<dependency>
			    <groupId>com.baomidou</groupId>
			    <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
			    <version>3.1.0</version>
			</dependency>

/**
 * Copyright ? 2018 organization baomidou
 * <pre>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * <pre/>
 */
package com.baomidou.dynamic.datasource.toolkit;

import java.util.ArrayDeque;
import java.util.Deque;
import org.springframework.core.NamedInheritableThreadLocal;
import org.springframework.util.StringUtils;

/**
 * 核心基于ThreadLocal的切換數(shù)據(jù)源工具類
 *
 * @author TaoYu Kanyuxia
 * @since 1.0.0
 */
public final class DynamicDataSourceContextHolder {

  /**
   * 為什么要用鏈表存儲(準(zhǔn)確的是棧)
   * <pre>
   * 為了支持嵌套切換，如ABC三個service都是不同的數(shù)據(jù)源
   * 其中A的某個業(yè)務(wù)要調(diào)B的方法，B的方法需要調(diào)用C的方法。一級一級調(diào)用切換，形成了鏈。
   * 傳統(tǒng)的只設(shè)置當(dāng)前線程的方式不能滿足此業(yè)務(wù)需求，必須模擬棧，后進(jìn)先出。
   * </pre>
   */
  @SuppressWarnings("unchecked")
  private static final ThreadLocal<Deque<String>> LOOKUP_KEY_HOLDER = new NamedInheritableThreadLocal("dynamic-datasource") {
    @Override
    protected Object initialValue() {
      return new ArrayDeque();
    }
  };

  private DynamicDataSourceContextHolder() {
  }

  /**
   * 獲得當(dāng)前線程數(shù)據(jù)源
   *
   * @return 數(shù)據(jù)源名稱
   */
  public static String peek() {
    return LOOKUP_KEY_HOLDER.get().peek();
  }

  /**
   * 設(shè)置當(dāng)前線程數(shù)據(jù)源
   * <p>
   * 如非必要不要手動調(diào)用，調(diào)用后確保最終清除
   * </p>
   *
   * @param ds 數(shù)據(jù)源名稱
   */
  public static void push(String ds) {
    LOOKUP_KEY_HOLDER.get().push(StringUtils.isEmpty(ds) ? "" : ds);
  }

  /**
   * 清空當(dāng)前線程數(shù)據(jù)源
   * <p>
   * 如果當(dāng)前線程是連續(xù)切換數(shù)據(jù)源 只會移除掉當(dāng)前線程的數(shù)據(jù)源名稱
   * </p>
   */
  public static void poll() {
    Deque<String> deque = LOOKUP_KEY_HOLDER.get();
    deque.poll();
    if (deque.isEmpty()) {
      LOOKUP_KEY_HOLDER.remove();
    }
  }

  /**
   * 強制清空本地線程
   * <p>
   * 防止內(nèi)存泄漏，如手動調(diào)用了push可調(diào)用此方法確保清除
   * </p>
   */
  public static void clear() {
    LOOKUP_KEY_HOLDER.remove();
  }
}

/**
 * Copyright ? 2018 organization baomidou
 * <pre>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * <pre/>
 */
package com.baomidou.dynamic.datasource.toolkit;

import cn.hutool.core.date.LocalDateTimeUtil;
import com.alibaba.fastjson.JSON;
import org.springframework.core.NamedInheritableThreadLocal;
import org.springframework.util.StringUtils;

import java.util.ArrayDeque;
import java.util.Deque;

/**
 * 核心基于ThreadLocal的切換數(shù)據(jù)源工具類
 *
 * @author TaoYu Kanyuxia
 * @since 1.0.0
 */
public final class DynamicDataSourceContextHolder {

    /**
     * 為什么要用鏈表存儲(準(zhǔn)確的是棧)
     * <pre>
     * 為了支持嵌套切換，如ABC三個service都是不同的數(shù)據(jù)源
     * 其中A的某個業(yè)務(wù)要調(diào)B的方法，B的方法需要調(diào)用C的方法。一級一級調(diào)用切換，形成了鏈。
     * 傳統(tǒng)的只設(shè)置當(dāng)前線程的方式不能滿足此業(yè)務(wù)需求，必須模擬棧，后進(jìn)先出。
     * </pre>
     */
    private static final ThreadLocal<Deque<String>> LOOKUP_KEY_HOLDER = new NamedInheritableThreadLocal<Deque<String>>("dynamic-datasource") {
        // @Override
        // protected Deque<String> childValue(Deque<String> parentValue) {
        //     return new ArrayDeque<>();
        // }

        @Override
        protected ArrayDeque<String> initialValue() {
            return new ArrayDeque<>();
        }
    };

    private DynamicDataSourceContextHolder() {
    }

    /**
     * 獲得當(dāng)前線程數(shù)據(jù)源
     *
     * @return 數(shù)據(jù)源名稱
     */
    public static String peek() {
        Deque<String> strings = LOOKUP_KEY_HOLDER.get();
        String peek = strings.peek();
        String format = LocalDateTimeUtil.format(LocalDateTimeUtil.now(), "yyyy-MM-dd HH:mm:ss:SSS");
        System.out.printf("時間 %s 當(dāng)前線程 %s 獲得當(dāng)前線程數(shù)據(jù)源 %s 棧針 %s ", format, Thread.currentThread().getName(), peek, JSON.toJSONString(strings));
        System.out.println();
        return peek;
    }

