通过Java和PrimeFaces生成直方图 [英] Generating Histogram through Java and PrimeFaces
本文介绍了通过Java和PrimeFaces生成直方图的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我在通过Java素面生成直方图时遇到麻烦.我有这个xhtml文件.
I am having trouble in generating histogram through java prime faces.I have this xhtml file.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:p="http://primefaces.org/ui">
<ui:define name="content">
<h1 class="title ui-widget-header ui-corner-all">Charts - Bar</h1>
<div class="entry">
<p>BarChart displays a CartesianChartModel.</p>
<p:barChart id="basic" value="#{ChartBean.categoryModel}" legendPosition="ne"
title="Basic Bar Chart" min="0" max="200" style="height:300px"/>
</div>
</ui:define>
</html>
我也有这个ChartBean.java文件，上面定义了ChartBean.categoryModel
I also have this ChartBean.java file which has ChartBean.categoryModel defined above
package exmpl;
//package org.primefaces.examples.view;
import java.io.Serializable;
import java.util.ArrayList;
import exmpl.controller.QueryBean;
import org.primefaces.model.chart.CartesianChartModel;
import org.primefaces.model.chart.ChartSeries;
public class ChartBean implements Serializable {
private CartesianChartModel categoryModel;
public ChartBean() {
System.out.print("Inside constructir");
createCategoryModel();
}
public CartesianChartModel getCategoryModel() {
return categoryModel;
}
private void createCategoryModel() {
System.out.print("Inside Function Category Model");
QueryBean obj = new QueryBean();
ArrayList<Integer> employeeage = obj.employeeAge();
System.out.print("After accessing QueryBean");
ArrayList<Integer> grp1 = new ArrayList<Integer>();
ArrayList<Integer> grp2 = new ArrayList<Integer>();
ArrayList<Integer> grp3 = new ArrayList<Integer>();
ArrayList<Integer> grp4 = new ArrayList<Integer>();
ArrayList<Integer> grp5 = new ArrayList<Integer>();
ArrayList<Integer> grp6 = new ArrayList<Integer>();
ArrayList<Integer> grp7 = new ArrayList<Integer>();
for(Integer i : employeeage)
{
if(i.intValue() > 0 && i.intValue() <= 20 )
{
grp1.add(i);
}
else if(i.intValue() > 20 && i.intValue() <= 40 )
{
grp2.add(i);
}
else if(i.intValue() > 40 && i.intValue() <= 50 )
{
grp3.add(i);
}
else if(i.intValue() > 50 && i.intValue() <= 60 )
{
grp4.add(i);
}
else if(i.intValue() > 60 && i.intValue() <= 70 )
{
grp5.add(i);
}
else if(i.intValue() > 70 && i.intValue() <= 80 )
{
grp6.add(i);
}
else
{
grp7.add(i);
}
}
int size1 = grp1.size();
int size2 = grp2.size();
int size3 = grp3.size();
int size4 = grp4.size();
int size5 = grp5.size();
int size6 = grp6.size();
int size7 = grp7.size();
categoryModel = new CartesianChartModel();
ChartSeries employee = new ChartSeries();
patient.setLabel("Employees");
employee.set("0-20", size1);
employee.set("21-40", size2);
employee.set("41-50", size3);
employee.set("51-60", size4);
employee.set("61-70", size5);
employee.set("71-80", size6);
employee.set("80+", size7);
categoryModel.addSeries(employee);
}
}
此外，第一个xhtml中的ui.xhtml模板看起来像这样
ALso the ui.xhtml template in the first xhtml looks like this
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui">
<f:view contentType="text/html">
<h:head>
<f:facet name="first">
<meta http-equiv="X-UA-Compatible" content="IE=Edge"/>
<meta content='text/html; charset=UTF-8' http-equiv="Content-Type"/>
<title>PrimeFaces - ShowCase</title>
<!-- <link rel="shortcut icon" type="image/png" href="#{request.contextPath}/images/favicon.png" /> -->
