Question

我有Collection<Student>并希望返回与过滤器比较的学生列表。为此，我有以下代码

public Collection<Student> findStudents(String filter) {

    return // ?
}

我的问题是什么应该是使用WhereIn / Contains的返回语句？

Answer 1

使用Google Guava：

过滤Collection个学生姓名

public Collection<String> findStudents(String filter) {

    Iterable<String> filteredStudents = Iterables.filter(listOfStudentNames, Predicates.containsPattern(filter));
    return Lists.newArrayList(filteredStudents);
}

过滤Collection<Student>

public Collection<Student> findStudents(String filter) {
  Iterable<Student> filteredStudents = Iterables.filter(listOfStudents, new Predicate<Student>() {
    @Override
    public boolean apply(Student student) {
      return student.getName().contains(filter);
    }
  }
}
return Lists.newArrayList(filteredStudents);

示例：

Iterable<String> filtered = Iterables.filter(Arrays.asList("asdf", "bsdf", "eeadd", "asdfeeee", "123"), Predicates.containsPattern("df"));

filtered现在包含[asdf, bsdf, asdfeeee]

Answer 2

例如类似的东西（返回新列表，不修改原始列表）

public Collection<Student> findStudents(List<Student> orgininalList, String filter) {
    List<Student> filteredList = new ArrayList<Student>();
    for(Student s : originalList) {
        if(s.getName().contains(filter)) {
            filterdList.add(s);
        }
    }
    return filteredList;
}

P.S注意“c.P.u1”的答案，Google Guava是非常有用的框架。

Answer 3

尝试类似

的内容

public Collection<Student> findStudents(String filter) {
  List<Student> students  = new ArrayList<Student>();

   //  filter  data 
   //if criteria match add to   students  

    return students;   
}

与Collection的值进行比较

3 个答案: