我是Elasticsearch的新手并且想知道如何使用NEST C＃将关于json文档的索引和索引创建到Elasticsearch？
{
"BookName": "Book1",
"ISBN": "978-3-16-148410-0",
"chapter" : [
{
"chapter_name": "Chapter1",
"chapter_desc": "Before getting into computer programming, let us first understand computer programs and what they..."
},
{
"chapter_name": "Chapter2",
"chapter_desc": "Today computer programs are being used in almost every field, household, agriculture, medical, entertainment, defense.."
},
{
"chapter_name": "Chapter3",
"chapter_desc": "MS Word, MS Excel, Adobe Photoshop, Internet Explorer, Chrome, etc., are..."
},
{
"chapter_name": "Chapter4",
"chapter_desc": "Computer programs are being used to develop graphics and special effects in movie..."
}
]
}
答案 0 :(得分：5)
使用NEST创建索引就像
一样简单import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableModel;
import javax.swing.table.TableRowSorter;
/**
* @see https://stackoverflow.com/a/37913520/230513
* @see https://stackoverflow.com/a/37892395/230513
*/
public class JTableColumnTotalExample {
public static void main(String[] args) {
EventQueue.invokeLater(JTableColumnTotalExample::display);
}
public static void display() {
JFrame f = new JFrame("JTable Sorting Example");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
List<Employee> listEmployees = createListEmployees();
TableModel model = new EmployeeTableModel(listEmployees);
JTable table = new JTable(model) {
@Override
public Dimension getPreferredScrollableViewportSize() {
return new Dimension(500, getRowCount() * getRowHeight());
}
};
table.getColumnModel().getColumn(3).setCellRenderer(new CurrencyFormatter());
TableRowSorter sorter = new TableRowSorter<TableModel>(model) {
@Override
public int convertRowIndexToModel(int index) {
int maxRow = super.getViewRowCount();
if (index >= maxRow) {
return index;
}
return super.convertRowIndexToModel(index);
}
@Override
public int convertRowIndexToView(int index) {
int maxRow = super.getModelRowCount();
if (index > maxRow) {
return index;
}
return super.convertRowIndexToView(index);
}
@Override
public int getViewRowCount() {
return super.getViewRowCount() + 1;
}
};
table.setRowSorter(sorter);
f.add(new JScrollPane(table), BorderLayout.CENTER);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
private static List<Employee> createListEmployees() {
List<Employee> listEmployees = new ArrayList<>();
listEmployees.add(new Employee("Peter", "Manager", 40000));
listEmployees.add(new Employee("Paul", "Programmer", 25000));
listEmployees.add(new Employee("Mary", "Designer", 25000));
listEmployees.add(new Employee("Donald", "Leader", 30000));
listEmployees.add(new Employee("Tom", "Designer", 28000));
listEmployees.add(new Employee("Samantha", "Analyst", 50000));
listEmployees.add(new Employee("Jerome", "Programmer", 32000));
listEmployees.add(new Employee("Jonathon", "Developer", 29000));
listEmployees.add(new Employee("Kevin", "Programmer", 23000));
listEmployees.add(new Employee("Anthony", "Programmer", 23000));
listEmployees.add(new Employee("John", "Designer", 33000));
listEmployees.add(new Employee("David", "Developer", 28000));
listEmployees.add(new Employee("Harry", "Designer", 31000));
listEmployees.add(new Employee("Charles", "Programmer", 26000));
listEmployees.add(new Employee("Joseph", "Manager", 40000));
return listEmployees;
}
private static class EmployeeTableModel extends AbstractTableModel {
private static final int COLUMN_NUM = 0;
private static final int COLUMN_NAME = 1;
private static final int COLUMN_JOB = 2;
private static final int COLUMN_SALARY = 3;
private final String[] columnNames = {"No", "Name", "Job", "Salary"};
private final List<Employee> listEmployees;
public EmployeeTableModel(List<Employee> listEmployees) {
this.listEmployees = listEmployees;
int indexCount = 1;
for (Employee employee : listEmployees) {
employee.setIndex(indexCount++);
}
}
@Override
public int getColumnCount() {
return columnNames.length;
