每日总结

今天练习了数据库的添加，学习了日期的获取

package com.example.meiri;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import com.example.meiri.db.PunchHelper;

import java.text.SimpleDateFormat;
import java.util.Date;

public class record extends AppCompatActivity {

    private PunchHelper punchHelper;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_record);

//      声明
        TextView et_date = findViewById(R.id.rd_tv_date);   //日期
        ImageView iv_back = findViewById(R.id.rd_iv_back);  //返回
        Button bt_punch = findViewById(R.id.rd_bt_punch);   //打卡
        EditText ed_keys = findViewById(R.id.rd_ed_keys);   //关键字
        EditText ed_text = findViewById(R.id.rd_ed_text);   //内容
        EditText ed_day = findViewById(R.id.rd_ed_days);    //坚持天数
        EditText ed_maxday = findViewById(R.id.rd_ed_maxday);   //连续最长天数

//      时间显示
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyy年MM月MM日");
        Date date = new Date(System.currentTimeMillis());
        et_date.setText(simpleDateFormat.format(date));

//        返回
        iv_back.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(record.this, MainActivity.class);
                startActivity(intent);
                finish();
            }
        });

        bt_punch.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String date = et_date.getText().toString().trim();
                String keys = ed_keys.getText().toString().trim();
                String text = ed_text.getText().toString().trim();
                String maxday = ed_maxday.getText().toString().trim();
                String day = ed_day.getText().toString().trim();

//                判断输入是否为空
                if (!TextUtils.isEmpty(keys) && !TextUtils.isEmpty(text) && !TextUtils.isEmpty(maxday)){
                    punchHelper.add(date,keys,text,day,maxday);
                    Intent intent1 = new Intent(record.this, MainActivity.class);

                    startActivity(intent1);
                    finish();
                    Toast.makeText(record.this, "打卡成功", Toast.LENGTH_SHORT).show();

                }
                else {
                    Toast.makeText(record.this, "基本项目未填写完整", Toast.LENGTH_SHORT).show();
                }
            }
        });

        punchHelper = new PunchHelper(record.this);

    }
}

日期

public class SimpleDateFormat extends DateFormat {

    // the official serial version ID which says cryptically
    // which version we're compatible with
    static final long serialVersionUID = 4774881970558875024L;

    // the internal serial version which says which version was written
    // - 0 (default) for version up to JDK 1.1.3
    // - 1 for version from JDK 1.1.4, which includes a new field