Java web 常见对象的取值方法整理

一、从request中取值：

1.取param：

servlet:  request.getParameter()

request.getParameterValues()

jsp脚本：request.getParameter()

request.getParameterValues()

jstl/el:  ${param.name}

${paramaValues.names[0]}

struts ognl:<s:property value="#parameters.ParamName[0]"/>

2.取attribute：

servlet: request.getAttribute();

jsp脚本：request.getAttribute();

jstl/el:${attrName}（依次查找request、session和application中的属性，找到为止)

${requestScope.attrName}

struts ognl:<s:property value="#attrName">（依次查找request、session和application中的属性，找到为止)

<s:property value="#request.attrName">

二、从servletContext（application）中取值：

1.取InitParam:

servlet: getServletContext().getInitParam("parmaName");

getServletConfig().getServletContext.getInitParam("paramName");

(getServletConfig().getInitParam("parmaName")和getInitParam("parmaName")是取得当前servlet中的initParam);

jsp脚本：application.getInitParam("paramName");

config.getServletContext().getInitParam("paramName");

config.getInitParam("paramName");

jstl/el: ${initParam.paramName}

2.取attribute：

servlet: getServletContext().getAttribute("attrName");

getServletConfig().getServletContext.getAttribute("attrName");

jsp脚本：application.getAttribute("attrName");

jstl/el:${attrName}（依次查找request、session和application中的属性，找到为止)

${applicationScope.attrName}

struts ognl:<s:property value="#attrName">（依次查找request、session和application中的属性，找到为止)

<s:property value="#application.attrName">

三、从session中取值：

取attribute：

servlet: request.getSession().getAttribute("attrName");

jsp脚本：session.getAttribute("attrName");

jstl/el: ${attrName}（依次查找request、session和application中的属性，找到为止)

${sessionScope.attrName}

struts ognl:<s:property value="#attrName">（依次查找request、session和application中的属性，找到为止)

<s:property value="#session.attrName">

四、从page中取值：

取attribute:

jsp脚本：pageContext.getAttribute(name);

jstl/el: ${pageContext.attrName}

五、从cookie中取值：

servlet: request.getCookies();

jsp脚本：request.getCookies();

jstl/el: ${cookie.cookieName.value}

Java web 常见对象的取值方法整理