</f:facet>
<link type="text/css" rel="stylesheet" href="#{request.contextPath}/css/default.css" />
<link type="text/css" rel="stylesheet" href="#{request.contextPath}/css/syntaxhighlighter/syntaxhighlighter.css" />
<ui:insert name="head"></ui:insert>
<script type="text/javascript">
$(function() {$('.sidebar a').hover(function() {$(this).toggleClass('ui-state-hover');})});
</script>
<script type="text/javascript">
var _gaq = _gaq || [];
_gaq.push(['_setAccount', 'UA-12200033-3']);
_gaq.push(['_trackPageview']);
(function() {
var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js';
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
})();
</script>
</h:head>
<h:body>
<div id="header" class="ui-widget ui-widget-header">
<div id="logo">
<img src="#{request.contextPath}/images/logo.png" alt="Logo"/>
</div>
</div>
<div id="page" class="ui-widget">
<div id="sidebar" class="ui-widget-content ui-corner-bottom ui-helper-clearfix ui-shadow">
<h3 class="ui-widget ui-widget-header ui-corner-all submenu-title ui-state-highlight">Charts</h3>
<div class="submenu-content">
<table>
<tr>
<td style="width:33%">
<ul>
<li><a href="#{request.contextPath}/ui/barChart.jsf">Bar</a></li>
</ul>
</td>
<td style="width:33%">
<ul>
</ul>
</td>
</tr>
</table>
</div>
</div>
<div id="content">
<div class="post">
<ui:insert name="content">...</ui:insert>
</div>
</div>
<div style="clear: both;"></div>
</div>
<ui:insert name="footer">
<div id="footer" class="ui-widget ui-widget-header ui-corner-all">
<p class="copyright">Running #{build.primefacesVersion} on #{build.jsfVersion}</p>
</div>
</ui:insert>
<ui:insert name="status">
<p:ajaxStatus style="width:64px;height:64px;position:fixed;right:5px;bottom:5px">
<f:facet name="start">
<p:graphicImage value="/images/loading.gif" />
</f:facet>
<f:facet name="complete">
<h:outputText value="" />
</f:facet>
</p:ajaxStatus>
</ui:insert>
<ui:insert name="highlight">
<script language="javascript" src="#{request.contextPath}/syntaxhighlighter/scripts/sh.js"></script>
<script language="javascript">
SyntaxHighlighter.all();
</script>
</ui:insert>
</h:body>
</f:view>
</html>
现在的问题是，当我运行上述文件时，什么也没有发生，并且看不到任何显示.我对此并不陌生，因此无法指出我在哪里出错了.有人可以帮我吗?
Now the problem is that when I run the above files nothing happens and no display is visible.I am new to this and hence unable to point where I am making an error.Can anyone help me in this?
更新:当我在xhtml文件上运行时，我什至没有看到inside constructor在控制台上打印的inside constructor是用ChartBean()构造函数编写的
UPDATE: When I run above xhtml file I do not even see inside constructor printed on console which is written on ChartBean() constructor
推荐答案
当然，您看不到构造函数的输出，因为实际上从来不会使用提供的代码来调用它.要使您的bean在xhtml页面中可访问，必须使用 @Named 或 @ManagedBean 批注.当您执行此操作时，当您在xhtml中引用该bean的实例时(根据其作用域)，将创建该bean的实例.
Of course you can't see the output from the constructor as it is really never called using the provided code. To make your bean accessible in your xhtml page, you must use @Named or @ManagedBean annotation. When you do this, instance of the bean will be created when you refer to it in xhtml(based on its scope).
@ManagedBean
@ViewScoped
public class ChartBean implements Serializable {
...
}
然后您可以像这样在xhtml中使用它:
Then you can use it in your xhtml like this:
#{chartBean.categoryModel}
这篇关于通过Java和PrimeFaces生成直方图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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