update demo

README.md

@@ -39,4 +39,10 @@
   "data": "小奏",
   "msg": "success"
 }
-```
+```
+
+### 提供开箱即用的分页对象
+- [NebulaPage.java](spring-boot-nebula-web%2Fsrc%2Fmain%2Fjava%2Fcom%2Fnebula%2Fweb%2Fboot%2Fapi%2FNebulaPage.java)
+- [NebulaPageQuery.java](spring-boot-nebula-web%2Fsrc%2Fmain%2Fjava%2Fcom%2Fnebula%2Fweb%2Fboot%2Fapi%2FNebulaPageQuery.java)
+
+使用

spring-boot-nebula-web/src/main/java/com/nebula/web/boot/api/NebulaPage.java

@@ -0,0 +1,95 @@
+package com.nebula.web.boot.api;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+/**
+ * @author : wh
+ * @date : 2023/8/16 10:02
+ * @description: 基础分页对象
+ */
+public class NebulaPage<T> {
+
+    private long totalCount = 0;
+
+    private int pageSize = 1;
+
+    private Collection<T> list;
+
+    public long getTotalCount() {
+        return totalCount;
+    }
+
+    public void setTotalCount(long totalCount) {
+        this.totalCount = totalCount;
+    }
+
+    public int getPageSize() {
+        if (pageSize < 1) {
+            return 1;
+        }
+        return pageSize;
+    }
+
+    public void setPageSize(int pageSize) {
+        if (pageSize < 1) {
+            this.pageSize = 1;
+        } else {
+            this.pageSize = pageSize;
+        }
+    }
+
+    public Collection<T> getList() {
+        return list;
+    }
+
+    public void setList(Collection<T> list) {
+        this.list = list;
+    }
+
+    /**
+     * 构造器
+     *
+     * @param list
+     * @param total
+     * @param pageSize
+     * @param <T>
+     * @return
+     */
+    public static <T> NebulaPage<T> of(Collection<T> list, long total, int pageSize) {
+        NebulaPage<T> page = new NebulaPage<>();
+        page.setList(list);
+        page.setTotalCount(total);
+        page.setPageSize(pageSize);
+        return page;
+    }
+
+    /**
+     * 内存分页
+     *
+     * @param list
+     * @param pageQuery
+     * @param <T>
+     * @return
+     */
+    public static <T> NebulaPage<T> ofMemory(Collection<T> list, NebulaPageQuery pageQuery) {
+        List<T> pageList = list.stream().skip((long) (pageQuery.getPageIndex() - 1) * pageQuery.getPageSize())
+            .limit(pageQuery.getPageSize()).collect(Collectors.toList());
+        NebulaPage<T> page = new NebulaPage<>();
+        page.setList(pageList);
+        page.setTotalCount(list.size());
+        page.setPageSize(pageQuery.getPageSize());
+        return page;
+    }
+
+    public static <T, R> NebulaPage<R> copy(NebulaPage<T> source, Function<T, R> converterFunction) {
+        NebulaPage<R> Page = new NebulaPage<>();
+        Page.setList(source.getList().stream().map(converterFunction).collect(Collectors.toList()));
+        Page.setTotalCount(source.getTotalCount());
+        Page.setPageSize(source.getPageSize());
+        return Page;
+    }
+
+}

spring-boot-nebula-web/src/main/java/com/nebula/web/boot/api/NebulaPageQuery.java

@@ -0,0 +1,90 @@
+package com.nebula.web.boot.api;
+
+/**
+ * @author : wh
+ * @date : 2023/8/16 10:04
+ * @description:
+ */
+public abstract class NebulaPageQuery {
+
+    public static final String ASC = "ASC";
+
+    public static final String DESC = "DESC";
+
+    private static final int DEFAULT_PAGE_SIZE = 20;
+
+    private Integer pageSize = DEFAULT_PAGE_SIZE;
+
+    private Integer pageIndex = 1;
+
+    private String orderBy;
+
+    private String orderDirection = DESC;
+
+    private String groupBy;
+
+    private boolean needTotalCount = true;
+
+    public int getPageIndex() {
+        if (pageIndex < 1) {
+            return 1;
+        }
+        return pageIndex;
+    }
+
+    public void setPageIndex(int pageIndex) {
+        this.pageIndex = pageIndex;
+    }
+
+    public int getPageSize() {
+        if (pageSize < 1) {
+            pageSize = DEFAULT_PAGE_SIZE;
+        }
+        return pageSize;
+    }
+
+    public void setPageSize(int pageSize) {
+        if (pageSize < 1) {
+            pageSize = DEFAULT_PAGE_SIZE;
+        }
+        this.pageSize = pageSize;
+    }
+
+    public int getOffset() {
+        return (getPageIndex() - 1) * getPageSize();
+    }
+
+    public String getOrderBy() {
+        return orderBy;
+    }
+
+    public void setOrderBy(String orderBy) {
+        this.orderBy = orderBy;
+    }
+
+    public String getOrderDirection() {
+        return orderDirection;
+    }
+
+    public void setOrderDirection(String orderDirection) {
+        if (ASC.equalsIgnoreCase(orderDirection) || DESC.equalsIgnoreCase(orderDirection)) {
+            this.orderDirection = orderDirection;
+        }
+    }
+
+    public String getGroupBy() {
+        return groupBy;
+    }
+
+    public void setGroupBy(String groupBy) {
+        this.groupBy = groupBy;
+    }
+
+    public boolean isNeedTotalCount() {
+        return needTotalCount;
+    }
+
+    public void setNeedTotalCount(boolean needTotalCount) {
+        this.needTotalCount = needTotalCount;
+    }
+}