JNDI使用

JNDI使用

jndi配置数据库

tomcat使用的是Tomcat 6.0.18版本

1.先在工程的WEB-INF目录下的META-INF下新建context.xml中添加配置resource，如下:

<Resource   
  name="jdbc/mysql"  
  type="javax.sql.DataSource"  
  driverClassName="com.mysql.jdbc.Driver"  
  password="123456"  
  maxIdle="2"  
  maxWait="5000"  
  username="root"  
  url="jdbc:mysql://localhost:3306/test"  
  maxActive="4"/> 

2.将mysql的connet jar放入到%TOMCAT_HOME%\common\lib下面。

3.写测试的例子：

public String testMain() throws SQLException, NamingException{
		Context ctx = null;   
	    DataSource ds = null;   
	    Connection conn = null;   
	    Statement stmt = null;   
	    ResultSet rs = null;   	  
	    try {   
	        ctx = new InitialContext();   
	        if (ctx == null){
	        	System.out.println("no context");   
	        	return "no context";
	        }

	        ds = (DataSource) ctx.lookup("java:comp/env/jdbc/mysql");   
	        if (ds == null)  {
	        	 System.out.println("no datasource");   
		         return "no datasource";
	        }	           
	        conn = ds.getConnection();   
	        stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,   
	        ResultSet.CONCUR_READ_ONLY);   
	        String strSql = "select * from pmuser";   
	        rs = stmt.executeQuery(strSql);   
	        while (rs.next()) {   
	            System.out.println(rs.getString(2));   
	        }  
	        return "sucess";
	    } catch (Exception ex) {   
	        ex.printStackTrace();   
	        System.out.println(ex.toString());   
	    } finally {   
	        if (rs != null)   
	            rs.close();   
	        if (stmt != null)   
	            stmt.close();   
	        if (conn != null)   
	            conn.close();   
	        if (ctx != null)   
	            ctx.close();   
	    } 
	    return "error";
	}

jsp页面代码

<%
    	String br="<br />";
    	out.println("Start Test JNDI"+br);
	    TestMysqlJndi tm=new TestMysqlJndi();
	    String ret=tm.testMain();
	    out.println("Return String : "+ret+br);
	    out.println("End Test Jndi <br />"+br);
    %>

自定义JNDI

1、写自定义的类

public class MyBean {
		private String foo = "Default Foo";
		private int bar = 0;
		  public String getFoo() {
		    return (this.foo);
		  }
		  public void setFoo(String foo) {
		    this.foo = foo;
		  }
		  public int getBar() {
		    return (this.bar);
		  }
		  public void setBar(int bar) {
		    this.bar = bar;
		  }
	}

2.在context.xml中添加如下配置：

<Resource name="bean/MyBeanFactory" auth="Container"
            type="com.demo.MyBean"
            factory="org.apache.naming.factory.BeanFactory"
            bar="23"/>   

其中bar="23"是对MyBean的初始化

3.写测试代码：

public String testMethod() throws NamingException{
		Context initCtx=new InitialContext();
		Context ctx=(Context)initCtx.lookup("java:comp/env");
		MyBean bean=(MyBean)ctx.lookup("bean/MyBeanFactory");
		StringBuffer ret=new StringBuffer();
		ret.append("foo = ").append(bean.getFoo()).append(", bar = ").append(bean.getBar());		
		System.out.println(ret.toString());
		return ret.toString();
	}

jsp页面：

<%
		String br="<br />";
		out.println("Start Test JNDI"+br);
		    TestJndiMain tm=new TestJndiMain();
		    String ret=tm.testMethod();
		    out.println("Return String : "+ret+br);
		    out.println("End Test Jndi <br />"+br);
		%>

附件为完整的例子和mysql的驱动