小编Mr *_*ker的帖子

我试图min distance, min speed and max speed在我的查询结果中获取记录 .目前我的距离最短,但我面临着获得最小和最大速度的问题,我问自己是否有可能public int compareTo(BehaviourItem otherItem)在BehaviourItem课堂上添加另一种方法来达到这个目的但是我得到了错误 Duplicate method compareTo(BehaviourItem) in type BehaviourItem.

如何从BehaviourItem课堂上获得最低和最高速度？

码:

         PreparedStatement prepared = con
                 .prepareStatement("SELECT speed, stop_distance from behaviour where mac = ? and stop_name = ?");
                 prepared.setString(1, macD);
                 prepared.setString(1, sto_nam);
                 ResultSet rsBehav = prepared.executeQuery();
                 List<BehaviourItem> behavList = new ArrayList<BehaviourItem>();
                 while (rsBehav.next()) {
                     int distance = rsBehav.getInt("stop_distance");
                     int speed = rsBehav.getInt("speed");
                     BehaviourItem behItem = new BehaviourItem(distance, speed);
                     behavList.add(behItem);

                 }
                 Collections.sort(behavList);
                 int minDistance …

我试图获取最小值的索引,但是当第一个元素的最小值为570(索引= 0)时,我收到此错误.我究竟做错了什么？

码:

//ArrayList of distanceList [570, 621, 716, 906, 1055, 1253, 1314, 1314]
ArrayList<Integer> distanceList = entry.getValue();
//min is 570
int min = Collections.min(distanceList);
int index = distanceList.get(min);

错误:

threw exception [java.lang.IndexOutOfBoundsException: Index: 570, Size: 8] with root cause
java.lang.IndexOutOfBoundsException: Index: 570, Size: 8
    at java.util.ArrayList.rangeCheck(ArrayList.java:635)
    at java.util.ArrayList.get(ArrayList.java:411) 

我试图检查数组中两个字符串的位置是否不同.例如,如果我有字符串apple和字符串,appendix那么两个字符串在i = 3的位置是不同的.

如何用Java检查？

码

 //The first string is s.
    char[] cArray = s.toCharArray();
    // The seond string is root.edge.
    char[] rootEdgeCharacter = root.edge.toCharArray();

    for(int i=0; i<cArray.length; i++  ){
        for(int j=0; j<rootEdgeCharacter.length; j++){
            if(cArray[i]== rootEdgeCharacter[j]){
                System.out.println("The String are different where i =" + i);

            }
        }
    }   

我想将项目推送到github主页.因此,我正在尝试为github创建ssh-key来管理它,但我遇到的问题是git在错误的目录中/c/Users/user82/.ssh/id_rsa)而不是在项目目录中创建了ssh-key /desktop/dogs.

我怎么能告诉Git在项目目录中创建ssh-key /desktop/dogs而不是在这个目录中c/Users/user82呢？

user82@User MINGW64 ~/desktop/dogs (master)
$ ssh-keygen -t rsa -C "example@gmail.com"
Generating public/private rsa key pair.
Enter file in which to save the key (/c/Users/user82/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /c/Users/user82/.ssh/id_rsa.
Your public key has been saved in /c/Users/user82/.ssh/id_rsa.pub.

我试图将数据插入到我的停止表中,stops表和route正在创建的表,但程序无法将数据插入停止表,我收到此错误:

Unknown column '1' in 'field list'

我感谢任何帮助.

    stt.execute("CREATE TABLE IF NOT EXISTS routes"
             + "(route_id INT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY, "
             + "route INT(11) NOT NULL)" );
    stt.execute("INSERT INTO routes(route) VALUES"
            + "(1),"
            + "(9)");

    stt.execute("CREATE TABLE IF NOT EXISTS stops"
            + "(stop_id INT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY, "
            + " name varchar(30) NOT NULL, "
            + " lat double(10,6) NOT NULL, "
            + " longi double(10,6)NOT NULL,"
            + "route_id INT, FOREIGN KEY …

我正在尝试学习Hibernate框架hibernate-release-5.1.0.Final.我已经包括了所有必需的罐子lib\required, lib\jpa, und lib\java8.请看下面的屏幕截图,我hb_student_tracker为Student类创建了一个数据库但是我收到的错误如下Caused by: java.lang.ClassNotFoundException: Could not load requested class : models.Category 我正在使用XAMPP控制面板的默认配置.用户名也是root密码.

hibernate.cfg.cml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM 
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/hb_student_tracker</property>
        <property name="connection.username">root</property>
        <property name="connection.password"></property>

        <property name="connection.pool_size">1</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="current_session_context_class">thread</property>
        <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
        <property name="show_sql">true</property>
        <property name="hbm2ddl.auto">validate</property>

        <mapping class ="models.Category" />

    </session-factory>
</hibernate-configuration>

学生

package com.tutorial.hibernate.demo.entity;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="student")
public class Student {
    @Id
    @Column(name="id")
    private int …