getTargetType() {
+ return this.targetType;
+ }
+
+ protected String generateLimitCypherQuery() {
+ StringBuilder query = new StringBuilder();
+
+ query.append("START ").append(startStatement);
+ query.append(matchStatement != null ? " MATCH " + matchStatement : "");
+ query.append(whereStatement != null ? " WHERE " + whereStatement : "");
+ query.append(" RETURN ").append(returnStatement);
+ query.append(" ORDER BY ").append(orderByStatement);
+ query.append(" SKIP " + (pageSize * page));
+ query.append(" LIMIT " + pageSize);
+
+ String resultingQuery = query.toString();
+
+ if (logger.isDebugEnabled()) {
+ logger.debug(resultingQuery);
+ }
+
+ return resultingQuery;
+ }
+
+ /**
+ * Checks mandatory properties
+ *
+ * @see InitializingBean#afterPropertiesSet()
+ */
+ @Override
+ public void afterPropertiesSet() throws Exception {
+ Assert.state(template != null, "A Neo4JOperations implementation is required");
+ Assert.state(targetType != null, "The type to be returned is required");
+ Assert.state(StringUtils.hasText(startStatement), "A START statement is required");
+ Assert.state(StringUtils.hasText(returnStatement), "A RETURN statement is required");
+ Assert.state(StringUtils.hasText(orderByStatement), "A ORDER BY statement is required");
+ }
+}
diff --git a/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/data/Neo4jItemReader.java b/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/data/Neo4jItemReader.java
index 3f79bd501..305907265 100644
--- a/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/data/Neo4jItemReader.java
+++ b/spring-batch-infrastructure/src/main/java/org/springframework/batch/item/data/Neo4jItemReader.java
@@ -22,153 +22,32 @@ import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
-import org.springframework.batch.item.ItemReader;
-import org.springframework.beans.factory.InitializingBean;
+
import org.springframework.data.neo4j.conversion.DefaultConverter;
import org.springframework.data.neo4j.conversion.Result;
import org.springframework.data.neo4j.conversion.ResultConverter;
-import org.springframework.data.neo4j.template.Neo4jOperations;
-import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
-import org.springframework.util.StringUtils;
/**
*
- * Restartable {@link ItemReader} that reads objects from the graph database Neo4j
- * via a paging technique.
- *
- *
- *
- * It executes cypher queries built from the statement fragments provided to
- * retrieve the requested data. The query is executed using paged requests of
- * a size specified in {@link #setPageSize(int)}. Additional pages are requested
- * as needed when the {@link #read()} method is called. On restart, the reader
- * will begin again at the same number item it left off at.
- *
- *
- *
- * Performance is dependent on your Neo4J configuration (embedded or remote) as
- * well as page size. Setting a fairly large page size and using a commit
- * interval that matches the page size should provide better performance.
- *
- *
- *
- * This implementation is thread-safe between calls to
- * {@link #open(org.springframework.batch.item.ExecutionContext)}, however you
- * should set saveState=false if used in a multi-threaded
- * environment (no restart available).
+ * Extensions of the {@link AbstractNeo4jItemReader} intended for use with versions of
+ * Spring Data Neo4J < 4. Conversions of the results are done using an external
+ * {@link ResultConverter}.
*
*
* @author Michael Minella
- *
+ * @see org.springframework.batch.item.data.Neo4j4ItemReader
*/
-public class Neo4jItemReader extends AbstractPaginatedDataItemReader implements
-InitializingBean {
+public class Neo4jItemReader extends AbstractNeo4jItemReader {
protected Log logger = LogFactory.getLog(getClass());
- private Neo4jOperations template;
-
- private String startStatement;
- private String returnStatement;
- private String matchStatement;
- private String whereStatement;
- private String orderByStatement;
-
- private Class targetType;
-
- private Map parameterValues;
-
private ResultConverter, T> resultConverter;
public Neo4jItemReader() {
setName(ClassUtils.getShortName(Neo4jItemReader.class));
}
- /**
- * Optional parameters to be used in the cypher query.
