使用比较器的 Java 集合二分搜索不起作用

Question

我的 Java Collection 的二分搜索无法正常工作。它能够找到一些元素，但无法找到一些元素。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。或者我的二分搜索实现有些错误？

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......在排序时我应该通过忽略大小写来排序 下面的东西现在可以工作了

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());