AlternateResultProvider

Background and Use Cases

FineReport has a built-in standard dataset cache strategy. When the built-in strategy cannot meet requirements, developers can implement AlternateResultProvider to define a custom caching solution tailored to their business needs.

Additionally, after a fill-in operation modifies a data table, the associated cache needs to be invalidated. This interface parses connection, schema, and table information and matches cache SQL keywords (from, join, union, into) to help synchronize cache invalidation with fill-in configuration changes.

This interface can also be used to register externally accessible cache strategies between plugins, reducing inter-plugin coupling.

Interface Definition

package com.fr.stable.fun;

import com.fr.stable.fun.mark.Mutable;

public interface AlternateResultProvider<K, V> extends Mutable {
    int CURRENT_LEVEL = 1;
    String MARK_STRING = "AlternateResultProvider";

    boolean accept(Class<?> keyClz, Class<?> valClz);
    V get(K key);
    void put(K key, V value);
    void remove(K key);
    <E> void removeBy(E extraKey);
}

package com.fr.stable.fun.impl;

import com.fr.stable.fun.AlternateResultProvider;

@API(level = AlternateResultProvider.CURRENT_LEVEL)
public abstract class AbstractAlternateResultProvider<K, V>
        implements AlternateResultProvider<K, V> {

    public int currentAPILevel() {
        return CURRENT_LEVEL;
    }

    public String mark4Provider() {
        return MARK_STRING;
    }

    @Override
    public <E> void removeBy(E extraKey) {
        K[] matchedKeys = matchedKeys(extraKey);
        if (ArrayUtils.isNotEmpty(matchedKeys)) {
            for (K k : matchedKeys(extraKey)) {
                remove(k);
            }
        }
    }

    public abstract <E> K[] matchedKeys(E extraKey);
}

Supported Versions

Plugin Registration

Add the following node in plugin.xml:

<extra-core>
    <AlternateResultProvider class="your class name"/>
</extra-core>

How It Works

As shown in DmlController and SynchronizedLiveDataModelUtils, the shared dataset cache retrieval logic queries plugin implementations first, falling back to the product's built-in cache. When a fill-in operation triggers cache invalidation, the system calls the corresponding plugin method to remove cache entries.

Retrieval method:

Set<AlternateResultProvider> set = ExtraClassManager.getInstance().getArray(AlternateResultProvider.XML_TAG);

Useful Links

• Demo: demo-alternate-result-provider