1.用代码实现以下需求
(1)定义学生类,包含姓名(String name),性别(String gender),年龄(int age)三个属性,生成空参有参构造,
set和get方法,toString方法
(2)键盘录入6个学员信息(录入格式:张三,男,25),要求有两个相同的信息,将6个学员信息存入到ArrayList集合中
(3)将存有6个学员信息的ArrayList集合对象写入到D:\\StudentInfo.txt文件中
(4)读取D:\\StudentInfo.txt文件中的ArrayList对象
(5)对ArrayList集合中的6个学生对象进行去重并按照年龄从小到大的顺序排序
(6)将ArrayList集合中排序后的结果利用PrintWriter流写入到E:\\StudentInfo.txt文件中(写入格式：张三-男-25)

我们还没学到这里.

已经搞定

public class Student implements Serializable{
private static final long StudentAge = 243563787868L;
private String name;
private int age;
private String gender;
public Student() {
super();

}
public Student(String name, String gender, int age) {
super();
this.name = name;
this.age = age;
this.gender = gender;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
@Override
public String toString() {
return "Student [name=" + name + ", age=" + age + ", gender=" + gender
+ "]";
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + age;
result = prime * result + ((gender == null) ? 0 : gender.hashCode());
result = prime * result + ((name == null) ? 0 : name.hashCode());
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Student other = (Student) obj;
if (age != other.age)
return false;
if (gender == null) {
if (other.gender != null)
return false;
} else if (!gender.equals(other.gender))
return false;
if (name == null) {
if (other.name != null)
return false;
} else if (!name.equals(other.name))
return false;
return true;
}


}
/*(1)定义学生类,包含姓名(String name),性别(String gender),年龄(int age)三个属性,生成空参有参构造,
set和get方法,toString方法*/

public class Tast1 {
public static void main(String[] args) throws IOException {
List<Student> list = new ArrayList<>();
studenAdd(list);
objectFile(list);
}
public static void objectFile(List<Student> list)
throws FileNotFoundException, IOException {
FileOutputStream fos = new FileOutputStream("f:\\StudentInfo.txt");
System.out.println(list);
ObjectOutputStream oos = new ObjectOutputStream(fos);
for(Student st : list){
oos.writeObject(st);
}
oos.close();
}
public static void studenAdd(List<Student> list) {
list.add(new Student("张三", "男",25));
list.add(new Student("李四", "男",21));
list.add(new Student("张三", "男",25));
list.add(new Student("赵六", "男",23));
list.add(new Student("李思", "女",20));
list.add(new Student("李蕾", "女",19));
list.add(new Student("阿强", "男",30));
}
}
/*1.用代码实现以下需求
(1)定义学生类,包含姓名(String name),性别(String gender),年龄(int age)三个属性,生成空参有参构造,
set和get方法,toString方法
(2)键盘录入6个学员信息(录入格式:张三,男,25),要求有两个相同的信息,将6个学员信息存入到ArrayList集合中
(3)将存有6个学员信息的ArrayList集合对象写入到D:\\StudentInfo.txt文件中
(4)读取D:\\StudentInfo.txt文件中的ArrayList对象
(5)对ArrayList集合中的6个学生对象进行去重并按照年龄从小到大的顺序排序
(6)将ArrayList集合中排序后的结果利用PrintWriter流写入到E:\\StudentInfo.txt文件中(写入格式：张三-男-25)*/
public class Tast1_1 {
public static void main(String[] args) throws ClassNotFoundException, IOException {
List<Student> list = new ArrayList<>();
listAdd(list);
paiXu(list);
FileWriter fw = new FileWriter("f:\\StudentInfo1.txt");
PrintWriter pw = new PrintWriter(fw,true);
for(Student st :list){
String name = st.getName();
String gender = st.getGender();
int age = st.getAge();
pw.println(name+"-"+gender+"-"+age);
}
pw.close();
fw.close();
}

public static void paiXu(List<Student> list) {
int min = list.get(0).getAge();
Student st = null;
min = 0;
for (int i = 0; i < list.size(); i++) {
for (int j = 0; j < list.size(); j++) {
if(list.get(i).getAge() < list.get(j).getAge()){
st = list.get(i);
list.set(i,list.get(j));
list.set(j, st);
}
}
}
}

public static void listAdd(List<Student> list)
throws FileNotFoundException, IOException, ClassNotFoundException {
Set<Student> set = new HashSet<Student>();
FileInputStream fis = new FileInputStream("f:\\StudentInfo.txt");
ObjectInputStream ois = new ObjectInputStream(fis);
Object obj = null;
Student st = (Student) obj;
while(fis.available()>0&&(st = (Student)ois.readObject()) != null){
//System.out.println(st);
boolean b = set.add(st);
if(b)
list.add(st);
}
ois.close();
//System.out.println(list);
}

KyneZhk 发表于 2017-2-19 19:01
排序直接在Student类里实现comparable接口重写compareTo方法然后直接调用sort就可以，简单多了
...

你这个应该映射了吧 ？