
public static String unprefix(String columnName,
                              String prefix)
```
    Removes the prefix on columnName. Must only be called if the column name is actually prefixed; i.e., if isPrefixedBy(String, String) would return true on the same arguments.
    
    Throws:
    
    IllegalArgumentException - if columnName does not start with prefix
  - checkPrefixesForDuplicatesAndShadowing
```
public static void checkPrefixesForDuplicatesAndShadowing(List<String> prefixes)
```
    Check if any prefixes in the provided list duplicate or shadow each other.
    
    Parameters:
    
    prefixes - A mutable list containing the prefixes to check. This list will be sorted by descending string length.