java.lang.ClassNotFoundException: org.postgresql.Driver, Android [英] java.lang.ClassNotFoundException: org.postgresql.Driver, Android

问题描述

我在 Windows 上运行 Eclipse.

I am running Eclipse on Windows.

遵循本教程，我下载了 JDBC4，使用 Project 将其添加到我的构建路径中>属性>添加外部 JAR，浏览文件，它起作用了(.classpath 文件显示了正确的 lib 路径).

Following this tutorial I downloaded JDBC4, added it to my build path using Project>Properties>add External JAR, browsed for the file, it worked (.classpath file shows the correct lib path).

该包出现在我的 Referenced Libraries 文件夹中，所以我继续本教程.

The package appears in my Referenced Libraries folder, so I continue the tutorial.

    import java.sql.Connection;
    import java.sql.DriverManager;
    import java.sql.PreparedStatement;
    import java.sql.SQLException;

    ....

    public void open ()
        {
    try {
        Class.forName("org.postgresql.Driver");
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    }

    try {
        conn = DriverManager.getConnection(url, username, password);
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

我认为就这么简单，但是我遇到了这个以

I think it would be as simple as that but I get hit with this big long stack trace starting with

    java.lang.ClassNotFoundException: org.postgresql.Driver

(如果需要，我可以提供更多)

(I can provide more if needed)

我试过 include org.postgresql.*; 但这也没有帮助.我也尝试过 JDBC3，但也没有运气.

I tried include org.postgresql.*; but that didn't help either. I have also tried the JDBC3 but no luck there either.

我查看了 Driver JDBC PostgreSQL with Android，它提供了一个模糊的答案，说我只使用 HTTP+JSON 会更好.我从来没有用过.

I looked at Driver JDBC PostgreSQL with Android which provided a vague answer saying I would be better off just using HTTP+JSON. Which I have never used.

我是 Android、postgresql、Web 开发的新手，所以如果能提供简单的答案，我们将不胜感激.

I'm brand new to Android, postgresql, web development, so a simple answer would be appreciated.

推荐答案

您需要在您的项目中添加 PostgreSQL JDBC 驱动程序，如 search.maven.org.

You need to add the PostgreSQL JDBC Driver in your project as mentioned in search.maven.org.

Gradle:

implementation 'org.postgresql:postgresql:42.2.10'

Maven:

<dependency>
  <groupId>org.postgresql</groupId>
  <artifactId>postgresql</artifactId>
  <version>42.2.10</version>
</dependency>

您还可以下载 JAR 并导入到您的项目中手动.

You can also download the JAR and import to your project manually.

注意:不推荐使用此答案中使用的编译.根据 3 替换为实现.

NOTE: Compile as used in this answer is deprecated. Replace with implementation as per 3.

这篇关于java.lang.ClassNotFoundException: org.postgresql.Driver, Android的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！