Use SOLR SPECICIC Commons CSV to develop Java libraries
Use SOLR SPECICIC Commons CSV to develop Java libraries
Apache Solr is a powerful full -text search platform that provides rich search functions and scalability.SOLR Specific Commons CSV is a functional library of solr to process CSV files.In this article, we will explore how to use the SOLR Specific Commons CSV for Java library development.
First of all, we need to import the dependencies of SOLR Specific Commons CSV in the Java project.It can be achieved by adding the following dependencies to the pom.xml file of the project:
<dependency>
<groupId>org.apache.solr</groupId>
<artifactId>solr-core</artifactId>
<version>8.6.3</version>
</dependency>
Next, we need to create a Java class and write code in the class to process CSV files.The following is a basic example:
import org.apache.solr.common.SolrInputDocument;
import org.apache.solr.common.SolrException;
import org.apache.solr.common.SolrInputField;
import org.apache.solr.common.util.ContentStreamBase;
import org.apache.solr.common.util.ContentStreamBase.ByteArrayStream;
import org.apache.solr.handler.loader.CSVLoader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
public class SolrCSVHandler {
private SolrInputDocument processCSV(InputStream inputStream) throws IOException {
CSVLoader csvLoader = new CSVLoader();
List<SolrInputField> fields = new ArrayList<>();
// Determine the separator and field name
char delimiter = ',';
String[] fieldNames = {"id", "name", "description"};
csvLoader.load(SolrCSVHandler::processRow, delimiter, fieldNames, fields, inputStream);
SolrInputDocument document = new SolrInputDocument();
fields.forEach(field -> document.addField(field.getName(), field.getValue()));
return document;
}
private static boolean processRow(int row, CSVLoader.RowData rowData, List<SolrInputField> fields) {
boolean success = true;
if (row == 0) {
// Skip the title line
return success;
}
try {
SolrInputField field = new SolrInputField(rowData.getFieldName(), rowData.getUtf8StringValue());
fields.add(field);
} catch (SolrException e) {
success = false;
}
return success;
}
private InputStream convertToInputStream(String csvData) {
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
outputStream.write(csvData.getBytes(StandardCharsets.UTF_8));
return new ByteArrayStream(outputStream.toByteArray(), null);
}
public static void main(String[] args) throws IOException {
String csvData = "1,Apple,A fruit
2,Orange,Another fruit";
SolrCSVHandler csvHandler = new SolrCSVHandler();
InputStream inputStream = csvHandler.convertToInputStream(csvData);
SolrInputDocument document = csvHandler.processCSV(inputStream);
System.out.println(document.toString());
}
}
In the above code, we create a Solrcsvhandler class that contains logic of processing CSV files.The main method is the `ProcessCSV` method. It receives an input stream as a parameter and creates a solrinputdocume object based on the content of the CSV file.In this method, we use the csvloader.load method to handle each line of the CSV file.In the `processRow` method, we can customize the data of each line.In this example, we just store the names and corresponding values of each field into a list, and eventually add them to SolrinputDocument.
In the `Main` method, we created a sample CSV data and converted it into an input stream.We then call the `ProcessCSV` method to process CSV data and print the -generated SolrinputDocument object.
We can also configure some configurations when using SOLR Specific Commons CSV for Java libraries.For example, you can adapt to different CSV files by changing division partitions and definition field names.
In summary, this article introduces how to use solr Specific Commons CSV for Java library development.We understand how to import dependencies, write code for processing CSV files, and explain related configuration options.Hope this article can help you use the Solr Specific Commons CSV library when developing a Java application.
