Posted on 2009-08-25 14:38
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dwr
使用dwr我們可以動態請求一個頁面內容到當前頁：一下是代碼：
1，后臺方法：
public String getInclude() throws ServletException, IOException {
WebContext ctx = WebContextFactory.get();
System.out.println(ctx.getCurrentPage());
ctx.getHttpServletRequest().setAttribute("test", "hello ,test forward");
return ctx.forwardToString("/iclude.jsp");
}
2，dwr配置：
<create javascript="testinclude" creator="new">
<param name="class" value="com.dwr.TestInclude"/>
</create>
3，頁面：
<html>
<head>
<base href="<%=basePath%>">
<script type="text/javascript" src="dwr/engine.js"></script>
<script type="text/javascript" src="dwr/util.js"></script>
<script type="text/javascript" src="dwr/interface/testinclude.js"></script>
<script type="text/javascript">
function getInClude(){
testinclude.getInclude(
function(data){
dwr.util.setValue("fq",data,{ escapeHtml:false });
}
);
}
</script>
</head>
<body>
<input type="button" value="include page"
onclick="javascript:getInClude()" />
<div id="fq">
</div>
</body>
</html>
2，其中使用了
WebContext ctx = WebContextFactory.get();
ctx.forwardToString("/iclude.jsp");
查看dwr源代碼：
getServletContext().getRequestDispatcher(url).forward(realRequest, fakeResponse);
其中：fakeResponse
HttpServletResponse fakeResponse = new SwallowingHttpServletResponse(realResponse, sout, realResponse.getCharacterEncoding());
而SwallowingHttpServletResponse使用了WriterOutputStream
public SwallowingHttpServletResponse(HttpServletResponse response, Writer sout, String characterEncoding)
{
super(response);
pout = new PrintWriter(sout);
outputStream = new WriterOutputStream(sout, characterEncoding);
this.characterEncoding = characterEncoding;
}
WriterOutputStream：也就是對 ServletOutputStream的封裝。
public final class WriterOutputStream extends ServletOutputStream