java - java程序连接JSON数据库(记事本+命令提示符)

Question

所以我一直在寻找将我创建的 JSON 数据库连接到 Java 程序的方法，我似乎找不到适合这种特定情况的任何内容，因此我尝试使用 JDBC 教程(http://www.tutorialspoint.com/jdbc/index.htm )，尽管我遇到了一些问题。

我有什么 -我的数据库用于设置连接的示例程序(我尝试用它来实现 json，这是我最大的一些问题)json 库(我相信我已经成功地将它们添加到我的类路径中，尽管这就是我设法找出如何做的全部)

我使用的是什么版本/类似版本 -带有记事本和命令提示符的 java ( j2sdk1.4.2 )json-lib-2.4-jdk13(总共 3 个 jar 文件 - 下载自:https://sourceforge.net/projects/json-lib/files/json-lib/json-lib-2.4/)

这是我的示例程序(未更改的示例代码可以在上面的 tutorialspoint.com 链接中找到，位于页面左侧的 JDBC - 示例程序部分下。):

import java.sql.*;

public class DatabaseTest
{

static final String JGBC_DRIVER = "com.json.jdbc.Driver"; 
    //Tutorial had the following: com.mysql.jdbc.Driver
static final String DB_URL = "";
   //Tutorial states: jdbc:mysql://localhost/EMP, though I saw something that was 

//基本上说不同的数据库类型有不同的格式...

static final String USER = "test";
static final String PASS = "password";

public static void main(String[]args) 
{
    Connection conn = null;
    Statement stmt = null;

    try
    {
        Class.forName("com.json.jdbc.Driver");

        System.out.println("Connecting to database");
        conn = DriverManager.getConnection(DB_URL,USER,PASS);

        System.out.println("Creating statement...");
        stmt = conn.createStatement();
        /*String sql;  This section is commented so I could javac 
        *(clearing out whatever errors I could
        * tutorial then states the following, however I believe this 
        *is specific to a database format
        *sql = "SELECT id, first, last age FROM Employees";
        *The following line is how I think it would work with JSON...
        *
        *sql = Elements[0];
        *
        *ResultSet rs = stmt.executeQuery(sql);
        *
        *while(rs.next())
        *{
        *   String strName = rs.getString(name);
        *   System.out.println("Element name: " + strName);
        *}
        *
        rs.close();
        */
        stmt.close();
        conn.close();
    }catch(SQLException se){
        se.printStackTrace();
    }catch(Exception e){
        e.printStackTrace();
    }finally{
        try
        {
            if(stmt != null)
                stmt.close();
        }catch(SQLException se2){
        }
        try
        {
            if(conn != null)
                conn.close();
        }catch(SQLException se){
            se.printStackTrace();
        }
    }
    System.out.println("Goodbye!");
}
}

这是我的数据库的一部分(它包含元素周期表的信息，遍历所有 118 种元素)。

出于测试目的，我只想获取 Elements 数组中第一个对象的属性(即“Hydrogen”)

{
"Elements" : [
    {
    "name" : "Hydrogen",
    "Symbol" : "H",
    "atomicNumber" : "1",
    "electronegativity" : "2.2",
    "group" : "Hydrogen",
    "ionCharge1" : "1+",
    "ionCharge2" : "1-",
    "molarMass" : "1.01",
    "naturalState" : "Gas",
    "synthetic" : "false",
    "diatomic" : "true",
    "columnNumber" : "1",
    "columnCode" : "IA",
    "row" : "1",

    "nobleGasConfiguration" : [
        {
        "term:" : "No Noble Gas Configuration",
        "superScript" : "-"
        }
    ],
    "electronConfiguration" : [
        {
        "term" : "1s",
        "superScript" : "1"
        }
    ]
    },
    {
    "name" : "Helium",
    "Symbol" : "He",
    "atomicNumber" : "2",
    "electronegativity" : "-",
    "group" : "NobleGas",
    "ionCharge1" : "-",
    "ionCharge2" : "-",
    "molarMass" : "4.00",
    "naturalState" : "Gas",
    "synthetic" : "false",
    "diatomic" : "false",
    "columnNumber" : "18",
    "columnCode" : "VIIIA",
    "row" : "1",

    "nobleGasConfiguration" : [
        {
        "term" : "[He]",
        "superScript" : "-"
        }
    ],      
    "electronConfiguration" : [
        {
        "term" : "1s",
        "superScript" : "2"
        }
    ]       
    },
    {
    "name" : "Lithium",
    "Symbol" : "Li",
    "atomicNumber" : "3",
    "electronegativity" : "1.0",
    "group" : "AlkaliMetal",
    "ionCharge1" : "1+",
    "ionCharge2" : "-",
    "molarMass" : "6.94",
    "naturalState" : "Solid",
    "synthetic" : "false",
    "diatomic" : "false",
    "columnNumber" : "1",
    "columnCode" : "IA",
    "row": "2",

    "nobleGasConfiguration" : [
        {
        "term" : "[He]",
        "superScript" : "-"
        },
        {           
        "term" : "2s",
        "superScript" : "1"
        }
    ],
    "electronConfiguration" : [
        {
        "term" : "1s",
        "superScript" : "2"
        },
        {
        "term" : "2s",
        "superScript" : "1"
        }
    ]       
    },
}

问题 -对于静态最终字符串 DB_URL = "";我应该为 JSON 使用什么格式？

我相信我仍然需要导入 JSON 的东西，但我无法找到如何(如顶部所述，我已经得到的最远的是将我下载的 3 个 jar 添加到我的类路径).所以这引出了我的问题，我如何导入我下载并添加到我的类路径中的库？

Answer 1

您的 DB_URL 应该是您的数据库的路径 - 如果没有数据库的路径，Java 应用程序将不知道在哪里查询数据库。再次使用教程中的示例(jdbc:mysql://localhost/STUDENTS)