因為業務的原因今天寫了一個原生的Spring Data jpa的分頁查詢 ：

1 .進行封裝自己PageQuery:

    public class PageQuery {

    public Integer getPage() {
        return page - 1;
    }

    public void setPage(Integer page) {
        this.page = page;
    }

    public Integer getSize() {
        return size;
    }

    public void
 
 setSize(Integer size) {
        this.size = size;
    }

    @NotNull(message = "引數不允許為空")
    private Integer page = 1; // 預設為1
    @NotNull(message = "引數不允許為空")
    private Integer size = 20;

}

1. 進行封裝 PageBean .

import java.util.List;
public class PageBean<T> {
    private Long totalCount; // 總記錄數
 

    private List<T> pageData; // 每頁記錄數
    public Long getTotalCount() {
        return totalCount;
    }
    public void setTotalCount(Long totalCount) {
        this.totalCount = totalCount;
    }
    public List<T> getPageData() {
        return pageData;
    }
    public void setPageData
 
(List<T> pageData) {
        this.pageData = pageData;
    }


}

1. 進行封裝自己的查詢引數：這個就不再多說了 。

2. SpingMVC controller

    //所有的終端與車輛關聯的資訊
    @RequestMapping("/vehicleAndTerminal.json")
    @ResponseBody
    public HashMap<String, Object> vehicleAndTerminal(PageQuery pageQuery, Terminal terminal){

        return  terminalService.vehicleAndTerminal(pageQuery, terminal);
    }

1. 進行業務層程式碼 ：
   5.1 注入entityManagerFactory

@Autowired
    private LocalContainerEntityManagerFactoryBean entityManagerFactory;

5.2 進行原生的Sql 拼接

// 此處用了原生的sql拼接
    // 有Sql注入的風險
    @Override
    public HashMap<String, Object> vehicleAndTerminal(PageQuery pageQuery, Terminal terminal) {
        HashMap<String, Object> map = new HashMap<String, Object>();
        String sql = "SELECT * FROM terminal t WHERE t.vSn IS NOT NULL AND t.vSn!=''";
        Integer page = pageQuery.getPage();
        Integer size = pageQuery.getSize();

        String vSn = terminal.getvSn();
        if (vSn != null) {
            sql += "AND t.vSn=" + vSn + " ";
        }
        String vin = terminal.getVin();
        if (vin != null) {
            sql += "AND t.vin=" + vin + " ";
        }
        String num = terminal.getNum();
        if (num != null) {
            sql += "AND t.num=" + num + " ";
        }
        String barcode = terminal.getBarcode();

        if (barcode != null) {
            sql += "AND t.barcode=" + barcode + " ";
        }
        sql += "LIMIT" + " " + page + "," + size;
        EntityManager em = entityManagerFactory.getNativeEntityManagerFactory().createEntityManager();
        Query nativeQuery = em.createNativeQuery(sql, Terminal.class);
        @SuppressWarnings({ "unused", "unchecked" })
        List<Terminal> termins = nativeQuery.getResultList();
        if (em != null) {
            em.close();
        }
        map.put("total", termins.size());
        map.put("rows", termins);
        return map;
    }

這樣就實現了動態查詢 ，以及分頁。 上面的程式碼 我自己封裝的PageBean 沒有用上 ，下面的程式碼是改過的

public PageBean<Terminal> vehicleAndTerminal(PageQuery pageQuery, Terminal terminal) {
        HashMap<String, Object> map = new HashMap<String, Object>();
        String sql = "SELECT * FROM terminal t WHERE t.vSn IS NOT NULL AND t.vSn!=''";
        Integer page = pageQuery.getPage();
        Integer size = pageQuery.getSize();

        String vSn = terminal.getvSn();
        if (vSn != null) {
            sql += "AND t.vSn=" + vSn + " ";
        }
        String vin = terminal.getVin();
        if (vin != null) {
            sql += "AND t.vin=" + vin + " ";
        }
        String num = terminal.getNum();
        if (num != null) {
            sql += "AND t.num=" + num + " ";
        }
        String barcode = terminal.getBarcode();

        if (barcode != null) {
            sql += "AND t.barcode=" + barcode + " ";
        }
        sql += "LIMIT" + " " + page + "," + size;
        EntityManager em = entityManagerFactory.getNativeEntityManagerFactory().createEntityManager();
        Query nativeQuery = em.createNativeQuery(sql, Terminal.class);
        @SuppressWarnings({ "unused", "unchecked" })
        List<Terminal> termins = nativeQuery.getResultList();
        if (em != null) {
            em.close();
        }
        // map.put("total", termins.size());
        // map.put("rows", termins);
        // return map;

        PageBean<Terminal> pageBean = new PageBean<>();

        pageBean.setTotalCount((long) termins.size());

        pageBean.setPageData(termins);

        return pageBean;
    }