- *
- * @param parameterValues the parameter values to be used in the cypher query
- */
- public void setParameterValues(Map parameterValues) {
- this.parameterValues = parameterValues;
- }
-
- /**
- * The start segment of the cypher query. START is prepended
- * to the statement provided and should not be
- * included.
- *
- * @param startStatement the start fragment of the cypher query.
- */
- public void setStartStatement(String startStatement) {
- this.startStatement = startStatement;
- }
-
- /**
- * The return statement of the cypher query. RETURN is prepended
- * to the statement provided and should not be
- * included
- *
- * @param returnStatement the return fragment of the cypher query.
- */
- public void setReturnStatement(String returnStatement) {
- this.returnStatement = returnStatement;
- }
-
- /**
- * An optional match fragment of the cypher query. MATCH is
- * prepended to the statement provided and should not
- * be included.
- *
- * @param matchStatement the match fragment of the cypher query
- */
- public void setMatchStatement(String matchStatement) {
- this.matchStatement = matchStatement;
- }
-
- /**
- * An optional where fragment of the cypher query. WHERE is
- * prepended to the statement provided and should not
- * be included.
- *
- * @param whereStatement where fragment of the cypher query
- */
- public void setWhereStatement(String whereStatement) {
- this.whereStatement = whereStatement;
- }
-
- /**
- * A list of properties to order the results by. This is
- * required so that subsequent page requests pull back the
- * segment of results correctly. ORDER BY is prepended to
- * the statement provided and should not be included.
- *
- * @param orderByStatement order by fragment of the cypher query.
- */
- public void setOrderByStatement(String orderByStatement) {
- this.orderByStatement = orderByStatement;
- }
-
- /**
- * Used to perform operations against the Neo4J database.
- *
- * @param template the Neo4jOperations instance to use
- * @see Neo4jOperations
- */
- public void setTemplate(Neo4jOperations template) {
- this.template = template;
- }
-
- /**
- * The object type to be returned from each call to {@link #read()}
- *
- * @param targetType the type of object to return.
- */
- public void setTargetType(Class targetType) {
- this.targetType = targetType;
- }
-
/**
* Set the converter used to convert node to the targetType. By
* default, {@link DefaultConverter} is used.
@@ -181,53 +60,19 @@ InitializingBean {
@Override
protected Iterator doPageRead() {
- Result> queryResults = template.query(
- generateLimitCypherQuery(), parameterValues);
+ Result> queryResults = getTemplate().query(
+ generateLimitCypherQuery(), getParameterValues());
if(queryResults != null) {
if (resultConverter != null) {
- return queryResults.to(targetType, resultConverter).iterator();
+ return queryResults.to(getTargetType(), resultConverter).iterator();
}
else {
- return queryResults.to(targetType).iterator();
+ return queryResults.to(getTargetType()).iterator();
}
}
else {
return new ArrayList().iterator();
}
}
-
- private String generateLimitCypherQuery() {
- StringBuilder query = new StringBuilder();
-
- query.append("START ").append(startStatement);
- query.append(matchStatement != null ? " MATCH " + matchStatement : "");
- query.append(whereStatement != null ? " WHERE " + whereStatement : "");
- query.append(" RETURN ").append(returnStatement);
- query.append(" ORDER BY ").append(orderByStatement);
- query.append(" SKIP " + (pageSize * page));
- query.append(" LIMIT " + pageSize);
-
- String resultingQuery = query.toString();
-
- if (logger.isDebugEnabled()) {
- logger.debug(resultingQuery);
- }
-
- return resultingQuery;
- }
-
- /**
- * Checks mandatory properties
- *
- * @see InitializingBean#afterPropertiesSet()
- */
- @Override
- public void afterPropertiesSet() throws Exception {
- Assert.state(template != null, "A Neo4JOperations implementation is required");
- Assert.state(targetType != null, "The type to be returned is required");
- Assert.state(StringUtils.hasText(startStatement), "A START statement is required");
- Assert.state(StringUtils.hasText(returnStatement), "A RETURN statement is required");
- Assert.state(StringUtils.hasText(orderByStatement), "A ORDER BY statement is required");
- }
}