Validate Query API

A ValidateQueryRequest requires one or more indices on which the query is validated. If no index is provided the request is executed on all indices.

ValidateQueryRequest request = new ValidateQueryRequest(index); 

In addition it also needs the query that needs to be validated. The query can be built using the QueryBuilders utility class. The following code snippet builds a sample boolean query.

QueryBuilder builder = QueryBuilders
    .boolQuery() 
    .must(QueryBuilders.queryStringQuery("*:*"))
    .filter(QueryBuilders.termQuery("user", "kimchy"));
request.query(builder); 

The following arguments can optionally be provided:

request.explain(true); 

By default, the request is executed on a single shard only, which is randomly selected. The detailed explanation of the query may depend on which shard is being hit, and therefore may vary from one request to another. So, in case of query rewrite the allShards parameter should be used to get response from all available shards.

request.allShards(true); 

When the query is valid, the explanation defaults to the string representation of that query. With rewrite set to true, the explanation is more detailed showing the actual Lucene query that will be executed

request.rewrite(true); 

The asynchronous execution of a validate query request requires both the ValidateQueryRequest instance and an ActionListener instance to be passed to the asynchronous method:

client.indices().validateQueryAsync(request, RequestOptions.DEFAULT, listener); 

The asynchronous method does not block and returns immediately. Once it is completed the ActionListener is called back using the onResponse method if the execution successfully completed or using the onFailure method if it failed.

A typical listener for ValidateQueryResponse looks like:

ActionListener<ValidateQueryResponse> listener =
    new ActionListener<ValidateQueryResponse>() {
        @Override
        public void onResponse(ValidateQueryResponse validateQueryResponse) {
            
        }

        @Override
        public void onFailure(Exception e) {
            
        }
    };

The returned ValidateQueryResponse allows to retrieve information about the executed operation as follows:

boolean isValid = response.isValid(); 
int totalShards = response.getTotalShards(); 
int successfulShards = response.getSuccessfulShards(); 
int failedShards = response.getFailedShards(); 
if (failedShards > 0) {
    for(DefaultShardOperationFailedException failure: response.getShardFailures()) { 
        String failedIndex = failure.index(); 
        int shardId = failure.shardId(); 
        String reason = failure.reason(); 
    }
}
for(QueryExplanation explanation: response.getQueryExplanation()) { 
    String explanationIndex = explanation.getIndex(); 
    int shardId = explanation.getShard(); 
    String explanationString = explanation.getExplanation(); 
}