spring获取上下文的方式

1.在web.xml里面配置

  

 <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath*:applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

ContextLoaderListener的做用就是启动Web容器时，自动装配ApplicationContext的配置信息。

由于它实现了ServletContextListener这个接口，在web.xml配置这个监听器，启动容器时，就会默认执行它实现的方法。

ContextLoaderListener启动的上下文为根上下文，DispatcherServlet所建立的上下文的的父上下文即为此根上下文，可在FrameworkServlet中的initWebApplicationContext中看出。

 

 

1.方式1:

package com.xp;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.context.ContextLoader;
import org.springframework.web.context.WebApplicationContext;

public class MyServlet extends HttpServlet{

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	
	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		WebApplicationContext context = ContextLoader.getCurrentWebApplicationContext();
		System.out.println(context);
	}
	
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		
	}

}

 

 

 

Spring Junit4  获取Bean

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath:/spring/applicationContext-*.xml"})
public class DataSourceTest implements ApplicationContextAware{
    
    private ApplicationContext applicationContext;
    
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
    
    @Test
    public void testDict() throws Exception {
        DruidDataSource dataSource = (DruidDataSource)applicationContext.getBean("slave01DataSource");
        String sql = "select * from C1_1 limit 4";
        PreparedStatement prepareStatement = dataSource.getConnection().prepareStatement(sql);
        ResultSet rs = prepareStatement.executeQuery();
        while (rs.next()) {
            int int1 = rs.getInt("id");
            String CsCode = rs.getString("CsCode");
        }
        System.out.println();
    }