package club.datatables.serverside.javaversion;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.jpa.datatables.repository.DataTablesRepositoryFactoryBean;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

/**
 * @author Datatables中文网 http://datatables.club
 * @date 2020年09月08日14:37:27
 */
@SpringBootApplication
@EnableJpaRepositories(repositoryFactoryBeanClass = DataTablesRepositoryFactoryBean.class)
public class JavaversionApplication {

    public static void main(String[] args) {
        SpringApplication.run(JavaversionApplication.class, args);
    }

}

package club.datatables.serverside.javaversion.entity;


import lombok.Data;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import java.sql.Timestamp;

/**
 * @author Datatables中文网 http://datatables.club
 * @date 2020年09月08日14:37:27
 *
 * 实体类
 */
@Entity
@Table(name = "tb_datatables_demo")
@Data
public class DatatablesDemo {
    @Id
    private Long id;
    private String firstName;
    private String lastName;
    private String position;
    private String email;
    private String office;
    private Timestamp startDate;
    private Integer age;
    private Integer salary;
    private Integer seq;
    private String extn;
}

package club.datatables.serverside.javaversion.dao;

import club.datatables.serverside.javaversion.entity.DatatablesDemo;
import org.springframework.data.jpa.datatables.repository.DataTablesRepository;
import org.springframework.data.jpa.repository.JpaRepository;


/**
 * @author Datatables中文网 http://datatables.club
 * @date 2020年09月08日14:37:27
 *
 * 持久层
 */
public interface DatatablesDemoRepository
        extends DataTablesRepository<DatatablesDemo,Long>, JpaRepository<DatatablesDemo,Long> {

}

package club.datatables.serverside.javaversion.controller;

import club.datatables.serverside.javaversion.dao.DatatablesDemoRepository;
import club.datatables.serverside.javaversion.entity.DatatablesDemo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.jpa.datatables.mapping.DataTablesInput;
import org.springframework.data.jpa.datatables.mapping.DataTablesOutput;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import javax.validation.Valid;
import java.util.*;


/**
 * @author Datatables中文网 http://datatables.club
 * @date 2020年09月08日14:37:27
 *
 * 控制器
 */
@Controller
public class DatatablesDemoController {

    @Autowired
    DatatablesDemoRepository empRepository;

    /**
     * 服务端模式
     * @param input
     * @return
     */
    @RequestMapping(value = "/dtlist", method = RequestMethod.GET)
    @ResponseBody
    public DataTablesOutput<DatatablesDemo> list(@Valid DataTablesInput input) {
        return empRepository.findAll(input);
    }

}

package org.springframework.data.jpa.datatables.mapping;

import lombok.Data;

import javax.validation.constraints.Min;
import javax.validation.constraints.NotEmpty;
import javax.validation.constraints.NotNull;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Data
public class DataTablesInput {

  /**
   * Draw counter. This is used by DataTables to ensure that the Ajax returns from server-side
   * processing requests are drawn in sequence by DataTables (Ajax requests are asynchronous and
   * thus can return out of sequence). This is used as part of the draw return parameter (see
   * below).
   */
  @NotNull
  @Min(0)
  private Integer draw = 1;

  /**
   * Paging first record indicator. This is the start point in the current data set (0 index based -
   * i.e. 0 is the first record).
   */
  @NotNull
  @Min(0)
  private Integer start = 0;

  /**
   * Number of records that the table can display in the current draw. It is expected that the
   * number of records returned will be equal to this number, unless the server has fewer records to
   * return. Note that this can be -1 to indicate that all records should be returned (although that
   * negates any benefits of server-side processing!)
   */
  @NotNull
  @Min(-1)
  private Integer length = 10;

  /**
   * Global search parameter.
   */
  @NotNull
  private Search search = new Search();

  /**
   * Order parameter
   */
  @NotEmpty
  private List<Order> order = new ArrayList<>();

  /**
   * Per-column search parameter
   */
  @NotEmpty
  private List<Column> columns = new ArrayList<>();

  /**
   * 
   * @return a {@link Map} of {@link Column} indexed by name
   */
  public Map<String, Column> getColumnsAsMap() {
    Map<String, Column> map = new HashMap<>();
    for (Column column : columns) {
      map.put(column.getData(), column);
    }
    return map;
  }

  /**
   * Find a column by its name
   *
   * @param columnName the name of the column
   * @return the given Column, or <code>null</code> if not found
   */
  public Column getColumn(String columnName) {
    if (columnName == null) {
      return null;
    }
    for (Column column : columns) {
      if (columnName.equals(column.getData())) {
        return column;
      }
    }
    return null;
  }

  /**
   * Add a new column
   *
   * @param columnName the name of the column
   * @param searchable whether the column is searchable or not
   * @param orderable whether the column is orderable or not
   * @param searchValue if any, the search value to apply
   */
  public void addColumn(String columnName, boolean searchable, boolean orderable,
      String searchValue) {
    this.columns.add(new Column(columnName, "", searchable, orderable,
        new Search(searchValue, false)));
  }

  /**
   * Add an order on the given column
   *
   * @param columnName the name of the column
   * @param ascending whether the sorting is ascending or descending
   */
  public void addOrder(String columnName, boolean ascending) {
    if (columnName == null) {
      return;
    }
    for (int i = 0; i < columns.size(); i++) {
      if (!columnName.equals(columns.get(i).getData())) {
        continue;
      }
      order.add(new Order(i, ascending ? "asc" : "desc"));
    }
  }

}

package org.springframework.data.jpa.datatables.mapping;

import com.fasterxml.jackson.annotation.JsonView;
import lombok.Data;

import java.util.Collections;
import java.util.List;

@Data
public class DataTablesOutput<T> {

  /**
   * The draw counter that this object is a response to - from the draw parameter sent as part of
   * the data request. Note that it is strongly recommended for security reasons that you cast this
   * parameter to an integer, rather than simply echoing back to the client what it sent in the draw
   * parameter, in order to prevent Cross Site Scripting (XSS) attacks.
   */
  @JsonView(View.class)
  private int draw;

  /**
   * Total records, before filtering (i.e. the total number of records in the database)
   */
  @JsonView(View.class)
  private long recordsTotal = 0L;

  /**
   * Total records, after filtering (i.e. the total number of records after filtering has been
   * applied - not just the number of records being returned for this page of data).
   */
  @JsonView(View.class)
  private long recordsFiltered = 0L;

  /**
   * The data to be displayed in the table. This is an array of data source objects, one for each
   * row, which will be used by DataTables. Note that this parameter's name can be changed using the
   * ajaxDT option's dataSrc property.
   */
  @JsonView(View.class)
  private List<T> data = Collections.emptyList();

  /**
   * Optional: If an error occurs during the running of the server-side processing script, you can
   * inform the user of this error by passing back the error message to be displayed using this
   * parameter. Do not include if there is no error.
   */
  @JsonView(View.class)
  private String error;

  public interface View {
  }

}