【优化】分页

This commit is contained in:
MichaelWin
2026-01-28 09:22:46 +08:00
parent de8f44f063
commit 7d51a13dd7
2 changed files with 133 additions and 12 deletions

View File

@@ -1,23 +1,134 @@
package com.corewing.app.common.page;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import java.util.HashMap;
import java.util.Map;
public class PageContext {
private static final ThreadLocal<Page<?>> PAGE_HOLDER = new ThreadLocal<>();
private static final ThreadLocal<PagePool> PAGE_POOL_HOLDER = new ThreadLocal<>();
// 设置分页对象
public static void setPage(Page<?> page) {
PAGE_HOLDER.set(page);
private static class PagePool {
private final Map<String, Page<?>> pool = new HashMap<>();
private int counter = 0;
public synchronized String generateKey() {
return "page_" + (counter++);
}
public Page<?> get(String key) {
return pool.get(key);
}
public void put(String key, Page<?> page) {
pool.put(key, page);
}
public void remove(String key) {
pool.remove(key);
}
public void clear() {
pool.clear();
counter = 0;
}
public boolean isEmpty() {
return pool.isEmpty();
}
}
// 泛型方法:获取指定类型的分页对象(消除警告)
@SuppressWarnings("unchecked")
/**
* 获取一个新的 Page 对象带唯一key
* 适合单个查询场景
*/
public static <T> Page<T> getPage(Class<T> clazz) {
return (Page<T>) PAGE_HOLDER.get();
PagePool pool = getPagePool();
String key = pool.generateKey();
Page<T> page = new Page<>();
pool.put(key, page);
return page;
}
// 清除线程变量
/**
* 获取带有默认分页参数的 Page 对象
*/
public static <T> Page<T> getPage(Class<T> clazz, Integer current, Integer size) {
int pageNum = current != null && current > 0 ? current : 1;
int pageSize = size != null && size > 0 ? size : 10;
PagePool pool = getPagePool();
String key = pool.generateKey();
Page<T> page = new Page<>(pageNum, pageSize);
pool.put(key, page);
return page;
}
/**
* 注册一个 Page 对象到池中(供 PageInterceptor 使用)
*/
public static <T> void registerPage(Page<T> page) {
PagePool pool = getPagePool();
String key = pool.generateKey();
pool.put(key, page);
}
/**
* 获取默认的 Page 对象(第一个注册的)
* 保持向后兼容性
*/
@SuppressWarnings("unchecked")
public static <T> Page<T> getDefaultPage(Class<T> clazz) {
PagePool pool = PAGE_POOL_HOLDER.get();
if (pool == null || pool.isEmpty()) {
return null;
}
// 返回第一个 Page 对象
return (Page<T>) pool.pool.values().stream().findFirst().orElse(null);
}
/**
* 通过 key 获取 Page 对象
*/
@SuppressWarnings("unchecked")
public static <T> Page<T> getPageByKey(String key) {
PagePool pool = PAGE_POOL_HOLDER.get();
if (pool == null) {
return null;
}
return (Page<T>) pool.get(key);
}
/**
* 获取 PagePool
*/
private static PagePool getPagePool() {
PagePool pool = PAGE_POOL_HOLDER.get();
if (pool == null) {
pool = new PagePool();
PAGE_POOL_HOLDER.set(pool);
}
return pool;
}
/**
* 清除指定 key 的 Page 对象
*/
public static void clearPage(String key) {
PagePool pool = PAGE_POOL_HOLDER.get();
if (pool != null) {
pool.remove(key);
}
}
/**
* 清除所有
*/
public static void clear() {
PAGE_HOLDER.remove();
PagePool pool = PAGE_POOL_HOLDER.get();
if (pool != null) {
pool.clear();
}
PAGE_POOL_HOLDER.remove();
}
}

View File

@@ -8,6 +8,9 @@ import javax.servlet.http.HttpServletResponse;
public class PageInterceptor implements HandlerInterceptor {
// 默认的 Page key用于获取默认分页参数
public static final String DEFAULT_PAGE_KEY = "default_page";
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
// 默认分页参数
@@ -39,9 +42,16 @@ public class PageInterceptor implements HandlerInterceptor {
}
}
// 创建 MyBatis-Plus 的 Page 对象并存储到 ThreadLocal
// 创建 MyBatis-Plus 的 Page 对象并注册到 PagePool
Page<?> page = new Page<>(pageNum, pageSize);
PageContext.setPage(page);
PageContext.registerPage(page);
// 将分页参数存储到 request 属性中,方便其他地方使用
request.setAttribute("pageNum", pageNum);
request.setAttribute("pageSize", pageSize);
request.setAttribute("pageCurrent", pageNum); // 兼容 current 参数名
request.setAttribute("pageSize", pageSize);
return true;
}
@@ -50,4 +60,4 @@ public class PageInterceptor implements HandlerInterceptor {
// 清除ThreadLocal中的数据防止内存泄漏
PageContext.clear();
}
}
}