    /**
     * 設(shè)置當(dāng)前線程數(shù)據(jù)源
     * <p>
     * 如非必要不要手動調(diào)用，調(diào)用后確保最終清除
     * </p>
     *
     * @param ds 數(shù)據(jù)源名稱
     */
    public static void push(String ds) {
        Deque<String> strings = LOOKUP_KEY_HOLDER.get();
        System.out.printf("時間 %s 當(dāng)前線程 %s 設(shè)置當(dāng)前線程數(shù)據(jù)源 %s 棧針 %s 引用 %s", LocalDateTimeUtil.format(LocalDateTimeUtil.now(), "yyyy-MM-dd HH:mm:ss:SSS"), Thread.currentThread().getName(), ds, JSON.toJSONString(strings), strings.hashCode());
        System.out.println();
        strings.push(StringUtils.isEmpty(ds) ? "" : ds);
        System.out.printf("時間 %s 當(dāng)前線程 %s 之后設(shè)置當(dāng)前線程數(shù)據(jù)源 %s 棧針 %s 引用 %s", LocalDateTimeUtil.format(LocalDateTimeUtil.now(), "yyyy-MM-dd HH:mm:ss:SSS"), Thread.currentThread().getName(), ds, JSON.toJSONString(strings), strings.hashCode());
        System.out.println();
    }

    /**
     * 清空當(dāng)前線程數(shù)據(jù)源
     * <p>
     * 如果當(dāng)前線程是連續(xù)切換數(shù)據(jù)源 只會移除掉當(dāng)前線程的數(shù)據(jù)源名稱
     * </p>
     */
    public static void poll() {
        Deque<String> deque = LOOKUP_KEY_HOLDER.get();
        System.out.printf("時間 %s 清空當(dāng)前線程 %s  棧針 %s ", LocalDateTimeUtil.format(LocalDateTimeUtil.now(), "yyyy-MM-dd HH:mm:ss:SSS"), Thread.currentThread().getName(), JSON.toJSONString(deque));
        System.out.println();
        String poll = deque.poll();
        System.out.printf("時間 %s 當(dāng)前線程 %s 清空 %s 棧針 %s ", LocalDateTimeUtil.format(LocalDateTimeUtil.now(), "yyyy-MM-dd HH:mm:ss:SSS"), Thread.currentThread().getName(), poll, JSON.toJSONString(deque));
        System.out.println();
        if (deque.isEmpty()) {
            LOOKUP_KEY_HOLDER.remove();
        }
    }

    /**
     * 強制清空本地線程
     * <p>
     * 防止內(nèi)存泄漏，如手動調(diào)用了push可調(diào)用此方法確保清除
     * </p>
     */
    public static void clear() {
        LOOKUP_KEY_HOLDER.remove();
    }
}

    /**
     * 設(shè)置當(dāng)前線程數(shù)據(jù)源
     * <p>
     * 如非必要不要手動調(diào)用，調(diào)用后確保最終清除
     * </p>
     *
     * @param ds 數(shù)據(jù)源名稱
     */
    public static void push(String ds) {
        Deque<String> strings = LOOKUP_KEY_HOLDER.get();
        System.out.printf("時間 %s 當(dāng)前線程 %s 設(shè)置當(dāng)前線程數(shù)據(jù)源 %s 棧針 %s 引用 %s", LocalDateTimeUtil.format(LocalDateTimeUtil.now(), "yyyy-MM-dd HH:mm:ss:SSS"), Thread.currentThread().getName(), ds, JSON.toJSONString(strings), strings.hashCode());
        System.out.println();
        strings.push(StringUtils.isEmpty(ds) ? "" : ds);
        System.out.printf("時間 %s 當(dāng)前線程 %s 之后設(shè)置當(dāng)前線程數(shù)據(jù)源 %s 棧針 %s 引用 %s", LocalDateTimeUtil.format(LocalDateTimeUtil.now(), "yyyy-MM-dd HH:mm:ss:SSS"), Thread.currentThread().getName(), ds, JSON.toJSONString(strings), strings.hashCode());
        System.out.println();
    }

package org.springframework.core;

import org.springframework.util.Assert;

public class NamedInheritableThreadLocal<T> extends InheritableThreadLocal<T> {
    private final String name;

    public NamedInheritableThreadLocal(String name) {
        Assert.hasText(name, "Name must not be empty");
        this.name = name;
    }

    public String toString() {
        return this.name;
    }
}

    /**
     * 為什么要用鏈表存儲(準(zhǔn)確的是棧)
     * <pre>
     * 為了支持嵌套切換，如ABC三個service都是不同的數(shù)據(jù)源
     * 其中A的某個業(yè)務(wù)要調(diào)B的方法，B的方法需要調(diào)用C的方法。一級一級調(diào)用切換，形成了鏈。
     * 傳統(tǒng)的只設(shè)置當(dāng)前線程的方式不能滿足此業(yè)務(wù)需求，必須模擬棧，后進(jìn)先出。
     * </pre>
     */
    private static final ThreadLocal<Deque<String>> LOOKUP_KEY_HOLDER = new NamedInheritableThreadLocal<Deque<String>>("dynamic-datasource") {
        @Override
        protected Deque<String> childValue(Deque<String> parentValue) {
            return new ArrayDeque<>();
        }

        @Override
        protected ArrayDeque<String> initialValue() {
            return new ArrayDeque<>();
        }
    };