Java 比较两个数组以仅检索JSP中的精确匹配,同时保留下拉列表中的显示顺序
我想在选项窗格和下拉列表中显示userBrands作为所选元素,需要显示完整的品牌列表。选中条件->brands.containsbrand.toLowerCase.trims时,将显示bat、cat和batting元素,而不是仅显示bat和catJava 比较两个数组以仅检索JSP中的精确匹配,同时保留下拉列表中的显示顺序,java,jsp,Java,Jsp,我想在选项窗格和下拉列表中显示userBrands作为所选元素,需要显示完整的品牌列表。选中条件->brands.containsbrand.toLowerCase.trims时,将显示bat、cat和batting元素,而不是仅显示bat和cat String brands=""; String userBrands[]=new String[30]; String brandslist[]= {"bat", "cat", "ant", "batting", "antenna"}; if(u
String brands="";
String userBrands[]=new String[30];
String brandslist[]= {"bat", "cat", "ant", "batting", "antenna"};
if(user.get("brand")!=null && !user.get("brand").isEmpty()){
brands = user.get("brand").toLowerCase();
System.out.println("BRANDS: " + brands); //here bat and cat retrieved from the database //Output: BRANDS: bat, cat
userBrands = brands.split(",");
}
for(String brand:brandslist){
if(brands.contains(brand.toLowerCase().trim())){%>
<option selected="selected" value="<%=brand.trim().toLowerCase()%>"><%=brand.trim()%></option>
<%}else{%>
<option value="<%=brand.trim().toLowerCase()%>"><%=brand.trim()%></option>
<%}
}
如果我尝试使用以下2个循环,则不会维持顺序,即下拉列表中先出现选定循环,然后出现未选定循环:
if(user.get("brand")!=null && !user.get("brand").isEmpty()){
brands = user.get("brand").toLowerCase();
System.out.println("BRANDS: " + brands);
userBrands = brands.split(",");
}
for(int p=0; p<brandlist.length; p++){
brandlist[p]=brandlist[p].trim().toLowerCase();
}
for(int q=0; q<userBrands.length; q++){
userBrands[q]=userBrands[q].trim().toLowerCase();
}
List<String> masterList = new ArrayList<String>();
List<String> selectedList = new ArrayList<String>();
List<String> unSelectedList = new ArrayList<String>();
masterList = Arrays.asList(brandlist);
for(int i=0; i<userBrands.length; i++){
for(int j=0; j<brandlist.length; j++){
if(userBrands[i].trim().equalsIgnoreCase(brandlist[j].trim())){
%>
<option selected="selected" value="<%=userBrands[i].trim()%>"><%=userBrands[i].trim()%></option>
<%
}
}
}
selectedList = Arrays.asList(userBrands);
for(String ms: masterList){
unSelectedList.add(ms);
for(String s: selectedList){
if(s.equalsIgnoreCase(ms)){
unSelectedList.remove(s);
}
}
}
for(String unStr: unSelectedList){%>
<option value="<%=unStr.trim()%>"><%=unStr.trim()%></option>
<%}%>
我所希望的是,只有通过user.getbrand.toLowerCase从数据库中获得的选项才能在选项中显示为选中的选项,而不是像在第一个代码段中击球那样额外显示,而且下拉列表中品牌的显示顺序与原始数组->brandslist[]相同。第一个代码段可以进行一些操作。您需要使用equals方法来比较值,而不是contains。此外,在下面的代码中,我添加了额外的变量find,通过与userBrands数组进行比较来检查brandslist中是否有值,以及将选择或不选择的选项,即:
<%
String brands="";
String userBrands[];
String brandslist[]= {"bat", "cat", "ant", "batting", "antenna"};
if(user.get("brand")!=null && !user.get("brand").isEmpty()){
brands = user.get("brand").toLowerCase();
System.out.println("BRANDS: " + brands);
userBrands = brands.split(",");
}
//out.println(Arrays.toString(userBrands));
// to check if value there or not
boolean found;
for(int i= 0 ;i<brandslist.length ;i++){
found = false;
for(int j= 0 ;j<userBrands.length ;j++){
if(userBrands[j].equals(brandslist[i].toLowerCase().trim())){ %>
<option selected='selected' value='<%=brandslist[i].toLowerCase().trim()%>'><%=brandslist[i].trim()%></option>
<%
//value there
found = true;
}
}
//value not there found will remain false and below code will get executed
if(!found){ %>
<option value='<%=brandslist[i].trim().toLowerCase()%>'><%=brandslist[i].trim()%></option>
<%}
}%>