[EA3-78] chore : 공통 PageResponse 생성

Author: endorsement0912

src/main/java/grep/neogul_coder/global/response/PageResponse.java

@@ -0,0 +1,46 @@
+package grep.neogul_coder.global.response;
+
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.Page;
+
+@RequiredArgsConstructor
+public class PageResponse<T> {
+
+  private final String url;
+  private final Page<T> page;
+  private final int pageButtonCnt;
+
+  public String url(){
+    return url;
+  }
+
+  public int currentNumber(){
+    return page.getNumber() + 1;
+  }
+
+  public int prevPage(){
+    return Math.max(currentNumber() - 1, 1);
+  }
+
+  public int nextPage(){
+    return Math.min(currentNumber() + 1, calcTotalPage());
+  }
+
+  public int startNumber(){
+    return Math.floorDiv(page.getNumber(), pageButtonCnt) * pageButtonCnt + 1;
+  }
+
+  public int endNumber(){
+    return Math.min(startNumber() + pageButtonCnt - 1, calcTotalPage());
+  }
+
+  public List<T> content(){
+    return page.getContent();
+  }
+
+  private int calcTotalPage(){
+    int totalPage = page.getTotalPages();
+    return totalPage == 0 ? 1 : totalPage;
+  }
+}