Spring+Hibernate 實現不一樣域名訪問同一項目，自定義Filter根據域名選擇對應的數據源

AbstractRoutingDataSource 實現切換數據源的原理

查看這個類能夠發現。它繼承了DataSource，那麼找到他的getConnection方法

public Connection getConnection() throws SQLException {

return this.determineTargetDataSource().getConnection();
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}

protected DataSource determineTargetDataSource() {

Assert.notNull(this.resolvedDataSources, "DataSource router not initialized");

Object lookupKey = this.determineCurrentLookupKey();

DataSource dataSource = (DataSource)this.resolvedDataSources.get(lookupKey);

if(dataSource == null && (this.lenientFallback || lookupKey == null)) {

    dataSource = this.resolvedDefaultDataSource;

}

if(dataSource == null) {

    throw new IllegalStateException("Cannot determine target DataSource for lookup key [" + lookupKey + "]");

} else {

    return dataSource;

}
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}

能夠看出關鍵代碼determineTargetDataSource中，這裏處理了數據源切換，那麼只須要寫一個子類，將determineCurrentLookupKey這個方法重寫下，便可作到數據源切換。

數據源配置

用到的部分代碼以下，其他的用項目中的便可：

-數據庫配置文件

#------------main MySQL ------------

hibernate.dialect=org.hibernate.dialect.MySQLDialect

jdbc.driver=com.mysql.jdbc.Driver

jdbc.url=jdbc:mysql://47.94.18.202:3306/jxncpshop?useUnicode=true&characterEncoding=UTF-8

jdbc.username=root

jdbc.password=root

#------------main MySQL2 ------------

#openData.hibernate.dialect=org.hibernate.dialect.MySQLDialect

openData.jdbc.driver=com.mysql.jdbc.Driver

openData.jdbc.url=jdbc:mysql://47.94.18.202:3306/jnncpshop?useUnicode=true&characterEncoding=UTF-8

openData.jdbc.username=root

openData.jdbc.password=root

url1=http://www.jnncpshop.com:8081/

url2=http://www.jxncpshop.com:8081/

applicationContext.xml的配置

此處代碼中須要主義的地方有：dataSource配置的key要和後面修改數據庫是的名稱保持一致，

-切換數據源和事務管理的前後順序：這裏經過order 來設置優先級，保證切換數據源的切面在事務管理以前

-sessionFactory配置注意的地方的地方：將默認的數據庫配置取消，否則會沒法切換

1：動態選擇數據源 方法類

import org.springframework.jdbc.datasource.lookup.AbstractRoutingDataSource;

/**

• Created by Administrator on 2019/1/16.

*/

public class ChooseDataSourceextends AbstractRoutingDataSource{

@Override

protected Object determineCurrentLookupKey() {
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String dataSource = HandleDataSource.getDataSource();

HandleDataSource.clearDataSource();//每次設置完清除，保證獲取默認數據庫

return dataSource;
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}

}

2：數據源切換類

package com.ewebtd.eshop.admin.common;

/**

• Created by Administrator on 2019/1/16.

*/

public class HandleDataSource {

// 數據源名稱線程池,ThreadLocal是線程安全的，而且不能在多線程之間共享

public static final ThreadLocalholder =new ThreadLocal();
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public static void setDataSource(String dataSource){

holder.set(dataSource);

}

public static String getDataSource(){

return ((String)holder.get());

}

public static void clearDataSource() {

holder.remove();

}

}

3.數據源名稱配置類

/**

• 數據源配置名稱--與配置文件中的key同名

• Created by Administrator on 2019/1/16.

*/

public class DataSourceConst {

public static final StringDEFAULT ="default";

public static final StringSITE_MAIN ="siteMain";

}

4.自定義Filter實現根據域名去在每次請求前判斷要選擇的數據源

import com.ewebtd.eshop.admin.common.DataSourceConst;

import com.ewebtd.eshop.admin.common.HandleDataSource;

import javax.servlet.*;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import java.io.BufferedReader;

import java.io.FileReader;

import java.io.IOException;

import java.util.Properties;

/**

• Created by Administrator on 2019/1/16.

*/

public class ChooseDataSourceFilterimplements Filter{

@Override

public void init(FilterConfig filterConfig)throws ServletException {
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}

@Override

public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)throws IOException, ServletException {
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if (!(servletRequestinstanceof HttpServletRequest) || !(servletResponseinstanceof HttpServletResponse)) {

throw new ServletException("OncePerRequestFilter just supports HTTP requests");

}

HttpServletRequest httpRequest = (HttpServletRequest) servletRequest;

HttpServletResponse httpResponse = (HttpServletResponse) servletResponse;

StringBuffer url = httpRequest.getRequestURL();

String tempContextUrl = url.delete(url.length() - httpRequest.getRequestURI().length(), url.length()).append("/").toString();

Properties properties =new Properties();

BufferedReader bufferedReader =new BufferedReader(new FileReader("E:/1227/source/trunk/eshop/eshopadmin/src/main/java/com/ewebtd/eshop/config/db.properties"));

properties.load(bufferedReader);

// if(tempContextUrl.equals("www.jnncpshop.com:8081/")){

if(tempContextUrl.equals(properties.getProperty("url1"))){
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HandleDataSource.setDataSource(DataSourceConst.SITE_MAIN);

}else if(tempContextUrl.equals(properties.getProperty("url2"))){

HandleDataSource.setDataSource(DataSourceConst.DEFAULT);

}

filterChain.doFilter(servletRequest, servletResponse);

return;

}

@Override

public void destroy() {
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}

}

5.在web.xml中配置一下，過濾全部請求，注意在過濾器執行鏈的順序

ChooseDataSourceFilter

com.ewebtd.eshop.admin.filter.ChooseDataSourceFilter

ChooseDataSourceFilter

/*

測試的話須要修改本機hosts文件，對127.0.0.1作域名映射，而後重啓電腦

啓動tomcat,效果如圖：