fixes #1257: apoc.load.json file roundtrip from apoc.export.json.all

docs/asciidoc/import/loadjson.adoc

@@ -195,3 +195,28 @@ You will receive the following response:
   "weight": 0.02548018842935562
 }
 ----
+
+== Import JSON
+
+If you used the `apoc.export.json.all` to export the graph, we provide the `apoc.import.json` to reimport that data.
+
+[source,cypher]
+----
+CALL apoc.import.json($file, $config)
+----
+
+The `$config` parameter is a map
+
+[opts=header,cols="m,m"]
+|===
+| name | default | description
+| unwindBatchSize | 5000 | the batch size of the unwind
+| txBatchSize | 5000 | the batch size of the transacttion
+| importIdName | neo4jImportId | the name of the "id" field into the used for the import it refers to the "id" field into the root object of the json.
+| nodePropertyMappings | {} | The mapping label/property name/property type for Custom Neo4j types (point date). I.e. { User: { born: 'Point', dateOfBirth: 'Datetime' } }
+| relPropertyMappings | {} | The mapping rel type/property name/property type for Custom Neo4j types (point date). I.e. { KNOWS: { since: 'Datetime' } }
+|===
+
+N.b. Supported Neo4j types via config mappings are:
+
+Point, Localdate, Localtime, Localdatetime, Duration, offsettime, Zoneddatetime

src/main/java/apoc/export/json/ImportJson.java

@@ -0,0 +1,45 @@
+package apoc.export.json;
+
+import apoc.export.util.CountingReader;
+import apoc.export.util.ProgressReporter;
+import apoc.result.ProgressInfo;
+import apoc.util.FileUtils;
+import apoc.util.JsonUtil;
+import apoc.util.Util;
+import org.neo4j.graphdb.GraphDatabaseService;
+import org.neo4j.procedure.Context;
+import org.neo4j.procedure.Description;
+import org.neo4j.procedure.Mode;
+import org.neo4j.procedure.Name;
+import org.neo4j.procedure.Procedure;
+
+import java.util.Map;
+import java.util.Scanner;
+import java.util.stream.Stream;
+
+public class ImportJson {
+    @Context
+    public GraphDatabaseService db;
+
+    @Procedure(value = "apoc.import.json", mode = Mode.WRITE)
+    @Description("apoc.import.json(file,config) - imports the json list to the provided file")
+    public Stream<ProgressInfo> all(@Name("file") String fileName, @Name(value = "config", defaultValue = "{}") Map<String, Object> config) {
+        ProgressInfo result =
+                Util.inThread(() -> {
+                    ImportJsonConfig importJsonConfig = new ImportJsonConfig(config);
+                    ProgressReporter reporter = new ProgressReporter(null, null, new ProgressInfo(fileName, "file", "json"));
+
+                    try (final CountingReader reader = FileUtils.readerFor(fileName);
+                         final Scanner scanner = new Scanner(reader).useDelimiter("\n|\r");
+                         JsonImporter jsonImporter = new JsonImporter(importJsonConfig, db, reporter)) {
+                        while (scanner.hasNext()) {
+                            Map<String, Object> row = JsonUtil.OBJECT_MAPPER.readValue(scanner.nextLine(), Map.class);
+                            jsonImporter.importRow(row);
+                        }
+                    }
+
+                    return reporter.getTotal();
+                });
+        return Stream.of(result);
+    }
+}

src/main/java/apoc/export/json/ImportJsonConfig.java

@@ -0,0 +1,52 @@
+package apoc.export.json;
+
+import apoc.util.Util;
+import org.apache.commons.lang3.StringUtils;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Map;
+
+public class ImportJsonConfig {
+
+    private final Map<String, Map<String, String>> nodePropertyMappings;
+    private final Map<String, Map<String, String>> relPropertyMappings;
+
+    private final int unwindBatchSize;
+    private final int txBatchSize;
+
+    private final String importIdName;
+
+    public ImportJsonConfig(Map<String, Object> config) {
+        config = config == null ? Collections.emptyMap() : config;
+        this.nodePropertyMappings = (Map<String, Map<String, String>>) config.getOrDefault("nodePropertyMappings", Collections.emptyMap());
+        this.relPropertyMappings = (Map<String, Map<String, String>>) config.getOrDefault("relPropertyMappings", Collections.emptyMap());
+        this.unwindBatchSize = Util.toInteger(config.getOrDefault("unwindBatchSize", 5000));
+        this.txBatchSize = Util.toInteger(config.getOrDefault("txBatchSize", 5000));
+        this.importIdName = (String) config.getOrDefault("importIdName", "neo4jImportId");
+    }
+
+    public String typeForNode(Collection<String> labels, String property) {
+        return labels.stream()
+                .map(label -> nodePropertyMappings.getOrDefault(label, Collections.emptyMap()).get(property))
+                .filter(StringUtils::isNotBlank)
+                .findFirst()
+                .orElse(null);
+    }
+
+    public String typeForRel(String type, String property) {
+        return relPropertyMappings.getOrDefault(type, Collections.emptyMap()).get(property);
+    }
+
+    public int getUnwindBatchSize() {
+        return unwindBatchSize;
+    }
+
+    public int getTxBatchSize() {
+        return txBatchSize;
+    }
+
+    public String getImportIdName() {
+        return importIdName;
+    }
+}