From 7eea5ed7e09a7c1a45963bf19b4a9afbef2de85e Mon Sep 17 00:00:00 2001
From: ZhouXY108 <luquanlion@outlook.com>
Date: Tue, 8 Nov 2022 13:52:44 +0800
Subject: [PATCH] =?UTF-8?q?=E5=B0=86=20PageDTO=20=E5=92=8C=20PagingAndSort?=
 =?UTF-8?q?ingQueryParams=20=E6=B7=BB=E5=8A=A0=E5=88=B0=20plusone-commons?=
 =?UTF-8?q?=E3=80=82?=
MIME-Version: 1.0
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Content-Transfer-Encoding: 8bit

---
 .../java/xyz/zhouxy/plusone/util/PageDTO.java | 40 ++++++++++++++
 .../util/PagingAndSortingQueryParams.java     | 53 +++++++++++++++++++
 2 files changed, 93 insertions(+)
 create mode 100644 src/main/java/xyz/zhouxy/plusone/util/PageDTO.java
 create mode 100644 src/main/java/xyz/zhouxy/plusone/util/PagingAndSortingQueryParams.java

diff --git a/src/main/java/xyz/zhouxy/plusone/util/PageDTO.java b/src/main/java/xyz/zhouxy/plusone/util/PageDTO.java
new file mode 100644
index 0000000..dce9bc8
--- /dev/null
+++ b/src/main/java/xyz/zhouxy/plusone/util/PageDTO.java
@@ -0,0 +1,40 @@
+package xyz.zhouxy.plusone.util;
+
+import java.util.List;
+
+import lombok.Setter;
+import lombok.ToString;
+
+/**
+ * 返回分页查询的结果
+ *
+ * @param <T> 内容列表的元素类型
+ *
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @see PagingAndSortingQueryParams
+ */
+@ToString
+@Setter
+public class PageDTO<T> {
+
+    private Long total;
+    private List<T> content;
+
+    private PageDTO(List<T> content, Long total) {
+        this.content = content;
+        this.total = total;
+    }
+
+    public static <T> PageDTO<T> of(List<T> content, Long total) {
+        return new PageDTO<>(content, total);
+    }
+
+    public Long getTotal() {
+        return total;
+    }
+
+    public List<T> getContent() {
+        return content;
+    }
+
+}
diff --git a/src/main/java/xyz/zhouxy/plusone/util/PagingAndSortingQueryParams.java b/src/main/java/xyz/zhouxy/plusone/util/PagingAndSortingQueryParams.java
new file mode 100644
index 0000000..78b2ddf
--- /dev/null
+++ b/src/main/java/xyz/zhouxy/plusone/util/PagingAndSortingQueryParams.java
@@ -0,0 +1,53 @@
+package xyz.zhouxy.plusone.util;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import lombok.Setter;
+
+/**
+ * 分页排序查询参数
+ *
+ * <p>
+ * 根据传入的 {@code size} 和 {@code pageNum}，
+ * 提供 {@code getOffset} 方法计算 SQL 语句中 {@code offset} 的值。
+ * </p>
+ *
+ * @author <a href="https://gitee.com/zhouxy108">ZhouXY</a>
+ * @see PageDTO
+ */
+@Setter
+public class PagingAndSortingQueryParams {
+
+    protected String orderBy;
+    protected Integer size;
+    protected Long pageNum;
+
+    private final List<String> sortableColNames;
+
+    public PagingAndSortingQueryParams() {
+        sortableColNames = Collections.emptyList();
+    }
+
+    public PagingAndSortingQueryParams(String... sortableColNames) {
+        this.sortableColNames = Arrays.asList(sortableColNames);
+    }
+
+    public String getOrderBy() {
+        return orderBy != null && sortableColNames.contains(orderBy) ? orderBy : null;
+    }
+
+    public int getSize() {
+        return this.size != null ? this.size : 15;
+    }
+
+    public long getPageNum() {
+        return this.pageNum != null ? this.pageNum : 1;
+    }
+
+    public long getOffset() {
+        return (getPageNum() - 1) * getSize();
+    }
+
+}