https://lingyicode.github.io/tags/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98/ Recent content in JDBC常见问题 on 凌奕 Hugo -- gohugo.io en-us 凌奕 Sat, 11 Oct 2025 11:06:00 +0800 https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/ Mon, 25 Aug 2025 14:25:45 +0800 https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/ <img src="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/preview.jpg" alt="Featured image of post JDBC常见问题及异常处理详解" /><h1 id="jdbc常见问题">JDBC常见问题 </h1><h2 id="资源的管理">资源的管理 </h2><p>在使用jdbc的相关资源时，比如Connection、PreparedStatement、ResultSet，使用完毕后，要及时关闭这些资源以<code>释放数据库服务器资源</code>和<code>避免内存泄露</code>等问题。</p> <p><img src="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/One.png" width="1196" height="548" srcset="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/One_hu_b7426dd3b4348038.png 480w, https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/One_hu_e4546e43c05ffc2b.png 1024w" loading="lazy" alt="关闭资源" class="gallery-image" data-flex-grow="218" data-flex-basis="523px" ></p> <h2 id="sql问题">SQL问题 </h2><h3 id="sql语句问题">SQL语句问题： </h3><ul> <li>java.sql.SQLSyntaxErrorException</li> </ul> <p><img src="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLYJ.png" width="620" height="312" srcset="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLYJ_hu_64a7164903efda7b.png 480w, https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLYJ_hu_60fdfaad227401a1.png 1024w" loading="lazy" alt="SQLSyntaxErrorException" class="gallery-image" data-flex-grow="198" data-flex-basis="476px" ></p> <blockquote> <p>java.sql.SQLSyntaxErrorException：SQL语句错误异常，一般有几种可能：</p> </blockquote> <blockquote> <p>1.<code>SQL语句错误</code>，检查SQL语句，建议SQL语句在SQL工具(navicat、dataGrip)中测试后再赋值到java程序中。</p> </blockquote> <blockquote> <p>2.连接数据库的URL中，<code>数据库名称编写错误</code>，也会报该异常。</p> </blockquote> <h3 id="sql语句未设置参数问题">SQL语句未设置参数问题 </h3><ul> <li>java.sql.SQLException: No value specified for parameter 1</li> </ul> <p><img src="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLCS.png" width="661" height="204" srcset="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLCS_hu_aa94163b3a513df3.png 480w, https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLCS_hu_180f320b3cce5878.png 1024w" loading="lazy" alt="No value specified for parameter 1" class="gallery-image" data-flex-grow="324" data-flex-basis="777px" ></p> <blockquote> <p>在用预编译SQL语句时，如果有<code>?占位符</code>，要为每一个占位符赋值，否则报该错误。</p> </blockquote> <h3 id="用户名或密码错误">用户名或密码错误 </h3><p><img src="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLYM.png" width="644" height="148" srcset="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLYM_hu_f499a345081b073.png 480w, https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLYM_hu_b9e6aa2eaa008121.png 1024w" loading="lazy" alt="name or password" class="gallery-image" data-flex-grow="435" data-flex-basis="1044px" ></p> <blockquote> <p>在连接数据库时，如果<code>用户名或密码输入错误</code>，也会报SQLException，容易混淆，看清异常后面原因描述</p> </blockquote> <h3 id="通信异常">通信异常 </h3><ul> <li> <p>com.mysql.cj.jdbc.exceptions.CommunicationsException:Communications link failure</p> <p><img src="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLTX.png" width="662" height="153" srcset="https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLTX_hu_6b81a63add46b1a9.png 480w, https://lingyicode.github.io/post/jdbc%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98%E5%8F%8A%E5%BC%82%E5%B8%B8%E5%A4%84%E7%90%86%E8%AF%A6%E8%A7%A3/SQLTX_hu_2119d5d76e67d837.png 1024w" loading="lazy" alt="CommunicationsException" class="gallery-image" data-flex-grow="432" data-flex-basis="1038px" ></p> </li> </ul> <blockquote> <p>在连接数据库URL时，如果IP端口或端口写错了，会报以上异常</p> </blockquote>