}
@Override
public int getRowCount() {
return listEmployees.size();
}
@Override
public String getColumnName(int columnIndex) {
return columnNames[columnIndex];
}
@Override
public Class<?> getColumnClass(int columnIndex) {
return getValueAt(0, columnIndex).getClass();
}
@Override
public Object getValueAt(int rowIndex, int columnIndex) {
if (rowIndex == getRowCount()) {
switch (columnIndex) {
case COLUMN_NUM:
return 999_999_999;
case COLUMN_NAME:
return "Total";
case COLUMN_JOB:
return "Salary";
case COLUMN_SALARY:
return sum();
}
}
Employee employee = listEmployees.get(rowIndex);
switch (columnIndex) {
case COLUMN_NUM:
return employee.getIndex();
case COLUMN_NAME:
return employee.getName();
case COLUMN_JOB:
return employee.getJob();
case COLUMN_SALARY:
return employee.getSalary();
default:
throw new IllegalArgumentException("Invalid column index");
}
}
private int sum() {
int sum = 0;
for (int r = 0; r < getRowCount(); r++) {
sum += (int) getValueAt(r, COLUMN_SALARY);
}
return sum;
}
}
private static class Employee {
private int index;
private String name;
private String job;
private int salary;
public Employee(String name, String job, int salary) {
this.name = name;
this.job = job;
this.salary = salary;
}
public int getIndex() {
return index;
}
public void setIndex(int index) {
this.index = index;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getJob() {
return job;
}
public void setJob(String job) {
this.job = job;
}
public int getSalary() {
return salary;
}
public void setSalary(int age) {
this.salary = age;
}
}
private static class CurrencyFormatter extends DefaultTableCellRenderer {
private NumberFormat numberFormat = NumberFormat.getCurrencyInstance();
@Override
public Component getTableCellRendererComponent(JTable jTable, Object value,
boolean isSelected, boolean hasFocus, int row, int column) {
Component c = super.getTableCellRendererComponent(jTable, value,
isSelected, hasFocus, row, column);
if (c instanceof JLabel && value instanceof Number) {
JLabel label = (JLabel) c;
label.setHorizontalAlignment(JLabel.RIGHT);
Number num = (Number) value;
String text = numberFormat.format(num);
label.setText(text);
}
return c;
}
}
}
这将创建一个索引，其中包含为节点定义的默认分片数和副本数。
将表示为json的文档索引到索引中
var client = new ElasticClient();
client.CreateIndex("index-name");
这里我们使用低级客户端索引json，通过var json = @"{
""BookName"": ""Book1"",
""ISBN"": ""978-3-16-148410-0"",
""chapter"" : [
{
""chapter_name"": ""Chapter1"",
""chapter_desc"": ""Before getting into computer programming, let us first understand computer programs and what they...""
},
{
""chapter_name"": ""Chapter2"",
""chapter_desc"": ""Today computer programs are being used in almost every field, household, agriculture, medical, entertainment, defense..""
},
{
""chapter_name"": ""Chapter3"",
""chapter_desc"": ""MS Word, MS Excel, Adobe Photoshop, Internet Explorer, Chrome, etc., are...""
},
{
""chapter_name"": ""Chapter4"",
""chapter_desc"": ""Computer programs are being used to develop graphics and special effects in movie...""
}
]
}";
var indexResponse = client.LowLevel.Index<string>("index-name", "type-name", json);
if (!indexResponse.Success)
Console.WriteLine(indexResponse.DebugInformation);
上的.LowLevel属性在NEST中提供。
要搜索索引文档
ElasticClient这将返回索引的文档。此处// refresh the index so that newly indexed documents are available
// for search without waiting for the refresh interval
client.Refresh("index-name");
var searchResponse = client.Search<dynamic>(s => s
.Index("index-name")
.Type("type-name")
.Query(q => q
.Match(m => m
.Query("Photoshop")
.Field("chapter.chapter_desc")
)
)
);
中使用的泛型类型参数dynamic表示生成的文档将被反序列化为Json.Net Search<T>()类型。
当我们创建索引时，我们没有为我们的类型JObject指定映射，因此Elasticsearch从json文档的结构推断出映射。 This is dynamic mapping并且在许多情况下都很有用，但是，如果您知道要发送的文档的结构并且不会破坏性地更改，那么您specify a mapping for the type。在这个特定示例中执行此操作的优点是type-name数组将被推断为object type映射，但如果您要搜索单个章节的章节名称和章节描述，那么您可能希望将chapter映射为nested type。