Package org.apache.tika.pipes.core.config

Class ConfigMerger

java.lang.Object

org.apache.tika.pipes.core.config.ConfigMerger

public class ConfigMerger
extends Object

Utility for merging configuration overrides with existing Tika JSON configuration.

This class centralizes the config generation logic that was previously duplicated in:

• PipesForkParser.generateJsonConfig()
• TikaServerProcess.createDefaultConfig() and ensureServerComponents()
• TikaAsyncCLI.PluginsWriter and ensurePluginRoots()

Key design decisions:

• Uses UUID-based names for internal fetchers/emitters to avoid conflicts with user-configured components
• Returns the merged config and generated names so callers can use them
• Preserves existing config sections when merging
• merge(java.nio.file.Path, org.apache.tika.pipes.core.config.ConfigOverrides) stays in memory; mergeOrCreate(java.nio.file.Path, org.apache.tika.pipes.core.config.ConfigOverrides) writes a temp file that is marked for deletion on JVM exit

Example usage:

 ConfigOverrides overrides = ConfigOverrides.builder()
     .addFetcher("my-fetcher", "file-system-fetcher",
         Map.of("basePath", "/tmp/input"))
     .setPipesConfig(4, null)
     .setEmitStrategy(EmitStrategy.PASSBACK_ALL)
     .build();

 MergedConfig merged = ConfigMerger.merge(existingConfigPath, overrides);
 TikaJsonConfig tikaJsonConfig = merged.load();
 PipesParser.load(tikaJsonConfig, PipesConfig.load(tikaJsonConfig));
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	ConfigMerger.MergedConfig	Result of an in-memory config merge.
static final record	ConfigMerger.MergeResult	Result of a config merge operation.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	GENERATED_EMITTER_PREFIX
static final String	GENERATED_FETCHER_PREFIX	Ids for host components the caller did not name (PipesForkParser's fetcher, for one).

Method Summary

Modifier and Type	Method	Description
static ConfigMerger.MergedConfig	merge(Path existingConfig, ConfigOverrides overrides)	Like mergeOrCreate(java.nio.file.Path, org.apache.tika.pipes.core.config.ConfigOverrides) but in memory: nothing is written to disk.
static ConfigMerger.MergeResult	mergeOrCreate(Path existingConfig, ConfigOverrides overrides)	Merges overrides with an existing config, or creates a new config if none exists.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

GENERATED_FETCHER_PREFIX

public static final String GENERATED_FETCHER_PREFIX

Ids for host components the caller did not name (PipesForkParser's fetcher, for one). They live in the reserved namespace like every other host-wired component: the UUID makes them unguessable, but that is not the same as being unnameable.

See Also:

• Constant Field Values

GENERATED_EMITTER_PREFIX

public static final String GENERATED_EMITTER_PREFIX

See Also:

• Constant Field Values

Method Details

mergeOrCreate

public static ConfigMerger.MergeResult mergeOrCreate(Path existingConfig,
 ConfigOverrides overrides)
                                              throws IOException

Merges overrides with an existing config, or creates a new config if none exists.

For fetchers and emitters without explicit IDs in the overrides, UUID-based names are generated to avoid conflicts with user-configured components.

Parameters:

existingConfig - path to existing config (may be null)

overrides - the overrides to apply

Returns:

MergeResult containing path to merged config and generated fetcher ID

Throws:

IOException - if file operations fail

merge

public static ConfigMerger.MergedConfig merge(Path existingConfig,
 ConfigOverrides overrides)
                                       throws IOException

Like mergeOrCreate(java.nio.file.Path, org.apache.tika.pipes.core.config.ConfigOverrides) but in memory: nothing is written to disk.

Parameters:

existingConfig - path to existing config (may be null)

overrides - the overrides to apply

Returns:

the merged config JSON, env references unresolved, and the generated ids

Throws:

IOException - if the existing config can't be read