Java Collection/array sorting knowledge and IO-stream combination Example

1, keyboard input 5 Student information (name, language score, math results, English scores), according to the total score from high to low deposit text files.
Code:

public class Treesetdemo {public static void main (string[] args) throws ioexception{//Create TreeSet object, using the interface anonymous inner class Implement Comparator interface treeset<student> ts=new treeset<student> (New comparator<student> () {// Override the Compare () method in the comparator interface @Override public int compare (Student s1,student s2) {//main sort Bar            Pieces: Total, press from high to low output int num1=s2.sum (s2)-s1.sum (S1);               Secondary sorting criteria, when the total grade is the same, the int num2= (num1==0) is compared by the student name content? S2.getname (). Length ()-s1.getname (). Length (): NUM1;            return num2;        }               });        Keyboard entry Student Information System.out.println ("Please enter student information:");            for (int x=1;x<6;x++) {Scanner sc=new Scanner (system.in);            System.out.print ("Please enter the name of" +x+ "Student:");            String Name=sc.nextline ();            System.out.print ("Please enter the" +x+ "Student's language Score:");            int Chinesescore=sc.nextint ();            System.out.print ("Please enter the math score of" +x+ "Student:"); int Mathscore=sc.nextint();            System.out.print ("Please enter the" +x+ "Student's English Score:");            int Englishscore=sc.nextint ();            The input student information is encapsulated in the student object Student s=new Student ();            S.setname (name);            S.setchinesescore (Chinesescore);            S.setmathscore (Mathscore);            S.setenglishscore (Englishscore);        Add the Student object to the collection Ts.add (s);        }//create character buffer output stream object BufferedWriter bw=new bufferedwriter (New FileWriter ("18-1.txt")); Traverse for (Student s:ts) {//Take advantage of the APPEND function in StringBuffer to assemble the information that needs to be output StringBuffer sb=new Stringbuffe            R (); Sb.append (S.getname ()). Append (","). Append (S.getchinesescore ()). Append (","). Append (S.getmathscore ()). Append (","            ). Append (S.getenglishscore ()). Append (","). Append (S.sum (s));            Writes information to a text file in Bw.write (Sb.tostring ());            NewLine Bw.newline ();        Refresh Stream Bw.flush ();    }//Close stream, Release resource Bw.close (); }}

Console:

Text file:

2, the known s.txt file has such a string: "HCEXFGIJKAMDNOQRZSTUVWYBPL"
Please write the program to read the data content, sorting the data after writing to Ss.txt.

public class Paixv {    public static void main(String[] args) throws IOException {          // 读取该文件的内容,存储到一个字符串中          BufferedReader br = new BufferedReader(new FileReader("E:\\西部开源\\作业\\课后练习\\java\\18-2.txt"));          String line = br.readLine();          br.close();          // 把字符串转为字符数组          char[] chs = line.toCharArray();          // 对字符数组进行排序          Arrays.sort(chs);          // 把排序后的字符数组转换为字符串          String s = new String(chs);          // 把字符串再次写入ss.txt中          BufferedWriter bw = new BufferedWriter(new FileWriter("E:\\西部开源\\作业\\课后练习\\java\\18-2W.txt"));          bw.write(s);          bw.newLine();          // 释放资源          bw.close();     }}

Java Collection/array sorting knowledge and IO-stream combination Example