Java Collection 使用比较器的二进制搜索不工作

Question

我的 Java Collection 的二进制搜索工作不正常。它能够找到一些元素，但找不到一些元素。我不知道是什么问题。列表的大小是否有限制？我正在使用 java 7. 或者我的二分查找实现有问题？

List<ManageDiseaseSearchBean> allDiseaseList=diseaseController.fetchAllDiseases();
// It fetches all diseases from database -- ordered by diseaseName asc. It has 12000 records

 class SortingComp implements Comparator<ManageDiseaseSearchBean> {
            @Override
            public int compare(ManageDiseaseSearchBean o1, ManageDiseaseSearchBean o2) {
                 return o1.getDiseaseName().compareTo(o2.getDiseaseName());

            }
            }

 Collections.sort(allDiseaseList,new SortingComp());
//sorting done via comparator

//searching implementation
 class DiseaseNameComp implements Comparator<ManageDiseaseSearchBean>{

     public int compare(ManageDiseaseSearchBean e1, ManageDiseaseSearchBean e2) {                                                                               
         return e1.getDiseaseName().trim().compareToIgnoreCase(e2.getDiseaseName().trim());                                      
         }
         }

     ManageDiseaseSearchBean searchKey = new ManageDiseaseSearchBean();
     searchKey.setDiseaseName(diseaseName);
     searchKey.setDiseaseCode(orphaNumber);
     int index = Collections.binarySearch(allDiseaseList, searchKey, new DiseaseNameComp());

Answer 1

多么愚蠢的错误...排序时我应该忽略大小写下面的东西现在可以使用了

List<ManageDiseaseSearchBean> allDiseaseList=diseaseController.fetchAllDiseases();

class DiseaseNameComp implements Comparator<ManageDiseaseSearchBean>{

 public int compare(ManageDiseaseSearchBean e1, ManageDiseaseSearchBean e2) {                                                                               
     return e1.getDiseaseName().trim().compareToIgnoreCase(e2.getDiseaseName().trim());                                      
     }
     }


Collections.sort(allDiseaseList,new DiseaseNameComp());

 ManageDiseaseSearchBean searchKey = new ManageDiseaseSearchBean();
 searchKey.setDiseaseName(diseaseName);
 searchKey.setDiseaseCode(orphaNumber);
 int index = Collections.binarySearch(allDiseaseList, searchKey, new DiseaseNameComp());

Java Collection 使用比较器的二进制搜索不工作

Java Collection Binary Search using Comparator not working

java

binary-search

comparator