hibernate+json报no session

含有外键的po，采用lazy加载模式时，session会在进入service(action)前关闭。

方案1：

可在web.xml中配置：

<!-- 延迟加载 -->

<filter>
<filter-name>OpenSessionInViewFilter</filter-name>
<filter-class>org.springframework.orm.hibernate3.support.OpenSessionInViewFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>OpenSessionInViewFilter</filter-name>
<url-pattern>*.action</url-pattern>
</filter-mapping>

<filter-mapping>
<filter-name>OpenSessionInViewFilter</filter-name>
<url-pattern>*.jsp</url-pattern>
</filter-mapping>

注意要配置在struts的过滤器前。

方案2：

public <T> void write(List<T> list,String... values){

String [] ignore=null;

HttpServletResponse response = ServletActionContext.getResponse();

response.setContentType("text/html;charset=UTF-8");

response.setCharacterEncoding("UTF-8");// 防止弹出的信息出现乱码

PrintWriter writer=null;

try {

writer = response.getWriter();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

JsonConfig jsonConfig = new JsonConfig();

jsonConfig.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT);

if (values != null) {

ignore =new String[values.length];

for (int i = 0; i < values.length; i++) {

ignore[i]=values[i];

}

}

jsonConfig.setExcludes(ignore);

JSONArray json =JSONArray.fromObject(list, jsonConfig);

//防止因嵌套产生的死循环

System.out.println(json);

writer.print(json);

}

jsonConfig.setExcludes(ignore);为给json添加过滤字段。

转载于:https://my.oschina.net/u/2286010/blog/635514