我正在使用java 11和SQLite 3.30.1制作一个桌面Windows PC应用程序。在我的sql表 "Alarms "中,我有一个日期(DATETIME)列,我试图使用jdbc resultset.getTimestamp()来检索它。但我得到以下错误。"java.sql.SQLException.Error parsing time stamp": 错误解析时间戳"。因为这是一个报警管理器,我想存储日期+时间。我还希望能够从一个日期中分出两个日期。
CREATE TABLE "alarms" (
"id" INTEGER NOT NULL,
"date" DATETIME NOT NULL,
"name" TEXT,
"text" TEXT NOT NULL,
PRIMARY KEY("id")
);
这是我的Alarms java类:
import java.io.Serializable;
import java.sql.Timestamp;
public class Alarms implements Serializable {
private int id;
private Timestamp date;
private String name;
private String text;
public Alarms() {
}
public Alarms(int id, Timestamp date, String name, String text) {
this.id = id;
this.date = date;
this.name = name;
this.text = text;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public Timestamp getDate() {
return date;
}
public void setDate(Timestamp date) {
this.date = date;
}
public String getText() {
return text;
}
public void setText(String text) {
this.text = text;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return name;
}
}
这是我的java jdbc方法:
public ObservableList<Alarms> getAlarms() {
alarmsList.clear();
try {
s = "SELECT * FROM alarms";
statement = connection.createStatement();
resultSet = statement.executeQuery(s);
while (resultSet.next()) {
Alarms al = new Alarms();
al.setId(resultSet.getInt(1));
al.setDate(resultSet.getTimestamp(2));
al.setName(resultSet.getString(3));
al.setText(resultSet.getString(4));
alarmsList.add(al);
}
return alarmsList;
} catch (SQLException throwables) {
throwables.printStackTrace();
}
return null;
}
所以问题是,我如何在SQLite中使用jdbc存储,插入和检索Date+time? 我做错了什么?
经过一整天的搜索,我找到了一个解决方案。在你的SQLite表中,你可以完美地使用DATETIME来存储日期+时间,SQLite会将其存储为字符串。我的表是这样的。
CREATE TABLE "alarms" (
"id" INTEGER NOT NULL,
"date" DATETIME NOT NULL,
"name" TEXT,
"text" TEXT NOT NULL,
PRIMARY KEY("id")
);
由于SQLite返回的是一个字符串, 你必须在java的结果集上使用 "getString()". 这个字符串是一个Long的数字,比如1588370406005.所以我必须在我的Alarms java类中添加一些额外的getter和setter.这是我的Alarm java类。
import java.io.Serializable;
import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZoneOffset;
public class Alarms implements Serializable {
private int id;
private LocalDateTime date;
private String name;
private String text;
public Alarms() {
}
public Alarms(int id, LocalDateTime date, String name, String text) {
this.id = id;
this.date = date;
this.name = name;
this.text = text;
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public LocalDateTime getDate() {
return date;
}
public String getDateStringFormat(){
return Long.toString(date.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli());
}
public void setDate(LocalDateTime date) {
this.date = date;
}
public void setDate(String stringDate){
date= Instant.ofEpochMilli(Long.parseLong(stringDate)).atZone(ZoneId.systemDefault()).toLocalDateTime();
}
public String getText() {
return text;
}
public void setText(String text) {
this.text = text;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Override
public String toString() {
return name;
}
}
我的JDBC方法是:
public ObservableList<Alarms> getAlarms() {
alarmsList.clear();
try {
s = "SELECT * FROM alarms";
statement = connection.createStatement();
resultSet = statement.executeQuery(s);
while (resultSet.next()) {
Alarms al = new Alarms();
al.setId(resultSet.getInt(1));
al.setDate(resultSet.getString(2));
al.setName(resultSet.getString(3));
al.setText(resultSet.getString(4));
alarmsList.add(al);
}
return alarmsList;
} catch (SQLException throwables) {
throwables.printStackTrace();
}
return null;
}
希望这能帮助到别人。