Android 代码示例：比较日期与当前日期的先后关系

以下是一个示例的 Android 代码，用于比较给定日期与当前日期的先后关系：

import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;public class MainActivity extends AppCompatActivity {\n    @Override\n    protected void onCreate(Bundle savedInstanceState) {\n        super.onCreate(savedInstanceState);\n        setContentView(R.layout.activity_main);\n\n        // 获取当前日期\n        Calendar calendar = Calendar.getInstance();\n        Date currentDate = calendar.getTime();\n\n        // 定义给定日期字符串\n        String date1String = "2022-12-08";\n        String date2String = "2023-08-22";\n        String date3String = "2023-09-20";\n\n        // 将给定日期字符串转换为Date对象\n        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");\n        Date date1 = null;Date date2 = null;Date date3 = null;try {\n            date1 = sdf.parse(date1String);\n            date2 = sdf.parse(date2String);\n            date3 = sdf.parse(date3String);\n        } catch (ParseException e) {\n            e.printStackTrace();\n        }\n\n        // 比较给定日期与当前日期的先后关系\n        if (date1 != null && date1.before(currentDate)) {\n            Log.d("Date Comparison", date1String + " is before today.");\n        } else if (date1 != null && date1.after(currentDate)) {\n            Log.d("Date Comparison", date1String + " is after today.");\n        } else {\n            Log.d("Date Comparison", date1String + " is today.");\n        }\n\n        if (date2 != null && date2.before(currentDate)) {\n            Log.d("Date Comparison", date2String + " is before today.");\n        } else if (date2 != null && date2.after(currentDate)) {\n            Log.d("Date Comparison", date2String + " is after today.");\n        } else {\n            Log.d("Date Comparison", date2String + " is today.");\n        }\n\n        if (date3 != null && date3.before(currentDate)) {\n            Log.d("Date Comparison", date3String + " is before today.");\n        } else if (date3 != null && date3.after(currentDate)) {\n            Log.d("Date Comparison", date3String + " is after today.");\n        } else {\n            Log.d("Date Comparison", date3String + " is today.");\n        }\n    }\n}

这段代码首先获取当前日期，然后将给定的日期字符串转换为Date对象，最后使用before()和after()方法将给定日期与当前日期进行比较，根据比较结果输出相应的日志信息。