java 如何访问速度模板文件中的地图
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How to access map in velocity template file
提问by ved
when I passed a Map<String,String>in velocity template file, and when try to print the values of map it get sorted (on the basis of ASCII values).
当我传递一个Map<String,String>in 速度模板文件，并尝试打印地图的值时，它会被排序（基于 ASCII 值）。
I am doing as follows:
我正在做如下：
this is my velocity template file::
这是我的速度模板文件::
#set($tocList=${mapReference.mapValue})
#set($tocEntry="")
<div >
#foreach($tocEntry in $tocList.keySet())
<a href="#$tocEntry">$tocList.get($tocEntry)</a><br/>
#end
</div>
My Java code is :
我的Java代码是：
Map<String, String> map=new HashMap<String, String>();
Map<String,HashMap> m1=new HashMap<String, HashMap>();
\values that we want to print in template file
map.put("sdfhfg", "Df lm");
map.put("chdgfhd", "gBc Jk");
map.put("dghjdhdf", "gI Ml");
m1.put("mapValue", (HashMap) map);
VelocityEngine velocityEngine = VelocityEngineFactory.getVelocityEngine();
VelocityContext context = new VelocityContext();
context.put("img",model);
context.put("mapReference",m1);
context.put("iterator", new IteratorTool());
Template t = velocityEngine.getTemplate("tocTemplate.vm");
StringWriter writer = new StringWriter();
t.merge(context , writer);
System.out.println(writer);
Output is:
输出是：
<div>
<a href="#dghjdhdf">gI Ml</a><br/>
<a href="#chdgfhd">gBc Jk</a><br/>
<a href="#sdfhfg">Df lm</a><br/>
</div>
Why these values get sorted? I want to print map as it is.
为什么这些值被排序？我想按原样打印地图。
回答by Pau Kiat Wee
The order of the HasMap will not remain constant over time, from Javadoc:
HasMap 的顺序不会随着时间的推移保持不变，来自Javadoc：
This class makes no guarantees as to the order of the map; in particular, it does not guarantee that the order will remain constant over time.
此类不保证地图的顺序；特别是，它不保证订单会随着时间的推移保持不变。
To remain the order, you can consider use LinkedHashMapas following suggested:
为了保持顺序，您可以考虑使用LinkedHashMap如下建议：
This linked list defines the iteration ordering, which is normally the order in which keys were inserted into the map
这个链表定义了迭代顺序，通常是将键插入到映射中的顺序
