上一篇 Java WebService学习笔记 – Axis(一)
前一篇博文中简单介绍了Axis的使用方法，这篇将介绍一些Axis的一些高级特性
Axis中Handler的使用
Handler的作用和Struts中Filter类似，主要用于访问之前或之后做一些特别的处理。主要包括权限验证，授权，访问量统计等等。
下面一个简单的例子介绍一下具体的使用方法
访问量统计
关于访问量统计，最简单的方法是在类内部添加一个静态同步的字段，每次访问对其进行加1.但是在WebService的中可能你只有一个class文件，此时不能也不允许在类中进行修改；而且在类中添加方法的话侵入性比较高。
Handler处理类：CountHandler.java
package com.handler;import org.apache.axis.AxisFault;
import org.apache.axis.MessageContext;
import org.apache.axis.handlers.BasicHandler;public class CountHandler extends BasicHandler
{private static final long serialVersionUID = 6788857289474496020L;private long visitCount = 0L;@Override
public void invoke(MessageContext msgCtx) throws AxisFault
{visitCount++;String className = (String)msgCtx.getProperty("className");System.out.println("class:"+className+" current visit count :"+visitCount);
}
}
将CountHandler.java编译后放到服务器webapps/axis/WEB_INF/classes/com/handler/下。
在上一篇笔记中的<service>中添加Handler处理
<service name="Answer" provider="java:RPC">
<span style="color:#ff0000;"><requestFlow>
<handler type="java:com.handler.CountHandler"/>
</requestFlow></span>
<parameter name="className" value="com.webservice.wsdd.Answer"/>
<parameter name="allowedMethods" value="*"/>
<beanMapping
qname="bean:Question"
xmlns:bean="BeanManger"
languageSpecificType="java:com.webservice.wsdd.Question"
/>
<span style="color:#ff0000;"><responseFlow>
<handler type="java:com.handler.CountHandler"/>
</responseFlow></span>
</service>
在访问之前或之后都是可以的，两次都会创建不同的对象进行处理，处理结果如下
class:com.webservice.wsdd.Answer current visit count :1
read question:先有鸡还是先有蛋！
class:com.webservice.wsdd.Answer current visit count :1
class:com.webservice.wsdd.Answer current visit count :2
read question:先有鸡还是先有蛋！
class:com.webservice.wsdd.Answer current visit count :2
验证
首先要弄清楚验证和授权的概念，以普通的web应用为例，当你点击一个菜单时
验证：验证用户名密码是否正确
授权：前提是验证通过.根据用户名查询出访问权限，跟菜单的访问权限进行逻辑处理，如果有权限访问，则授权访问，否则，拒绝访问
下面给出一个简单的验证的例子
VerifyHandler.java
package com.handler;import org.apache.axis.AxisFault;
import org.apache.axis.MessageContext;
import org.apache.axis.handlers.BasicHandler;
import org.apache.axis.security.AuthenticatedUser;
import org.apache.axis.security.SecurityProvider;
import org.apache.axis.security.simple.SimpleSecurityProvider;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;public class VerifiyHandler extends BasicHandler
{private static final long serialVersionUID = 129414778283139001L;Log log = LogFactory.getLog(VerifiyHandler.class);@Override
public void invoke(MessageContext msgCtx) throws AxisFault
{
//1.获取安全机制
SecurityProvider provider = (SecurityProvider) msgCtx.getProperty("securityProvider");if(provider == null)
{
provider = new SimpleSecurityProvider();
msgCtx.setProperty("securityProvider", provider);
}//2.验证访问，如果验证通过返回AuthenticatedUser对象，否则返回null
AuthenticatedUser user = provider.authenticate(msgCtx);if(user == null)
{
log.info("verify failed");
throw new AxisFault("username or password not correct,visit refused");
}//为后面授权进行准备...
msgCtx.setProperty("authenticatedUser", user);
msgCtx.setProperty("yourRole", "007");log.info("verify success,username:"+user.getName());
}
}
和访问量统计处理步骤类似，配置文件如下
<service name="Answer" provider="java:RPC">
<span style="color:#ff0000;"><requestFlow>
<handler type="java:com.handler.VerifiyHandler"/>
<handler type="java:com.handler.CountHandler"/>
</requestFlow>
</span><parameter name="className" value="com.webservice.wsdd.Answer"/>
<parameter name="allowedMethods" value="*"/>
<beanMapping
qname="bean:Question"
xmlns:bean="BeanManger"
languageSpecificType="java:com.webservice.wsdd.Question"
/>
</service>
客户端访问时需要在原有的Call对象中设置username和password属性，属性值的映射内容可以在\webapps\axis\WEB-INF\users.lst中找到
call.setUsername("user3");
call.setPassword("pass3");
运行结果如下
- verify failed
- verify success,username:user3
class:com.webservice.wsdd.Answer current visit count :1
read question:先有鸡还是先有蛋！
授权
AuthorizeHandler.java
package com.handler;import java.util.StringTokenizer;import org.apache.axis.AxisFault;
import org.apache.axis.MessageContext;
import org.apache.axis.handlers.BasicHandler;
import org.apache.axis.security.AuthenticatedUser;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;public class AuthorizeHandler extends BasicHandler
{private static final long serialVersionUID = -8124974403139594724L;Log log = LogFactory.getLog(this.getClass());/**
*
*/
@Override
public void invoke(MessageContext msgContext) throws AxisFault {AuthenticatedUser user = (AuthenticatedUser) msgContext.getProperty("authenticatedUser");if(user!=null)
{
String role = (String)msgContext.getProperty("yourRole");String roles = (String)msgContext.getProperty("allowedRoles");for (StringTokenizer t = new StringTokenizer(roles, ",");t.hasMoreTokens();) {
String allowedrole = t.nextToken();
if(allowedrole.contains(role))
{
log.info("authorize pass! welcome "+role);
return;
}
}log.info("sorry,you did not have the permitions!");
throw new AxisFault("sorry,you did not have the permitions!");
}
else
{
log.info("verify not pass,will not authorize!");
throw new AxisFault("verify not pass,will not authorize!");
}
}}
配置如下
<service name="Answer" provider="java:RPC">
<requestFlow>
<handler type="java:com.handler.VerifiyHandler"/>
<span style="color:#ff0000;"><handler type="java:com.handler.AuthorizeHandler"/></span>
<handler type="java:com.handler.CountHandler"/>
</requestFlow>
<parameter name="className" value="com.webservice.wsdd.Answer"/>
<parameter name="allowedMethods" value="*"/>
<span style="color:#ff0000;"><parameter name="allowedRoles" value="007,M"/></span>
<beanMapping
qname="bean:Question"
xmlns:bean="BeanManger"
languageSpecificType="java:com.webservice.wsdd.Question"
/>
</service>
运行结果如下
- verify success,username:user3
- authorize pass! welcome 007
class:com.webservice.wsdd.Answer current visit count :1
read question:先有鸡还是先有蛋！
