JAVA 装箱 拆箱 integer max_value

java笔记

装箱拆箱

简单数据类型
int
char
float

integer 装箱，拆箱

装箱拆箱1

装箱拆箱2

Integer i=10 装箱
i=i+1
j=i 拆箱

java integer max_value

public class Test {
public static void main(String[] args) {
Integer i=Integer.decode("123");
System.out.println(i);
//int j=12345678;
String s=Integer.toBinaryString(i);
System.out.println(s);
System.err.println(Integer.toHexString(i));
System.out.println(i.numberOfLeadingZeros(i));
}
}

日程表代码
``java
package reminder;
import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import javax.sound.midi.MidiSystem;
import javax.sound.midi.Receiver;
import javax.sound.midi.Sequence;
import javax.sound.midi.Sequencer;
import javax.sound.midi.Synthesizer;
import javax.sound.midi.Transmitter;
public class AlarmThread extends Thread {
    ReminderTest rm;
    public AlarmThread(ReminderTest rm) {
        this.rm = rm;
    }
    public void run() {
        try {
            File file = new File("onestop.mid"); // This is the file we'll be
                                                    // playing
            MidiSystem.getMidiFileFormat(file);
            Sequencer sequencer = MidiSystem.getSequencer(); // Used to play
                                                                // sequences
            sequencer.open(); // Turn it on.
            Synthesizer synth = MidiSystem.getSynthesizer();
            synth.open(); // acquire whatever resources it needs
            Transmitter transmitter = sequencer.getTransmitter();
            Receiver receiver = synth.getReceiver();
            transmitter.setReceiver(receiver);
            Sequence sequence = MidiSystem.getSequence(file);
            sequencer.setSequence(sequence);
            while (true) {
                System.out.println("alarm thread is running...");
                List<String> todoList = rm.txtToList();
                for (String s : todoList) {
                    String ss[] = s.split(";");
                    if (ss.length > 4) {
                        SimpleDateFormat sdf = new SimpleDateFormat("HH:mm");
                        String sd = sdf.format(new Date());
                        System.out.println(sd);
                        if (ss[4].startsWith(sd))
                            sequencer.start();
                    }
                }
                Thread.sleep(60000);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

//主程序
package reminder;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
public class ReminderTest {
    BufferedReader kbr;
    public ReminderTest() {
        this.kbr = new BufferedReader(new InputStreamReader(System.in));
    }
    // 读取文件到array list
    public List txtToList() {
        List<String> todoList = new ArrayList<String>();
        try {
            FileReader fr = new FileReader("日程.txt");
            BufferedReader br = new BufferedReader(fr);
            while (true) {
                String s = br.readLine();
                if (s == null)
                    break;
                todoList.add(s);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return todoList;
    }
    public void listToTxt(List<String> todoList) {
        try {
            File f = new File("日程.txt");
            BufferedWriter bw = new BufferedWriter(new FileWriter(f));
            for (int i = 0; i < todoList.size(); i++) {
                bw.write(todoList.get(i)+"\n");
            }
            bw.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    // 查看
    public void check() {
        List<String> todoList = txtToList();
        for (String s : todoList) {
            String ss[] = s.split(";");
            System.out.println("name:" + ss[0]);
            System.out.println("address:" + ss[1]);
            System.out.println("date:" + ss[2]);
            System.out.println("time:" + ss[3]);
            if (ss.length > 4)
                System.out.println("alarm:" + ss[4]);
            System.out.println("-----------------------------------");
        }
    }
    // 录入
    public void input() {
        List<String> todoList = txtToList();
        StringBuffer todo = new StringBuffer();
        String s = null;
        try {
            System.out.print("name:");
            s = kbr.readLine();
            todo.append(s).append(";");
            System.out.print("address:");
            s = kbr.readLine();
            todo.append(s).append(";");
            System.out.print("date(yyyy-mm-dd):");
            s = kbr.readLine();
            todo.append(s).append(";");
            System.out.print("time(hh:mm:ss):");
            s = kbr.readLine();
            todo.append(s);
            System.out.print("need alarm?(y/n)");
            s = kbr.readLine();
            if (s.equals("y") || s.equalsIgnoreCase("Y")) {
                System.out.print("alarm time:");
                s = kbr.readLine();
                todo.append(";").append(s);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        todoList.add(todo.toString());
        listToTxt(todoList);
    }
    // 删除【待修改】
    public static void Delete(int j) throws IOException {
        FileReader fr = new FileReader("日程.txt");
        BufferedReader br = new BufferedReader(fr);
        List<String> todoList = new ArrayList<String>();
        todoList.remove(j);
        File f = new File("日程.txt");
        BufferedWriter bw = new BufferedWriter(new FileWriter(f));
        for (int i = 0; i < todoList.size(); i++) {
            bw.write(todoList.get(i));
        }
        bw.close();
    }
// 修改【待修改】
    public void Change(int k, String x) throws IOException {
        FileReader fr = new FileReader("日程.txt");
        BufferedReader br = new BufferedReader(fr);
        List<String> todoList = new ArrayList<String>();
        todoList.set(k, x);
        File f = new File("日程.txt");
        BufferedWriter bw = new BufferedWriter(new FileWriter(f));
        for (int i = 0; i < todoList.size(); i++) {
            bw.write(todoList.get(i));
        }
        bw.close();
    }
    // 设置日期s,如果s和系统日期now相等，播放midi文件。
//主程序 【待修改】
    public static void main(String[] args) {    
        //
        ReminderTest rm = new ReminderTest();
        new AlarmThread(rm).start();
        rm.go();
    }
    void go(){
        while (true) {
            System.out.println("1:check todo list");
            System.out.println("2:input new todo");
            System.out.println("3:delete todo list");
            System.out.println("4:change todo list");
            System.out.println("5:set todo alarm");
            System.out.print("0:exit>>>>");
            String s=null;
            try {
                s = kbr.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            if (s.equals("1")) {
                check();
            } else if (s.equals("2")) {
                input();
            } else if (s.equals("3")) {
            }
              else if (s.equals("4")) {
            }
        }
    }
}